Even a postage stamp-sized yard is no reason to miss out on the beauty and enjoyment of trees on your property. Plant trees that are well-matched to your site and environmental conditions, and your urban garden will become a jewel box.
Size. Trees that reach mature height of 20 feet or less are the best bet for most urban yards. These small varieties have smaller root balls/systems, are less likely to interfere with nearby power lines, and will not crowd or shade out other plantings on your small lot. And there are a wide selection of these little beauties to choose from – fruit trees, flowering ornamentals, deciduous, and evergreens.
The diameter of the canopy also matters. The tree should be cited no closer to the house than half its canopy spread at maturity, which keeps the branches — and roots — a safe distance from your home. In the same vein, plant trees five feet from sidewalks and pathways, since spreading roots could cause these hard surfaces to heave and crack.
Resilience. Consider trees that are more tolerant of typical urban stressors: the spray and runoff from street and sidewalk de-icing salts, air pollutants from car and industry exhaust, compacted soils, and the “urban heat island effect” caused by all the surrounding hard surfaces. In addition, most urban soils have a higher pH than rural areas due to the materials in the streetscape that contain limestone. For those reasons, a good first step is to have your arborist perform a soil test to reveal important aspects of your site’s characteristics, including the pH of the soil, and the degree of soil compaction. Then s/he can recommend treatments, and help you choose tree varieties, with those characteristics in mind.
As always, consult your local arborist for the tree varieties that are best suited to your specific space and height constraints and grow zone.
Weeping Norway Spruce (Picea abies ‘Pendula’)
‘Pendula’ is an interesting and eye-catching specimen plant, whose branches cascade to the ground and develop a sprawling, prostrate habit.
Smoketree (Cotinus coggygria)
Grows 10′ – 15′ tall and wide, producing fine, light purple, feathery flowers in June. With blue-green to purplish foliage, this shrubby tree can be pruned to tree form.
The Cumulus or Autumn Brilliance varieties grow 15′ – 25′ tall and 15′ – 20′ wide. This large shrub can be pruned to tree form. Fragrant white flowers appear early to late spring. Edible berries emerge in late spring and last into late summer, attracting birds.
Apple trees usually grow up to 20 feet tall, while dwarf varieties grow 6′ – 8′ tall. Many varieties are available, all producing beautiful early spring blossoms. Some varieties are self-pollinating, though several others will require a “mate” nearby to produce fruit.
Though some flowering cherry trees can grow quite tall, there are smaller varieties, e.g., “Snow Fountain” grows up to 12′ tall, while “Sargent” cherry grows 20′ – 30′ tall. Weeping varieties are also available.
Star Magnolia (Magnolia stellate)
A smaller variety of magnolia that produces beautiful, white, star-shaped flowers in early spring. The flowers are fragrant and long lasting. Grows up to 20′ tall with similar spread.
Fringe tree (Chionanthus)
Grows from 12′ – 20′ tall with a broad, rounded form, and produces white, fragrant, lacy flowers in spring. Fruit on female trees attracts birds.
American Hornbeam (Carpinus caroliniana),
Also called ironwood. Grows 15′ – 20′ tall and has beautiful fall foliage that turns from yellow to red. Deep green leaves.