If you can only plant one thing, plant a tree

White oak. Photo by Henry Domke, http://henrydomke.com

White oak. Photo by Henry Domke, henrydomke.com

The best friend of earth of man is the tree.  When we use the tree respectfully and economically, we have one of the greatest resources on the earth.
–   Frank Lloyd Wright

Let’s say you are designing a healing garden – for a client or yourself – and you only have 10 square feet of planting space. You could plant a few shrubs, or a few more perennials, or a bunch of annuals. Or you could plant a tree. If there’s enough vertical space, and there usually is, go for the tree. Why? Here are some reasons:

Shade is one of the most important components of any therapeutic landscape, and yet it is overlooked so often that sometimes I just want to cry. I’ve seen countless designs that might be successful if enough shade were provided for people to actually enjoy the garden even on hot, sunny days. I’m going to do a whole post on this soon, but I’ll point out a couple key things here. Especially in the healthcare setting, shade is crucial. Many people are “photosensitive” – sensitive to sun and bright light, either because of their condition or from the medication that they’re on. Imagine a garden in a cancer center without shade. I’ve seen those! If you include trees in your design, make sure they are big enough when they go in to provide shade right away. See that mother who is visiting her sick child and wants to sit with him under a nice, shady tree for a few minutes? Look her in the eye and tell her to come back in five years when the tree will be big enough to provide adequate shade. Or plant a big tree and watch as people gravitate to and gather under its soothing, protective boughs. Speaking of which…

You can’t beat trees for symbolism. They are so strong and resilient, and yet so graceful, flexible, and nurturing. And they can live for hundreds of years. Pretty inspiring. Furthermore, lots of trees are used for medicinal purposes. Even if a willow isn’t actually harvested for its analgesic properties, it can still be a good symbol of pain relief in a setting where healing is the goal.

Alone with myself
The trees bend to caress me
The shade hugs my heart.
~Candy Polgar

Sensory engagement
Sight is the most obvious sense, and we can appreciate a tree from a distance, from below looking up at the leaves and the patterns of light filtered through them, from above looking down through a window onto green rather than brown or grey. Remember Roger Ulrich’s seminal study* of patients recovering from surgery? The view that the patients had who recovered faster and needed pain medication was of a grove of trees. Movement is also important – it’s one of the things that attracts our eye and assures us that we’re looking at something real, not just a picture. And it clues us in on another element of nature – air. Is it a still day? Is it breezy, windy? A tree can probably answer your question before you step out the door. Sound: If you’ve ever been in a grove of aspens, or a forest of pines, when the breeze stirs through the leaves, you know how magical the sound of trees can be. Scent: Right now, a Styrax japonica is blooming in my garden, and I don’t want to be anywhere else but outside, inhaling its perfume. Even in New York City, one realizes at this time of year why honey locusts have that name. And finally, taste: How wonderful to have a garden where people can pick and eat the fruit! In June in my garden, the serviceberries ripen and all my friends’ kids beg their parents to let them come pick and eat the fruit. It’s a race between the children and the birds, who also come to visit and harvest. What a gorgeous combination. Which brings me to my next point:

Trees provide habitat for all kinds of wildlife. One of the things that people love about gardens, in addition to the way they look, is the sound. And one of the easiest ways to bring nature sounds into the garden is by inviting birds. And birds love trees.

Seasonal Interest
My favorite trees, especially for small spaces, are the “multi-taskers.” While providing shade, habitat, and other things we’ve touched on, they also offer seasonal interest for year-round enjoyment. Even on days when it’s too hot or cold or wet to go outside, we can usually still enjoy a tree from indoors. A dogwood, for example, blooms in the spring; has green, lustrous foliage in the summer; turns deep red and produces bright red berries in the fall, which then provide food in the winter for birds. Not bad for one tree.

Trees improve quality of life in so many ways
Frances Kuo and others at the Landscape and Human Health Laboratory, University of Illinois at Champagne-Urbana, have been documenting the importance of nature in the built environment, especially in urban areas with high crime rates. Again and again, they have found that the greener the surroundings, the healthier, happier, and safer the people are who live there. And much of this green comes from trees. Go the the bottom of this post for full citations. All of these papers can be accessed from the LHHL website.

Chicago Botanic Garden. Photo by Naomi Sachs

Chicago Botanic Garden. Photo by Naomi Sachs

Truly green
In both senses of the word. Some stats from Trees Are Good:

  • A single tree produces about 260 lbs of oxygen a year. One tree can absorb as much carbon in a year as a car produces while driving 26,000 miles, and two mature trees can supply enough oxygen annually to support a family of four.
  • Over the course of its life, a single tree can absorb one ton of carbon dioxide.
  • The shade and wind buffering provided by trees reduces annual heating and cooling costs by 2.1 billion dollars.

For more information, see an earlier post, Planting the Healing Garden: Trees, Please!

Another great thing about trees? With a few exceptions, you can still plant perennials, grasses, or annuals underneath. Talk about bang for your buck!

To get started: When you join the Arbor Day Foundation (no, I’m not getting any kickbacks), you get a gift of either 10 free trees or 10 trees planted in your honor.

What do you think? If you had 10 square feet of planting space, would you plant a tree? What are your favorite small-space trees, and where have you seen them used to great effect? Leave a comment and let’s talk!

Citations. One-sentence summaries of LHHL articles are in bold.

Adding Trees Makes Life More Manageable: Trees ease poverty’s burden in inner city neighborhoods: Kuo, F.E. (2001). “Coping with poverty: Impacts of environment and attention in the inner city.” Environment & Behavior, 33(1), 5-34.

Views of Greenery Help Girls Succeed: Girls with a home view of nature score higher on tests of concentration and self-discipline. Faber Taylor, A., Kuo, F.E., & Sullivan, W.C. (2002). “Views of Nature and Self-Discipline: Evidence from Inner City Children.” Journal of Environmental Psychology, 22, 49-63.

Vegetation May Cut Crime in the Inner City: In an inner city neighborhood, the greener the residence, the lower the crime rate. Kuo, F.E., & Sullivan, W.C. (2001). “Environment and crime in the inner city: Does vegetation reduce crime?” Environment and Behavior, 33(3), 343-367.

Trees Linked with [Less] Domestic Violence in the Inner City: Aggression and Violence are Reduced with Nature Nearby.
Kuo, F.E. & Sullivan W.C. (2001). Aggression and violence in the inner city: Impacts of environment via mental fatigue. Environment & Behavior, 33(4), 543-571.

Where Trees are Planted, Communities Grow: Green spaces entice neighbors outdoors on a regular basis, where they build friendship and ties to one another.
Kuo, F.E., Sullivan, W.C., Coley, R.L., & Brunson, L. (1998). Fertile ground for community: Inner-city neighborhood common spaces. American Journal of Community Psychology, 26(6), 823-851.

*Ulrich, Roger S. (1984). “View Through a Window May Influence Recovery from Surgery.” Science, Vol. 224, No. 4647, April 27, pp. 420-421.