xeriscape design 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.

Looking for new landscape design ideas for your backyard? What about a pond?

March 1, 2012 By Christiane Homquist 9 Comments

One of my very first backyard landscape design projects was a small urban backyard renovation where the homeowners were tired of lawn and old shrubs. Ryan and Jill were dreaming of a much more peaceful, enchanting scene and asked me to design a pond that they could view from their deck.

The sound of water running in a small creek from a small rocky “outcropping” and mound in a far corner of the garden into the pond, and a dense leafy screen surrounding the garden would make the backyard very private and block out most of the city noises.

The design was installed some 8 years ago, and I recently went back to visit and to see how pond, fish and homeowners were doing.

I did arrive with some trepidations: My original choice of screening trees had not been the happiest: The Brazilian Tipuana tipu is a beautiful tree with lacey foliage and a wide, umbrella-like crown. It fits well into a low water landscape, is ‘green’ through our Southern California winter but starts shedding its foliage when most other deciduous trees have leafed out already. This takes several weeks until, in early summer, it bursts into the prettiest bloom of orange-yellow Sweet Pea-like flowers. Besides the leave drop problem I had expected that the trees in this xeriscape design would crowd each other out eventually, and I was expecting that the homeowner might regret that selection.

I was thrilled to see a scene not much changed since the garden had been installed: The creek was still running to the pond, providing needed oxygen and delighting us with its gurgling and bubbling sounds. Some twelve smallish Koi were busily milling close to the deck as the evening was approaching, to receive their daily feeding. The peaceful mood was still there as were the trees, although the homeowner said he would remove them soon because he intended to install solar panels on his roof. To my relief he said that he had loved their look and therefore didn’t mind the extra maintenance. I asked him about his maintenance program, and he explained that he adds a biological clarifier on a weekly basis, and an algaecide as needed (both are biological controls). He also uses a skimmer and filter cloth, hidden under a fake rock, that get cleaned weekly (except during heavy drop like the Tipus drop their leaves); then there’s a biofall (where the waterfall starts) in another plastic box that has the same filter mesh at the bottom and 2 mesh bags of rock. The leaves and petals are not too bad, he says – even when the wind has blown an extra load of petals into the water.

What about “visitors”? He has created some hollow spaces at the bottom of the pond under several overturned clay tiles where the fish hide when an occasional heron or egret comes to visit. Raccoons merely push a few of the smaller rocks around in their attempt to catch a Koi, but always give up – they don’t like the deep in the middle of the pond where the fish hide.

Over the years Ryan and Jill have enjoyed their water feature that always entertains them with a lively yet peaceful scenery: There are rocks and boulders, rushes and grasses at the water’s edge, and there’s the cherished Pineapple Guava that has grown into a graceful large shrub, on the other side of the pond.

There’s the play of sunlight on the water’s surface and the steady darting of dragon flies or other beneficial insects that land on blades and pads of Iris and Water Lilies. Birds of course come to the water’s edge to bathe and drink as well as other critters. Visitors come to stay, such as frogs, others wonder out again, such as the occasional raccoon.. There’s the comfortable chair across from the deck inviting to sit and watch the activities at the pond from a different angle, especially the perennial glint and splash of the Koi fish. There are lots of babies at this time – they are the babies that hatched in early summer of last year.

I’m not an expert in pond building or maintenance, so here’s a quick overview (and I don’t claim completeness):

The prominent ingredients of a fish pond are water, plants, fish, snails, soil, light, temperature – and time. After all the ingredients have been put together, it takes time for all to balance out and grow into a clear pond.

Algae, while they are unsightly, may not necessarily be unhealthy; they can make the water appear brownish or green, or grow as fine threads or moss-like coverings on shells, snails, walls and stones. Small fish can feed on some of these algae… Threadlike algae are often associated with crystal clear water and are evidence of the oxygen-generating ability of algae. A lot of things feed plants, algae and fish: Food that we give the fish; foliage that drops into the water and decays; and the waste that fish produce.

Adding aquatic plants to a pond not only increases its visual appeal and natural look; floaters such as Water Hyacinth , marginals such as Water Iris , and Water Lilies help reduce algae as they feed on nutrients or block out sunlight – both will starve the algae. Shading the water with leaves keeps the water cooler which is desirable. Chemical control may also be used if necessary, however great care must be taken to select chemicals safe for fish and plant life. As the pond matures, the need for chemicals should diminish. Keeping decomposing material in the water to a minimum will also lower the nutrients in the water, less food will then be available for the algae to feed upon. Prune off old leaves and skim the surface for fallen leaves.

The pH of the water can also affect pond balance, and there are formulas suggested to help achieve it. Also, you can determine the most balanced amount of fish and plants for your pond by calculating the water’s volume and surface area.

I’m not an expert in pond matters; I’d rather refer to an ‘ocean’ of information and helpful videos online… You can contact the local chapter of the California Landscape Contractors Association to refer you to a San Diego landscaper experienced in pond building.

And mosquitoes?

Did you know that fish eat mosquito larvae and that mosquitoes don’t like moving water? Keeping your water moving and cleaning off debris regularly that provides hiding places for mosquitoes is a good recipe to control mosquitoes.

What not to love about a pond! I myself have one, as part of my front yard landscape design, by my front door. I watch it from my living room window, and although its location isn’t perfect either (the previous owners must have decided to live with the maintenance; they created the pond at the edge of an oak canopy), it’s a most cherished delight of my garden.

Essentials for the scented winter garden in Southern California

February 18, 2011 By Christiane Holmquist Leave a Comment

When I got home last night in the rain, I took in the air in deep breaths: Such a wonderful smell of wet soil and decaying leaves mixed with something sweet and flowery – where was this powerful scent coming from? So I put on my boots, took a flash light and went into the garden.

I got my face wet as I poked my nose into foliage and flowers of shrubs, perennials and succulents, and not far from my front door I found the first: A grouping of Cleveland Sages Salvia clevelandii that had just opened their buds. These California natives are known for their incredible fragrance, and for those who have never seen or smelled any, the description alone should make your mouth water: This is an evergreen shrub of the mint family with a refined, rounded and arching form, to 3 to 5 ft tall and wide and wider for some cultivars. It has wrinkled, toothed gray-green or dark green leaves that can be used in teas or as substitute for culinary sage and that are deliciously fragrant; a breeze blowing through your garden will take the sweet fragrance far. The flowers are an inch-long, pale lavender or violet-blue, arranged in whorls along the stems, and they are also fragrant. To encourage re-bloom you will need to cut back these flower spikes back, but the shrub is also attractive with its dried flower spikes.

This plant is so popular that several hybrids have been created: Mine is the ‘Allen Chickering’ which gets to 4 ft tall but spreads out to about 6 ft and sports pale purple flowers. Check out also ‘Winifred Gilman’ with lavender-blue-purple flowers, or ‘Aromas’ with gray-green foliage and deep lavender flowers, ’Pozo Blue’ that is hardier than Alan Chickering’ (to 10 degrees F).

The Cleveland sages need sun (partial sun only in the hottest, driest regions), fast-draining soil, and are drought tolerant although they can tolerate occasional watering. There are differences in their cold tolerances that could be important for your location; please check with the growers below for the appropriate one.

A little deeper in my garden the beam of my flashlight hit a tall lanky shrub whose buds were just opening, and I know it carries its name Mountain Lilac for a good reason: The flowers look like miniature Lilac clusters, and to me even their smell reminds me of true Lilac. Mine is the hybrid ‘Ray Hartman’ which is the best known and most commonly grown of the bigger ceanothus hybrids that can reach 18 feet in height and width; its rose-colored buds open to display profuse clusters of sky blue flowers.

California’s Mediterranean climate supports 60 species and varieties of ceanothus, and the choices can be confusing. They grow in some of California’s harshest habitats, ranging from wind-buffeted coastal headlands to dry, exposed slopes at the edge of the Mojave Desert. They come in various forms, from creeping to large shrubs and small trees, and their colors range from bluish whites and pale purples to deep Gentian blue and purple. Most grow in areas that experience an extended summer drought; they tolerate a range of soil types but often are located on steep slopes in well-drained soils of low or marginal fertility. Most then require excellent drainage, but some can also tolerate heavy soil and summer water.

Ceanothus have become popular shrubs in Europe, where cultivation of ceanothus species for horticultural purposes began as early as 1713! Check with one of the growers mentioned below for the species that will perform best in your garden so that its growing conditions match or approach those found in its provenance.

Not far from my backdoor (and closer to the kitchen) I found Rosemary, a true Mediterranean whose name means “dew of the sea”, reminding us of the plant’s native habitat on seaside cliffs in the Mediterranean region. This winter bloomer is not quite as fragrant as my sages but also definitely desirable. The evergreen shrub is covered with narrow, resinous dark green leaves, and through winter and spring its fragrant pale blue to deep violet flowers are a magnet for bees and small birds looking for tiny spiders and insects in the tightly packed flowers (and perhaps also eat the petals).

I love the ‘official’ Rosemary (Rosmarinus officinalis) with its upright habit and somewhat twisted branches reaching for the sky (height typically 4-6 ft and more, especially ‘Blue Spires’). I use its stems for bouquets and the leaves for cooking; even the fragrant flowers are edible.

As with many popular plants, there are too many cultivars and hybrids available to mention here. Of great importance are the prostrate ground-hugging kinds whose heights range from 1 ft to 6 ft or more that are often used in erosion control or as groundcovers.

The toughness of Rosemary is admirable: It’s tolerant of moderate watering, sea-side conditions and blistering sun; I think it’s a must-have in the Mediterranean garden. Although it can take alkaline soil if given a moderate feeding from time to time, good drainage is essential; you can lighten heavy soil with plenty of organic matter. Their cold-hardiness varies depending on selection.

All of these specimens are excellent examples of low water-use, low maintenance, beneficial plants that I love to use in water-wise landscape designs; I think they belong to the category of plants that are indispensible when the design wants to be ‘sustainable’, and with these attributes and their famous fragrance who could resist?

For California natives plants in San Diego County, check out these growers:

Las Pilitas Nursery, in Escondido, at http://www.laspilitas.com/

Moosa Creek Nursery, in Valley Center, at http://www.moosacreeknursery.com/

Recon Environmental Inc., in San Diego, at http://www.recon-us.com/

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

Latest Articles

Connect with me