March 13, 2010
Our small courtyard garden is shaded by seven Japanese maple trees, which in early spring leaf out in delicate, feathery, pale green or rose leaves - a sight almost as lovely as their colorful autumn performance, when their leaves turn bronze, red and gold. In winter I welcome the sculptural quality of their bare branches against the sky, while the understory of shrubs and ground covers welcomes the sunshine they miss in summer when the trees are in leaf.
These are small trees, 20 to 30 feet tall, whose width I judiciously trim back (in February) if they become too expansive. These maples not only fit nicely into our landscape, but also will not get so large that they grow out of scale with our garden space.
I've learned two important lessons in gardening with trees in small spaces:
- First: Plant them to the scale of your garden, with large trees in large gardens and small to medium trees in the smaller garden spaces one finds in most suburban neighborhoods. I love California's mighty native trees, like the magnificent coast live oak, Bishop pine, Douglas fir and California redwoods, all evergreen and familiar. Perfect for parks and large garden settings, where their height and visual strength doesn't dominate. But living with one of these giants in a small urban landscape creates challenges for even an experienced gardener.
In addition to creating quantities of year-long shade, they are messy - dropping leaves, needles or acorns. These require removal, especially difficult to do around ground covers, perennials and smaller shrubs. The trees soon grow out of bounds, towering overhead, losing their relationship to an intimate, human-scale environment. Large trees periodically require expensive professional pruning. They certainly have their place, but you should plan for your future and theirs before you plant them.
- Second: Plant trees that perform, in the sense of doing something, like produce colorful leaves in the fall, fruit in summer, flowers in spring, or some combination. We are fortunate to live in a climate where our garden choices are almost unlimited, where many beautiful and productive plants thrive.
In our courtyard, I also have a flowering plum, my harbinger of spring. It's one of the smaller plum cultivars, happy living at the edge of our sunny patio. Pruned in late February after blessing us with a quantity of double pink flowers on its slender branches, it needs no further maintenance until its leaves fall in autumn.
Another favorite, in my neighbor's garden, is the fuyu, Japanese persimmon, a small tree (to 30 feet) with attractive, large, medium green leaves that turn orange and red in the fall. Its edible fruit is nonastringent and a brilliant orange when it ripens in November.
Occasionally what a garden needs are nondescript evergreen trees or a hedge to provide a background against which more-flamboyant trees or shrubs can shine. In this case, finding small to medium evergreen trees is not so easy.
From the lessons of my own garden and what I've observed in the gardens of my friends and neighbors, I have developed a list of evergreen and deciduous small-scale trees that are easy to grow in Marin County, do not require high maintenance, and when established need little or no water. Any combination of these would suit a small urban garden.
Here's an abbreviated list:
Small evergreen trees
- Citrus: Try a Meyer (Improved) lemon or Rangpur lime; both require little maintenance, flower sweetl and are followed by a bounty of fruit. Citrus is easily kept in shape by mild pruning.
- Podocarpus (P. gracillior and P. macrophyllus): A handsome, shrub or small tree. Can be pruned to fit a narrow passage, become a hedge, or left informal. No fruit or flowers, but a foil for plants that provide both.
- Ceanothus 'Ray Hartman': One of the prettiest Ceanothus cultivars, Hartman can be pruned as a single or multi-trunked tree. Its spring bloom is a gorgeous, abundant, sky blue. Fast growing to 35 feet.
- The smaller pines: Japanese white pine (Pinus parviflora) and Japanese black pine (Pinus thunbergii) are candidates for a woodland background, or as a focal point in a Japanese-style setting. Austrian black pine (Pinus nigra) works well in a corner of my courtyard, with huckleberry, camellia, columbine and ferns beneath.
- Arbutus unedo, strawberry tree: Slow to get going, but worth the wait. In ten years a handsome small tree with delicate white bell-like flowers and red fruits (like strawberries) in winter. Matures up to 35 feet. The fruits drop, so don't plant it next to a patio or path.
Small deciduous trees
- Japanese maple: Avoid the larger maples and plant out of high winds, with afternoon shade. Prune to shape while still young (under 5 feet). Do not let dry out until fully established and mulched. For cooler, shady places, and a less-formal appearance, look to vine maple (Acer circinatum).
- Crape myrtle (Lagerstroemia indica): For warm and sunny places, this small tree produces a summer bonanza of flowers from deep red through pinks to white. Dwarf forms available.
- Crabapple (Malus floribunda): The crabapples are worth exploring for small gardens. This Japanese flowering crabapple has a delicate branch structure and blooms profusely in spring with red/pink buds opening to white.
- Flowering plum (Prunus X blireiana): One of the smaller-scale purple leaf plums, its bloom is often the first sign of spring in late winter. Prune after flowering to retain shape and size.
- Western redbud (Cercis occidentalis): A multitrunked tree or large shrub (6 to 20 feet) produces magenta- to rose-colored delicate blossoms in late winter along its many branches and slender trunks. Drought resistant, it requires sun and a warm place. This California native can be spectacular when mature.