Water Conservation Archives - Christiane Holmquist Landscape Design

San Diego … Drought Proof Your Landscape, Part 2

March 26, 2014 By Christiane Holmquist 2 Comments

Xeriscape landscaping can be colorful, water-saving and rewarding

In my previous post, San Diego … Drought Proof Your Landscape, Part 1, I explained the term “xeriscape” and outlined several water-smart landscaping ideas and the first steps towards a water-wise landscape that is beautiful and yet sustainable. Here are the remaining steps a well as valuable resources.

5. Now that you are making voids in your garden (by eliminating certain unsustainable plants), perhaps it’s time to splurge on a few new hardscape elements (patios, walkways, shade pergolas)?

In my mind a garden is only a place worth caring for when it comes to life with plants. However, our landscapes need structure and good organization if they are to be enjoyable. And to enjoy them usually means entertainment, relaxation, rejuvenation, and also play and reconnecting with nature in the privacy of our home.

A shade cover allows daylong use of the patio

Patios, decks or terraces:

They have an immensely popular and well-deserved status in our landscape. If comfort and peace eludes you on your patio there’s no incentive to be out in the garden much…

it needs to be big enough to be comfortable;
it needs to be paved with safe and appealing materials;
it needs to be sheltered from sun, wind or the curiosity of our neighbors;
it needs to be comfortably accessible from the kitchen when food is carried outside to the dining or lounging table.

Walkways in the garden expand your enjoyment of it

If you find that any of these elements is missing from your entertainment/relaxation space, now might be the time to remedy these shortcomings and create a comfortable outdoor entertainment space design. Perhaps a new pavement is needed, or a shade device? This could be a pergola, an umbrella or shade sails, or (most practical perhaps or economical) a shade tree!

And new pathways? Imagine going on a discovery tour in your garden and enjoying your creativity, admiring what all the beautiful drought tolerant plants are showing off through the seasons. A discovery path that winds around your new planter beds, or a strolling path leading to a bench or comfortable seat at the rear end of your garden could be a long lasting addition that will pay off many-fold.

6. Mulch – too often overlooked

A good-looking mulch helps save water and gives it all a finished look

A thick layer of mulch, spread around all plants is so important! It should be 2-3 inches thick, or the kind that includes also small pieces (not the nuggets or the shredded lumber), and not smothering the root crown (the part where the roots converge into the stems just at/above soil level) to avoid fatal fungus disease.

A layer like this is attractive, makes your plants stand out, cools and enriches the soil, prevents erosion from rain or hard irrigation, and slows down evaporation. It’s a big water saver, and whatever has decomposed during the year, needs to be replenished in the following spring.

Some landscape are well served with an inorganic layer of mulch, made from decomposed granite or crushed rock. These materials are well suited to Southwest landscape designs or “desert-scapes”, and this type of mulch, although not enriching the soil, can help reduce evaporation and gives a finished look.

7. Know your soil

Knowing your soil texture helps determine what to plant, how to irrigate and how to amend your soil

Knowing whether you have sandy, loamy or high clay soil lets you determine whether to “condition” your soil (by adding compost, organic matter, or other ingredients such as gypsum), which irrigation system to use, how fast water drains into the sub soil and when to irrigate again. It also helps you determine which plants are best for your location. In my mind it’s not as necessary to add nutrients — most of the drought tolerant plants come from areas with nutrient-poor soil — as it is to have organic matter in your soil as this organic matter, as it decomposes, feeds more micro-organisms and creates a healthier environment for plants. So adding compost for example helps you improve your soil.

This Homeowner’s Guide to a WaterSmart Landscape Flipbook helps you determine this question.

8. Hand-watering; still a smart irrigation technique?

Hand-watering helps to “spot water” only the plants that you want to save

If you have a mature tree in your landscape that “never gets any (irrigation) water”, you might think you don’t need to water this specimen.

However, it’s important to consider that our winter was very dry, and that “established plants” can get by without extra water – only if they can tap into a reservoir of soil that was re-hydrated in the winter. With our meager rainfall this winter, there’s nothing much to tap into… I’d get a hose-end sprinkler device , one that you can set on the ground, at the end of your garden hose, and a simple kitchen timer, and give this so important asset in your garden a few deep soakings. It’s important to note that a tree that is stressed doesn’t show its stress right away; it might take a couple to a few years until the stress invites insect attack, tip dying, and eventual demise.

What’s deep soaking? Only a soil moisture measuring device, such as auger or soil tube, can prove that your water has sunk in deeply. For a tree that means 18 to 24 inches because in this layer of soil trees usually have about 90 % of their roots.

9. Investigate where your irrigation system might be wasting water.

Sad thing to see so much water land on the driveway

It has been shown in numerous studies that the traditional sprinkler heads and rotors have a mere 50% efficiency rate, and you can observe in your neighborhood (if not in your own garden), how much of runs off before it can get to the plants (such on compacted turf for example, or on slopes); or how much gets blown away by the wind, or how much of lands on driveways or sidewalks.

The modern low-volume spray systems or drip are much more efficient, and water used these systems go much farther.

10. Irrigate wisely – not miserly.

Most trees’ feeder roots are to be found in the top 18-24 inches

The word is “deep watering”, not frequent… This has to do with your plants root systems: For trees about 90% of their roots are in the top 1-2 feet; for larger shrubs a bit less, and for perennials about 6 inches. (These are very rough generalizations and can be fine-tuned depending on the plants that you want to water.)

To water a drought tolerant plant, you might think you don’t need to water much. That’s ultimately the goal, but it’s important to visualize the root system of this plant:

At planting time all the roots of this plant are in a small confined space – a 1 gal or a 5 gal pot, or larger – and if this plant is not allowed to stretch its roots out far and deep, it will never be ‘drought tolerant’! The establishment phase therefore is crucial: During this phase the water needs to be applied regularly and deeply.

To determine how long then your irrigation system needs to run, you will need to a percolation test.

11. Invest in a smart irrigation system

Not only is low-volume irrigation more efficient at watering your landscape and therefore wastes less water, it can be combined with a “smart irrigation controller”. This device is tied into weather stations (the better ones even have local sensors) that measure your local temperatures, even relative humidity, solar radiation, and water loss due to evaporation. Combined with your input of the type of plants that you want to water, your soil type and your type of irrigation system it calculates how much and when to water.

If this process is over your head, there are many local companies that offer help with this smart system. (check out the CLCA website for qualified landscape companies. Also the Irrigation Association and American Society of Irrigation Consultants)

Lastly, it’s very useful to locate any leaks or breaks that your system might have, and to do a pressure test: Pressure that’s too high can cause more wind-born water and runoff than you want to pay for…A pressure regulator can achieve valuable water savings.

Water Conservation Resources

This bench invites to rest here for a while

Here an EPA overview of ‘smart sense controllers’: www.EPA.gov/WaterSense

The San Diego County Water Authority has a very useful website. It lists numerous resources related to water conservation:
www.BeWaterWise.com

To see how beautiful water-conserving plants can be, the The Water Conservation Garden’s water-wise demonstration garden is a must-visit.

The Landscape Watering Calculator computes individualized watering requirements.

The California Friendly Garden Guide searchable plant database and other useful features.

San Diego County Water Authority 20-Gallon Challenge information.

On this website you’ll also find more educational resources for students and teachers.

San Diego … Drought Proof Your Landscape

February 28, 2014 By Christiane Holmquist 8 Comments

Orange blossoms draw lots of admirers

Here’s what you can do to protect your landscape during San Diego’s drought and to do it in style, incidentally.

Yesterday morning I stepped outside with my breakfast cereal to soak in the warm sunshine and see what’s going on in my garden. Following the buzz of the bees drawn by the sweet scent of Orange blossoms wafting through the garden, I found the Orange tree covered with flowers – what a joy to see!

Taking a deep breath, my eyes scanned the garden, and it struck me that the Plum tree also had started to bloom, and the first Cleveland Sages, and then, coming around my deck, I saw that the Wisteria, pruned barely a few weeks ago, had pushed out big buds ready to open at any moment! But winter is hardly over officially, or is it?

With all the delight over warmth and gorgeous spring bloom, I can’t help feeling concern about how soon summer will be here, and how my garden will fare with the watering restrictions that are sure to come?

If you, too, can’t help looking anxiously skywards waiting for rain, and wondering how you can protect your landscape from the effects of drought, read on: Here I’ll outline important ideas and tips to help you protect your garden investment and “drought proof” it through the months to come.

Xeriscape – the technique to garden sustainably and colorfully in a dry climate

A successful xeriscape brims with color

Like it or not, you’ll get to hear this word more and more often as people are discussing ways to create and safe-guard a home landscape design that is attractive and sustainable with limited or no extra applications of water. (BTW: People in consistently hot and dry climates such as Arizona, New Mexico, Nevada are already well familiar with these design parameters.)

As Wikipedia describes it: “Xeriscaping is landscaping and gardening that reduces or eliminates the need for supplemental water from irrigation. “ It most definitely does not mean ‘zero – scaping’ although it’s easy to pronounce the word that way.

So where does this process of transforming and protecting your landscape as a sustainable xeriscape start?

The following steps are very important and will help you preserve your landscape and safeguard it against drought.

1. Decide what to water and what not.

A young Tipu tree is worth protecting from under-watering

Water is scarce, and watering all of your landscape will be very costly and difficult if not impossible if San Diego goes back to specific days for irrigation. Also, if you have a traditional irrigation system, your irrigation cycles will be even more restricted.

It’s therefore wise to only water what’s really valuable in your landscape. It helps to be cold-hearted and examine each plant for its benefits and assets, as well it’s cost in maintenance, water, fertilizer. This is one of the most important steps on your way to water conservation. So how do you put a value on the plants in your landscape?

I always start “from the top down”, that is with the largest specimen, the trees. A young tree that has already been in the ground for a few years and that is showing promise is definitely worthy of special watering. A mature tree is hard to replace, and it has taken many years and much care to get it to that stage so deserves saving.

A mature tree in the landscape that provides lovely shade is hard to replace

But here, too, I recommend checking whether it really does what it’s supposed to do: Does is shade your house or patio, saving energy in hot weather? Does it provide fruit? Does it provide privacy or screen a bad view? Don’t forget also that if placed right, a tree is a design element that “anchors” your home to its environment and adds an important vertical element and a focal point to your landscape.

Now if your tree doesn’t do much of the before listed jobs; if instead it dwarfs your house, sheds needles on your roof or spiky seeds on your patio… If it threatens to drop its branches on your car or the neighbor’s yard… Perhaps it’s the first on your let-go-list?

2. And so you continue with the shrubs, and then the other smaller plants, and then perhaps the lawn.

Shrubs pruned into unnatural shapes likes these are a sad sight

In reality, we often put up with shrubs that are too big for their space and need to be pruned regularly; that easily get infested with white flies (such as hibiscus), need lots of water, and some of them are plain boring (imagine our ubiquitous Indian Hawthorne hedges).

If your shrubs have this problem or don’t do much screening or don’t provide privacy… Nor provide food for your family and don’t show a real asset to your landscape, perhaps they are next on the to-lose-list?

3. Can you imagine? (removing the lawn)

This turf hasn’t seen kid’s play for years…

Many of our urban lawns don’t deserve having: Nobody is using them really as the children have grown and need much larger spaces. Our pets don’t mind using the mulched areas for their ‘business’…

Turf needs frequent water and maintenance. It dominates the garden scene without ever being visited by hummingbirds, butterflies or other wildlife except for rabbits and the occasional mocking bird.

If you select to let go of the lawn also, and decide to create a more sustainable landscape, the rewards are plenty, as there many options for a more colorful, more interesting landscape with fascinating, drought resistant plants that will excite you year-round.

Tip: Many local water agencies offer rebates for the removal of lawn and the installation of low volume and smart irrigation systems. Check here: TurfReplacement.WaterSmartSD.org

4. Start dreaming

Drought resistant landscaping can be exciting and rewarding year-round.

Aren’t you getting excited yet about the new opportunities for a DIY landscape design that brings year-round fun and color in your garden (and incidentally substantial water savings)?

There are so many xeriscape plants that stay attractive year round even with very little extra water, that are colorful even when not in bloom, that entertain with fantastic shapes and textures, and that bring life and nature to your garden. These plants inspire landscape design ideas that could include a strolling garden instead of a lawn; or, fancy a discovery garden with exotics that only need a fraction of what you applied until now, whether California natives or from other Mediterranean climates.

This is the promise that drought tolerant plants hold. They alone, when chosen for your site and for your soil and microclimate, will not need no or only insignificant amounts of supplemental water.

The following links take you to plant and design discussions, all centered on how-to case studies, or exceptional plant suggestions. Here are a few suggestions of how to go about your design:

You can browse the UC Davis publication “Arboretum All Star Plants” that lists beautiful low-water plants by type and gives names, space and water needs, required exposure, and photos.

Read up on how to use the quiet winter months to prepare for this and next year’s success
The joys of winter – preparing for next year’s success and enjoyment of our drought

A colorful example of a lush xeriscape

In this post I show ways to breathe new life into your landscape design while keeping water conservation in mind. DIY Landscape Design: Breathe New Life into Your Garden

Or read up on the case-study of a transformation of a very traditional, lawn-centered landscape. Sustainable landscape design – celebrating California at its best

If you are looking for exceptional drought resistant / drought tolerant plants following this link. My Favorite Drought-Resistant Plants for Southern California

If you can’t get enough of exotic looking plants that fit well into the xeriscape landscape read this post. The eye-catching bromeliad – No tenderfoot in the drought resistant landscape

In this post I write about more tropical looking plants with exuberant color and tropical appearance without the typical water needs of a tropical plants. Xeriscape Design: Hot and lush yet waterwise – Tropical look-alikes for an arid land (Part II)

How to bring your irrigation system up to the task; the importance of mulching and knowing your soil, selection of materials – all these issues are crucial elements in your efforts towards protecting your landscape from the drought and enjoying it, too. Look for these and more Resources to help you in your work in the second half of this post to be published next month.

The lawn needs to go – but what then? Water Conservation Issues and Garden Re-do addressed at “The Garden”

March 24, 2011 By Christiane Holmquist 1 Comment

Prompted by the rising water cost and irrigation restrictions, San Diego homeowners consult the many resources available the Water Conservation Garden in El Cajon (at www.thegarden.org ). Among these resources are landscape design and horticulture experts offering consultations on subjects like “California Friendly Plants”, watering, arboriculture (the science concerned with trees), construction issues and landscape design. I enjoy being one of those professionals, and I thought you might be curious to learn how such a consultation might work for the people that come there.

In my consultations I generally encounter the same objective: Feeling the need to reduce their water bill or wanting a landscape that is more practical and ecological, these homeowners are ready to retire their mostly lawn-centered landscape. They come to the Water Conservation Garden with the common question, “What do I plant now?” Most of them believe that planting the right plants would make their gardens better and solve their problems; isn’t that what the beautiful low-water-use plants at “The Garden” are all about?

I understand this thinking but, as designer and horticulturist, I don’t think that suggesting different, albeit drought resistant, water-wise or “xeric” plants, would address the underlying problem (although those plants are generally more sustainable). I feel that planting random groups of plants into the former lawn area would not create attractive, comfortable spaces for outdoor living that “work”. Since that is my focus, I explain to the visitors that it would serve them best if they considered first how to make enjoyable outdoor living possible, in separate spaces designed for different uses.

What needs to happen in a yard so it can become an “outdoor living room”? How do you convert it into a play room, or entertainment space, a space to hang out, relax, dream, rejuvenate?

A garden space needs to be organized spatially and hierarchically, and I start my design process, in which I involve my visitors, by asking them if they can think of an activity that they would like to do but never had room for or that was relegated to a back corner of their garden. Perhaps there is some almost forgotten vision of a garden scene in the recesses of their memory that they never took seriously? Take the example of my last visitors at the Garden:

This family, husband, wife and son, arrived well prepared for the consultation, with photos and a sketch of their garden drawn to scale. They had decided to take out most of the lawn, a large expanse right by the patio; they would only keep a small part of it for their son for whom lawn mowing is a therapeutic activity. Opposite the patio, far across the lawn, was a planter bed, but since it was so far away and confined also by a low wall, the flowers in it were not recognizable from the patio. To my surprise, the lady told me that it held roses! Her husband mentioned, almost in passing, that he would like to grow succulents. Some trees were there, but they had been planted around the louter perimeter of the lawn so that they couldn’t throw any shade where it mattered most, which was on their hot south-west facing patio.

“Hardscaping” elements such as patios, walk ways, fencing, arbors, boulders – convey permanence and add structure. Most of them don’t have to be maintained, except for some new coat of paint or occasional sweeping, depending on the material used. And they don’t demand watering, fertilization, pruning… So I suggest to incorporate them as much as possible into a design and let them “furnish” the garden, organize the space into areas of different use, provide separation as well as access, focal points, delineation and definition.

In the case of the before mentioned visitors, we found that a swing for adults, placed under a shade tree, would be lovely to have; I suggested to place it at the far end of the garden from where the family could see house and patio from a new perspective, and I drew its outlines on transparent paper taped over their sketch. And why not pull rose bed and succulents closer to the patio from where they could be seen? Of course not into one flower bed, but in different areas that are perhaps even mounded up, separated by a walk way: Gently curved mounds give movement to an otherwise flat plan, and the plants on them can be seen better, like on a painted canvas. And if your soil drains poorly, creating those mounds helps improve the drainage because you can mix the mounded soil to provide the drainage your plants need, such as many Mediterranean plants, California Natives and succulents, and even roses.

roses framing view

As for the lawn, we drew a much reduced kidney-shaped area that started at one end of the patio, wrapped around behind the rose bed and the succulent mound, and ended at the other end of the patio. This way it was still visible and easy to get to from the patio without dominating the foreground. And to make all the different areas accessible, we discussed stepping stones and DG as possible material for the walkways, even coarse landscape mulch was considered.

Lastly we reviewed the possible locations of trees, and I pointed to my most favorite reference books on this subject: Ornamental Trees for a Mediterranean Climate, the trees of San Diego, by Steve Brigham with book design and photographs by Don Walker, and the Sunset Western Garden Book. Here gardeners can research all their favorite choices before making the final selection; they can actually visit the trees shown in the tree book at their location!

Our time was up, and although we had not talked much about plants in detail, the family was happy (I suggested to look to the Water Conservation Garden’s displays for ideas). Both husband and wife had information and tools in their hands that will make “playing” with their spaces, on paper first, a fun and exciting activity; selecting goals that are realistic and achievable with their budget and energy will now be a manageable task. And finally, armed with the proper reference books and resources that the Water Conservation Garden and other public gardens in San Diego County offer, they will be on their way to a garden that they can enjoy, and live in.

My “Fun-tainer” plants – as seen at the Del Mar Spring Home Garden Show 2011

March 23, 2011 By Christiane Holmquist Leave a Comment

At the heart of my considerations for this container display was my desire to create a composition of beautiful yet tough plants that would delight their owners for a long time without being too fussy or difficult to replicate. They would need to tolerate exposure to drying winds, intense sun, month-long temperatures in the upper nineties or low hundreds and occasional light frost, periodic neglect (and no watering), and a lot of competition for space, both above the soil level as well as for the roots. And they would have to like living in my hypertufa troughs (see my previous post), at least for the next 2 or even 4 seasons, to be “sustainable” (at least as far as a container-existence is concerned).

I already had a few suitable plants: Leucadendron discolor, Aeonium Sunburst, Firecracker Broom, Crown of Thorns, String of Pearls… These are all drought tolerant shrubs, perennials and succulents whose adaptation to prolonged container life on my deck in Ramona I had been admiring for a couple of years. I only needed to find complementary plants that would offset or enhance their qualities and allow me to juxtapose textures, forms and colors.

Although my intended “pièce de résistance”, the Leucadendron discolor, had clearly proved that it can survive a container-existence (mine is now some 6 ft tall and 3 years old) it was too big for my trough. I chose instead a close relative, the Pincushion Yellow Bird, Leucospermum cordifolia ‘Yellow Bird’ that drew lots of admiring comments at the fair. This beautiful South African shrub is related to Proteas and reminds me of the flowers of thistles – without the bristles. Sunset gives the growing zones as 15-17, H1 and 21-24. It grows to 4 ft tall and wide and can take several degrees of frost; the side buds will produce flowers even if the main flower buds freeze.

The nodding Pincushion is the best species for cut flowers with blossom clusters that are about 4 inches across, borne at the branch tips. The bloom peaks in late winter or early spring and can last for 6 months but can start earlier in mild winters. It is supposedly difficult to grow because it needs perfect drainage, protection from drying winds but good air circulation. It requires full sun, regular water only in the beginning until establishment (several months to a year depending on planting season) when it needs water only every 2 to 4 weeks. Selections of this plant in other colors include ‘Flame Spike’ (salmon red) and ‘Red’ (orange red).

Because of the Yellow Bird’s gawky and gangly form I decided to place a “counter weight” next to it, and the appropriate one had to be the Sunburst Aeonium. This succulent grows leaf rosettes at the branch tips that reach a foot across, to form plants that can be about 2 ft across and of about the same height. The fleshy leaves have a delightful variegation that makes the plant very attractive. It blooms after several years only and will then die, but the new “pups” or side shoots will replace the mother plant. With age, these plants become leggy but you can keep them bushy and encourage branching by cutting back branches several inches below rosettes. These cuttings can then be used for easy propagation: let them dry for a couple of days, then set in sandy soil kept barely moist until new grow emerges.

With its low watering requirements and equal sun tolerance it will make a good companion to the Yellow Bird.

Now, on the side of the Protea, I needed something softer, preferably in a complementary color, and draping over the edge of the container. For this I chose Setcreasea pallida (Tradescantia pallida ‘Purpurea’) or Purple Heart (also called Purple Queen): This creeping plant has only moderate water requirements, is tolerant of some frost that might kill the tops but recovery is fast in warm weather. It will reach 1 to 1 ½ ft height and about 1 ft wide, and needs to be pinched back after bloom. The stems tend to flop which makes a good container plant if combined with an upright ‘partner’. (In parts of this county it can be unattractive in winter, but it seems well worth the try.)

In the rear container one you can see the red and purple companions: Crown of Thorns, Coral Fountain (also called Firecracker Broom), Geranium ‘Vancouver Sentenniel’ and Statice. The Firecracker Broom, also aptly called Coral Fountain, is a good container plant: Here it keeps a much neater and smaller form than in the ground where it can reach to 5 ft high and wide; if the green, almost leafless stems of my container get too long they are easily shortened without loosing the graceful drooping form. On my deck in Ramona it has continuously produced a profusion of bright red, narrowly tubular flowers since last year that attract hummingbirds. This shrub needs regular but small applications of fertilizer to keep blooming. It tolerates partial shade or bright indirect light and needs only moderate to regular watering.

Next to it, producing an attractive contrast with its sturdy, upright form I planted Crown of Thorns Euphorbia milii. It, too, hasn’t stopped flowering since I planted it in the previous container about 2 years ago. It doesn’t seem to mind that I uprooted it from its previous home… It’s a bit thorny but can be handled easily with leather gloves that will protect your hands also from the milky sap that can cause skin rashes and is toxic if ingested.

It also requires excellent drainage and has very low water demands. It grows 1 to 4 ft high and about 1 ½ ft wide which makes it an excellent upright narrow accent in a container. Many varieties and hybrids of this one exist in colors of yellow, pink and orange. In windy or frost-prone area it is best grown against a sheltered wall. Salt tolerance makes it ideal for seaside plantings! It tolerates partial shade or full sun, and as indoor plant it needs bright light.

All these plants are set into a fast-draining succulent soil mix. The two troughs, displayed at the fair back to back, are now back at my house and adorn my front door and my deck. I doubt that I will need to keep an eye on them for the last days of “winter” and a possible frost. And for next winter I’ll keep an old bed sheet handy in case a strong frost is in the forecast. From now on my main concern will be not to overwater, and to not forget to feed the plants occasionally, and to keep the ants from raising a colony of aphids on them.

And if you need sources and would like to share your own container-stories with me, please let me know!

Yay! The fountain is in!

February 2, 2011 By Christiane Holmquist 7 Comments

(Cont’d from http://www.cholmquistgardens.com/2010/12/not-your-everyday-fountain/ )

What excitement when the fountain was delivered, after a few weeks of anticipation and faith that the fabricator would “get it” this time. It’s all we had imagined: Gracefully curving, it echoes the lines of the house and is of a material that complements its modern character: Cor-ten steel that is formulated to rust naturally and to provide a garden sculpture that works well in this landscape. Water gently flows over all sides and disappears in the gravel bed underneath (that hides a sub-terranean reservoir from where it is pumped up again).

This low-volume, water-conserving feature provides constant entertainment as the homeowner sees it from her kitchen window, and will be even more attractive to the grandchildren that can step up closely and play with the water (anticipating this we placed a sitting area next to it.)

Nothing of these few words reveal of course some “hick-ups” that the landscape contractor had to overcome first (and that are not un-usual in the landscape field): Tweak the water flow so it sheets evenly over the edges; wait a few days until the water started to clear up after the first rapid rusting which left the water murky. Now the water is almost clear, and in a month or so it should have completely cleared up.

It’s almost perfect: Just wait and see it when all the plants are “in” and also the (low voltage) landscape lights that will illuminate it at night; I think it will be beautiful.

“Trees in my garden?…. No tree, please!”

August 8, 2010 By Christiane Holmquist 2 Comments

Front yard before re-landscaping

I never thought I would have to come to the defense of trees in the landscape. One of the most perplexing moments in my profession happens when a client says that they don’t want trees in their garden. Upon my rather baffled question why, their response is usually “too much water use”, “too much maintenance”, “not needed” or “just too much trouble”.

Hearing this makes me cringe, but I imagine what might have caused their feelings: High maintenance (such as pine needles in their pool filter), nuisance (like olive stains on the pavement), or danger (such as a branch dropping out of a Eucalyptus tree). With these images in mind, trees are for them undesirable members of the plant family that they don’t want in their garden, and they don’t share the notion that “trees are deeply rooted into the human psyche; in a hectic and chaotic world, greenery provides you with a safe, nourishing haven”. (Fran Lambert, Consulting Arborist, in “Trees and Turf”, April 2006).

Front yard after introduction of trees and other colorful plants

I am passionate about good design as well as about plants, so remaining calm in this situation and not becoming “preachy” is a challenge. The role of trees in the landscape seems uncontested, but when you think about them, what comes to your mind besides beauty, shade, stature?

For me as landscape designer, I am foremost interested in the architectural aspects of trees. First of all, their size and mass establish the overall framework of the spatial composition; in this way, they are among the most important landscape design elements, creating floor, walls and ceilings of “outdoor rooms”. A vegetative ceiling can provide a sense of vertical scale in an outdoor space, a feeling of comfort and shade.

Trees give a house scale and place it in proportion with its surrounding; a house without trees therefore feels like a box that isn’t grounded, like a container that hasn’t settled into its site.

Back side view of house with tree

Back yard without trees

Trees can act as windbreaks or screen of an unsightly view, or frame an attractive one like a picture frame. With their color and structure, they can be used as an accent point in your landscape picture.

Besides being indispensable parts of a design, trees play a great role in human as well as the environment’s health: Their canopies contribute to air quality by filtering dust; they also provide some noise reduction (the tall, densely planted trees with fleshy broad leaves do the best job). And, as a tree provides nesting and shelter for birds, they assist in insect control, and listening to the song of birds is usually very pleasant.

Shady pond

As energy consumer I consider also the energy savings through trees, and last but not last SHADE! “It never rains in California”, and the whole world envies us for it, but to have endless sunshine in a garden would be like living on a sunny plaza that has no shelter from the sun. A man-made shade structure can be a great element in a landscape, but it doesn’t quite have the same effect as the dappled, cool and moist shade of a tree! Summer shade from the deciduous trees placed on either south or west sides can lower utility cost by amazing 10-15% (and allow for solar heating in the winter months).

These are measurable benefits that we gain from trees (not to mention the delight that a tree in full bloom can create). And the cost of trees, you may ask? Of course, there is some maintenance: A young tree will benefit from yearly inspections and minor corrective pruning during its infancy to assist it in growing into a well-shaped healthy specimen; this way a costly restorative pruning can be avoided when the tree is much older.

And water needs? Of course you will need to water your trees; even trees indigenous to our dry Southern California need water during their establishment phase which can last a couple to 3 years depending on the amount of rain during the winter months and other factors influencing establishment.

Weighing the investment in trees against their benefits, consider this: The National Arbor Day Foundation states that “A well placed and properly irrigated tree will have a measurable return on investment”: In deed, the Foundation estimates the value that trees add to properties at 15-20%!

In order to assure the most pleasure out of your trees and the least trouble, here are some suggestions how to avoid problems with your trees:

Select trees that:

– are in the most natural state as possible and have a good trunk taper

– have juvenile branches spaced throughout the trunk (until trees are anchored and established, lower juvenile branches need to remain on the trunk and main stem and therefore looks more like a shrub)

– are appropriately sized for the container

– have branches with wide angles of attachment (larger than 45 degrees)

Avoid trees that

– have been pruned into a lollipop shape

– are supported by a nursery stake (whenever possible)

– have pot-bound or girdled roots

– appear weak, sick, or unhealthy

– show mechanical damage or other wounds

And don’t plant trees too close to power lines, nor closer than 10 ft to permanent structures. (Check also on proper guide lines for tree planting in fire-prone areas).

There are great resources in our County for people that want to learn more about trees: The book “Ornamental Trees for Mediterranean Climates; the trees of San Diego” is a colorful guide and compendium of a host of trees that thrive here, with descriptions, photos, and even addresses where the photos were taken. The Water Conservation Garden in El Cajon (more info at www.thegarden.org ) showcases many suitable and lovely trees for our area. And of course there is Balboa Park with its trees, and the San Diego Botanic Garden (formerly Quail Gardens at www.qbgardens.com ).

I don’t think I’ll ever be detached and impartial when it comes to trees, but armed with the above list of arguments and paybacks I hope to be more neutral and professional when explaining how trees will benefit my clients and how fundamental (could you say imperative?) they are for their home landscape. Despite of their initial rejection none of my clients has yet refused to concede interest in trees, and fortunately, I haven’t yet had the commission to design a “tree-free” garden. That would be the saddest thing, and I hope it will never happen.

FIRE-UP YOUR PASSION – Red plant accents that warm up your landscape

April 14, 2010 By Christiane Holmquist 2 Comments

Mass-plantings of Crown-of-Thorns Euphorbia milii

I have a special predilection for the color Red: Not only does it become me as a blonde, it also fires up my mood, makes me cheerful and revs up my energy. I am drawn to Red like a hummingbird, and if Red on me invigorates me, I believe seeing red “lights” in the garden would do the same. Even in a garden space where the main hues are cooler and more restraint, and where there are lots of calmer tones in rocks, timber, pathways and other hardscape elements, a few red splashes warm up the planting scheme and make the tones more saturated. Red works particularly well in South-West style gardens, where it makes a lively contrast to lighter colors such as DG, sand or gravel whose tones look washed out in the strong sunlight; used as color on a background wall it adds drama to succulents and cacti.

Bloodred Trumpet Vine Distictis buccinatoria

Red can provide a bright focal point, such as a Bloodred Trumpet Vine Distictis buccinatoria drooping from a wall or from an arbor, or a Crown-of-Thorns Euphorbia milii, mixed with Firecracker Broom Russelia equisitiformis, spilling from an urn. Used as accent plant in the background, such as in groupings of red-flowering Aloe behind shorter, softer perennials or clumping succulents, the Aloe’s red flower spikes will show like exclamation points, and their pointy leaves will create a dynamic contrast in structure and texture.

Firecracker Broom, Crown-of-Thorns and Kalanchoe manganii in container

When planted in the foreground as border accent, or hugging the curves of a path, Red creates a bright ribbon through the garden that your eye can follow; as foreground plant repeated throughout the garden it ties different areas together and adds cohesion.

If used as red winter bloomer, f.e. Cyclamen Cyclamen persicum, it will bring much needed warmth into your planter beds, and in dark and shady places the red flowers will shine like lights.

Delightful summer-blooming Cantua 'Hot Pants'

I am having fun doing this and have compiled lists of plants with red flowers that I like to use. Of course each landscape prompts a different choice because of its design style, its existing sun/shade conditions, its soil type, the character of the architecture and the hardscape materials chosen. The following compilation of “Reds” contains plants with various growing conditions, but all are long-lived, low in maintenance needs and more or less water-wise and tolerant of xeric conditions. (However, it’s important to note that a plant’s location will determine how tolerant of dry conditions it is: For example, a Crangrape Cuphea C. llavea “Crangrape” is more drought tolerant in coastal locations and soils than in hotter inland valleys.) Nor is the list all-inclusive, and if you have more suggestions, I will be happy to add them.

THE SHORT & MEDIUM STUFF FOR SUN & PARTIAL SHADE

Aloes (many): Aloe ‘rookappie’, Aloe saponaria, Aloe arborescens, Aloe nobilis
Autumn Sage & relative Dwarf Crayon Sage Salvia greggii, S. grahamii
Baja Fairy Duster Calliandra californica & Fairy Duster Calliandra erophylla
Blanket Flower Gaillardia grandiflora
Bottlebrush Callistemon citrinus and C. viminalis
Butterfly Weed Asclepias tuberosa
Cantua ‘Hot Pants’ Cantua buxifolia
Chuparosa Justicia californica
Coral Bells Heuchera sanguinea, Heuchera micrantha
Croscosmia
Crown-of-Thorns Euphorbia millii
Emu Bush ‘Valentine’ Eremophila species ‘Valentine’
Royal Beard Tongue Penstemon spectabilis
Firecracker Penstemon Penstemon eatonii

Grevilleas ‘Poorinda Constance” , Grevillea lanigera
Kalanchoe Kalanchoe blossfeldiana & Kalanchoe manganii
Kangaroo Paw “Bush Blaze” & “Sunset”, Anigozanthus flavidus
Many Daylilies: Red Hot Poker, Cardinal Spokes Hemerocallis hybrids
Nodding Pincushion Leucospermum cordifolium
Propeller Plant Crassula falcata
Red Hot Poker Plant Kniphophia uvaria
Sticks on Fire Euphorbia tirucalli
Watsonia Watsonia intermedia
Zonal Geranium Pelargonium hortorum

(See also my previous article “Exceptional Winter Blooming Plants for Southern California”)

RED-FLOWERING TREES
Here only an incomplete list:
Australian Flame Tree Brachychiton acerifolius
Coral Trees Erythrina x bidwillii, E. caffra, E. coralloides etc.
Crape Myrtle “Watermelon Red” and “Tonto” Lagerstroemia indica & Lagerstroemia x hybrids
Firewheel Tree Stenocarpus sinuatus
Mimosa, Silk Tree Albizia julibrissin

Exceptional Winter Bloomers For Drought Resistant Landscaping in Southern California

December 2, 2009 By Christiane Holmquist 1 Comment

Our first winter rains have blown through and and brought a welcome refreshment after the long and hot months. As our summer bloomers are going into their winter rest, much of our traditional drought resistant landscaping is beginning to look a bit drab (unless you have one of those ever-bloomers such as Bougainvillea). The approaching holidays are creating an atmosphere of hope and expectation, and when we add to this the notion that this is an ideal time for planting in the low water landscape, we find ourselves searching the garden centers for the colorful plants that can cheer up our winter gardens. However, you’ll notice that most nurseries reserve the bulk of their space for the big sellers: Poinsettias, green wreaths, Camellias and Azaleas of course, and many winter blooming annuals. If you are more interested in exceptional xeriscape plants that don’t have to be replaced at every change of the season, that will flower through the winter months and that will add color to your garden for many years to come, read on. From the many that come to mind I have chosen a few that are un-demanding in maintenance, low in watering needs, and just outstanding plants. This list is just a first selection, and I’ll be happy to share many more with you if you contact me.

THE SHORT STUFF: xeriscape plants at around a foot height

Santa Barbara Daisy Erigeron karvinskianus, is a free-blooming perennial with dainty, white/pink daisy-like flowers to ¼ inch wide and narrow leaves to 1 inch long, that gracefully trails and slowly spreads to about 3 ft with a height of 10 to 20 inches. It’s not really a winter bloomer as it has already been in bloom all summer long, but the flowers never stop coming. It likes full sun but can tolerate partial shade and is very drought tolerant. It can be a bit invasive but is not overwhelming. Use it for edgings, as groundcover, in containers and in rock gardens, in naturalized beds, hanging baskets or in dry laid walls, especially to offset plants with a coarser texture, such as fleshy Ghost Plant (see it described in “‘The “work horses” in my drought resistant landscaping”).

Sundrops and Trailing Buttercups Calylophus drummondii & Calylophus hartwegii

These closely related perennials grow to about 1 ft high by 2 ft wide. Although not true winter bloomers, they will, if planted in a sheltered spot, continue their bloom from summer to winter, although a little more sparsely. I love them because they are long flowering must-haves for the xeriscape, undemanding in maintenance. Sheer them down to a few inches in mid spring to give them a rest and tidy them up for the next flowering season. Their brightly yellow flowers will cheer up many drab spots in your garden, in full sun or light shade, and their fine textured foliage is an excellent companion to coarser textured succulents.

WINTER-BLOOMING DESERT PLANT SPECIES

Baja Fairy Duster Calliandra californica: This native to Baja California and Sonora, Mexico, is an evergreen shrub with an open growth that can reach 5 ft to 5-6 f wide. This species is sometimes compared to Fairy Duster Calliandra eriopylla, which is smaller (to 3 ft x 3-4 ft wide), summer deciduous to evergreen, with less luxuriant foliage. There is also a hybrid available called ‘Maricopa Red’. These sturdy yet fine-textured shrubs like hot dry situations, although the Fairy Duster C. eriophylla can also tolerate the warmer coastal environments. They all like the full sun and need good drainage. With little to moderate water the Baja Fairy Duster C. californica and its cousin ‘Maricopa Red’ bloom year round; Fairy Duster C. eriophylla starts in late winter and goes into early summer, but leaves and bloom last longer if some summer water is given (the Fairy Duster is summer-deciduous). All produce the characteristic exotic duster-like flowers that are puff balls of deep red or light to deep pink stamens (C. Eriophylla) ½ to ¾ inch in size that are irresistible to hummingbirds.

Baja Fairy Dusters C. californica produce flattened seed pods 2-3 inches long and dark brown; those of Fairy Duster C. eriophylla are quite attractive: to about 2 inches long, brown with red margins and a fuzzy coating that catches the sunlight. This one can be used for erosion control as it spreads by rhizomes.

These shrubs work well in the low water landscape as accent or massed as groundcovers (especially the smaller C. eriophylla). Try setting off their fine textured foliage next to more sturdy succulents or cacti to lend them a softening effect; The Fairy Duster C. eriophylla also makes a great specimen in a glazed container.

Feathery Cassia (also called “Old Man Senna”) Senna artemisioides (sometimes sold as Cassia artemisoides). This Native to Australia has silvery-grey, needle-like foliage and is 3 to 5 ft tall and wide with an airy open structure. It can take full sun or partial shade and likes well draining soil. Beginning in late fall, it covers itself with a profusion of yellow ¾ inch clusters of 5 to 8 flowers puff balls of flowers that can continue into early summer when the shrub takes a rest, to start again in late fall. Its reddish-brown flattened, 1½ inch long narrow seedpods hang on for a long period of time, but in the heat of summer this provides an attractive contrast to the silvery foliage. It is very drought tolerant but looks best with moderate to regular water.

Grevillea ‘Poorinda Constance’

Grevilleas are evergreen shrubs and trees most of which come to us from Australia. Of the many that we can grow in our County this one displays an open, graceful growth and can reach 8 ft tall by 12 ft wide. Its needle-like, deep green 1 inch long leaves are almost white beneath. The shrub produces clusters of orange-red flowers in winter and spring and intermittently at other times. It needs full sun or partial shade and little or no water. As a spectacular screening or specimen shrub it will mask unsightly views or provide privacy.

WINTER-BLOOMING SUCCULENTS

Aloe Aloe arborescens

The Aloes are primarily South African natives that range in size from 6 inch to tree-like, but all form rosettes of fleshy, pointed leaves. To me, this is the most striking and imposing Aloe as it forms a large, rounded shrub-colony that over the years can reach 10 ft high and wide. Branching stems carry big clumps of grey-green, spiny-edged leaves. Is is easy to grow in well-drained soil, can take full sun or shade and salt spray, needs little water but can take more. This makes them nice companions to perennials that have similar water- and drainage needs. Its foliage can be damaged at 27 F but will in most cases rebound. In winter, this plant produces spiky torch-like clusters of bright brick-red flowers. A variegated form is also available.

Cotyledon Cotyledon orbiculata

This south African native can quickly reach 2 ft tall, about 2 ft wide. Its fleshy paddle leaves may be green edged with red or whitish-gray, depending on variety; its sports drooping orange-red bell-shaped flowers from late fall into spring. This succulent is suitable for the drought resistant landscaping and needs excellent drainage. Tolerant of light frosts, it is easy to propagate from cuttings and makes a great container plant.

WINTER-BLOOMING, DROUGHT TOLERANT TREES

Pearl Acacia (also called Queensland Silver Wattle) Acacia podalyriifolia. Native to Australia, Mexico or the southwestern US, many attractive, winter-blooming and fragrant Acacias are available to us. The evergreen Pearl Acacia grows to 10-20 ft tall and 12-15’ wide with roundish, 1 1/2 inch long silvery gray satiny leaves. It is a shrubby plant that can be trained into a small tree. Brilliant bright yellow puffy and sweetly fragrant flowers are produced in late winter/early spring. It is tolerant of our soils and needs full sun little or no water. The Sunset Western Garden Book recommends to prune the Acacias that are grown as tree form to open up their interiors which will reduce dieback of shaded branches.

Sky Flower Duranta erecta (D. repens, D. plumieri)

This is a fast growing evergreen shrub that can be easily be trained into a small tree. It grows 10-25 ft tall and 6-10 ft wide. Especially as a multi-trunked plant it can make a beautiful specimen for the low water landscape. Its glossy green leaves are about 2 inch long on broadly arching branches that may or may not have spines. Pretty ½ inch sized violet-blue flowers in fragrant clusters are produced nearly all year and attract people, butterflies and hummingbirds. They are followed by pretty yellow berries (toxic if ingested). It grows easily in most soils in full sun or partial shade, needs only average watering and tolerates temperatures down to around 20 F.

There are also light-blue and dark-blue flowered selections of this shrub available, as well as a white one called ‘Alba’. ‘Sweet Memory’ is thornless, with flower petals edged in white. ‘Gold Mound’ is a small one, only 1 ½ ft wide and high, has brilliant gold leaves and flowers rarely, but it is excellent for adding color to container plantings.

SUPPLIERS & RESOURCES
Waterwise Botanicals a few miles north of Escondido grow exceptional xeriscape plants, including perennials, shrubs, succulents, cacti and roses. Their availability list with photos and plant descriptions is online.

Briggs Tree Company in Vista carries a wide variety of traditional landscape as well as drought resistant plants, and their list (most plants now with descriptions) is available online.

Green Meadow Growers in Bonsall also offer a great line of grasses and succulents as well as shrubs and perennials; they also make available plants from Mountain States Wholesale Nurseries who specialize in desert plant species.

Oasis Water Efficient Gardens in Escondido offer an exciting range of succulents, cacti and other low water landscape plants.

Great photos, ideas and tips for designing with succulents are presented by renowned author and photo journalist Debra Lee Baldwin, Her book ‘Designing with Succulents’ has been a wonderful resource in my design work, and I look forward to her next book, ‘Succulent Container Gardens’ that will appear shortly.

Soil Probe and Mulch – Two essential tools to help you conserve water and keep your landscape healthy

September 24, 2009 By Christiane Holmquist Leave a Comment

water feature pond and sage appeal to hot gardens

I am fortunate that I can experiment to some extent in my own garden with layouts and plants touted “drought tolerant” and “water wise”, and that I can practice the techniques of planting, maintenance and water conservation that I explain to my clients.

Plants have always been my passion, but in our hot inland valley during the long hot summer months and no rain in sight until late November or December, and with fast draining DG soil (decomposed granite), proper watering becomes important, and determining the right irrigation amount, frequency and duration is an on-going task.

In the past years our reservoirs have emptied to very low levels and water prices have shot up. First I learned to recognize drought stress, and then it became obvious that my planting design needed to become more sustainable: I had too many plants with greater water needs than I felt was warranted, and the remaining ones were too close together, requiring more water and more maintenance to remain tidy. Out came many popular plants, such as as Garden Penstemon, Kangaroo Paw and Lamb’s Ears, and most of my roses were sacrificed as well (I’m down to one that can do with less water – the climber Mermaid).

Although it may sound like a painful sacrifice, it was not: On the way to that easier-to-maintain and less thirsty garden I am discovering many beautiful plants that are doing very well here, like Flannelbush or Mountain Lilac from California, Proteas from South Africa, Texax Ranger from the Southwest and Northern Mexico, succulents from South Africa or California itself … the list is long and exciting, and I will be writing in more detail about some of these exceptional plants in future posts.

Here are some tips and techniques to keep the ornamentals and the vegetables in your garden healthy and good looking through these hot months:

Lots of mulch: I try to keep the layer at least 3 inches thick, on top of the soil around trees and shrubs and in between my perennials; even in my vegetable garden I try to apply it where possible. I prefer a medium textured bark or similar mulch with pieces of about one-inch in size; this will allow water to pass quickly through the mulch into the soil instead of being retained by the mulch. My irrigation system applies water infrequently and deeply; this keeps the mulch dry and optimizes its water-saving potential. Every year I replenish a good inch of this layer as it decomposes slowly, enriching my soil.

Mulch is probably being put to good use in your garden, too: The multiple benefits of this material can hardly be gained otherwise. But you might have some areas where mulch is difficult to apply, as in a vegetable garden. Here shallow cultivation between watering cycles, with a hoe to 2-3” deep, loosens the soil, destroys weeds, aerates the roots and assists in reducing water needs. (Be careful not to injure delicate surface roots around tomatoes and corn.)

My most practical, diagnostic gardening tool is a soil moisture probe: This is a stainless steel tube, about 24 inches long, fitted to a comfortable T-handle. When pushed into the soil and pulled out again, a partial cut-out in the long end of the tube lets me check the plug of soil in the tube: I can see how deeply my watering has penetrated, or how much remaining moisture is in the soil if I am unsure whether it’s time to water again. It also allows me to see how deep the roots have grown and, subsequently, how far down my watering should penetrate. If I suspect a disease, such as a fungus rot, the roots in the soil plug tell me how healthy they are by their looks and feel: If they are grayish, soft and mushy, they are ‘sick’ and unable to perform their job. The smell test is important, too: a healthy soil has a good earthy smell, so if that’s off I know that a soil-borne disease is troubling my plant, or that the roots have died because of too much water.

In my landscape design work and horticultural consultations, too, this probe is invaluable: Together with a drainage test it helps me determine my client’s soil type and guides my selection of the plants that will grow in this soil (usually we send a soil sample to a spealized laboratory to be analyzed for its texture and nutrient content). This tube is well worth its cost of around $65 (check with the irrigation and landscape supplier Hydro-Scape, 5805 Kearny Villa Rd, San Diego at http://www.hydroscape.com/ )

Christiane Holmquist Landscape Design. [P] 760-586-6065

Here’s what you can do to protect your landscape during San Diego’s drought and to do it in style, incidentally.

Xeriscape – the technique to garden sustainably and colorfully in a dry climate

Christiane Holmquist

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