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).
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.
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.
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.