Small Trees for Home Landscapes
Marianne C. Ophardt
Washington State University Extension
Area Horticulture Specialist
Plant small trees. Of course, most trees are relatively small when planted in the home landscape, but only “small” trees stay a reasonable height for the normal home landscape. According to Dr. Ray Maleike, WSU Extension Horticulturist, smaller trees generally require less care than larger trees. He says, “Small trees can be chosen so that they remain in bounds, have multi-seasonal interest, and are hardy, resistant to pests, and drought tolerant.” He points out that when small trees do need care, such as pruning, irrigation, fertilization and spraying, the task is much easier because the tree isn’t so tall.
Larger trees also often create problems with their root systems. The roots of larger trees tend to be more invasive, causing problems with sidewalks, driveways, and lawns. It’s prudent to note that the roots of a tree frequently extend as far from the trunk as the tree is tall. This root growth can be quite rapid, with the roots growing to three times the branch spread within two to three years after planting. Just imagine how far out the roots of large shade trees, with crowns that grow to heights of 50 to 80 feet, will reach! The smaller the tree, the smaller the root problem.
Smaller trees seldom require extensive pruning to keep them in bounds. Usually only minimal pruning ... to enhance the shape or remove limbs with undesired placement... is needed. Large shade trees tend to outgrow their space in the landscape and can require costly, extensive pruning as they grow older. Even large trees don’t “need” pruning except to remove dead or damaged wood. However, pruning is frequently necessary to keep large trees within a reasonable size for the home landscape and to avoid problems with overhead utilities.
While there are a number of lovely shade trees available for use in the home landscape, few offer the seasonal interest that smaller specimen trees display... such as spring flowers, fruit and fall color. Attractive bark and winter silhouettes are also desirable characteristics.
When selecting any type of tree you should consider:
- Mature size of the tree: Is the tree suited to the site and home design? A large shade tree must be sited where it will provide the shade needed and where its roots won’t cause problems. The proximity to overhead and underground utilities, septic systems, swimming pools, building foundations, and paved areas should be assessed. In many situations you want to select trees that don’t grow too tall because they could block a desirable view from your home.
- Pest resistance: Small or large, it’s always a good idea to select a tree that’s not prone to insects or diseases. This is important in reducing pesticide use and lowering the maintenance time required to keep a tree healthy. Avoid pest-prone trees that will require lots of attention, such as white birch which is frequently attached by bronze birch borer or some varieties of flowering crab apples which are bothered by powdery mildew.
- Adaptable to the climate and environment: Many gardeners persist in planting trees not well suited to a particular area. Trees should be winter hardy to UDSA Zone 6 and able to withstand the summer heat stress experienced in this region. Trees that are marginally hardy or prefer milder summers, such as vine maple or quaking aspen, are harder to grow successfully here. It’s upsetting to grow a tree for several years and then have it damaged or killed during a cold winter or stressed by hot summer weather.
- Adaptable to site: Pick a tree suited to the soil conditions and site that has been selected. Trees that do better with in a protected location with some afternoon shade, such as flowering dogwood or Japanese maple, should not be placed on the south side of a building surrounded by concrete and rocks.
- Trees with seasonal interest: Many trees, especially the smaller trees, offer seasonal interest to the landscape... flowers in the spring or summer, fragrance, fall color, fruit, interesting bark, or distinctive winter form. Don’t just settle for nice green leaves in the summer, select a tree that will provide you with appeal all through the growing season.
Small Trees to Consider for Our Region
Flowering Dogwood (mature height 15' to 25' depending on the cultivar) - this is a favorite small tree of many gardeners but it’s not really well adapted to our summer climate and often suffers summer leaf scorch from extended spells of 90+ degree weather. While it’s difficult to establish in this area, once it’s growing well it seems to thrive here. It has wonderful white flowers in the spring and a rich red fall color with bright red berries. It should be planted in a protected location.
Japanese Maple (mature height 6' to 20', depending on the cultivar) - another favorite gem of gardeners everywhere, but it’s also generally not well adapted to our summer climate or soils and often suffers from leaf scorch when not placed in a protected site away from hot summer sun and wind. In the right place this can be the most beautiful tree anywhere. It may not have remarkable spring flowers, but its delicate dissected leaves and fall colors are a delight. There are upright and graceful weeping forms available. Some forms also have colorful winged seeds that provide color interest in the summer. Be sure to look for heat tolerant cultivars.
Flowering Cherry (mature height 12' to 50', depending on cultivar) - perhaps one of the most beautiful small flowering trees available. You’ll find a variety of flower forms from white to pink; large or small; single or double. The tree form varies with upright, spreading, and weeping forms available. Many cultivars have a bronze to deep red fall color. Borers can be a problem, especially if the tree is stressed, and is also subject to several fungus diseases that attack trunks, leaves and twigs. Consider a flowering cherry a short-lived (20 years) tree.
Paperbark Maple (mature height 25') - this is an interesting little maple with dark green, tri-foliate leaves that turn a brilliant red in the fall. The exquisite reddish bark peels off in thin sheets. The form is upright oval to round. This is a wonderful small maple, especially in the fall and winter landscape.
Redbud (mature height 20' - 25') - here’s a tree that everyone falls in love with when they see it in springtime bloom, especially those cultivars with deep, purple-rose flowers. Flowers come out before the leaves in early spring and adorn the bare branches. The tree usually branches close to the ground and develops a spreading, somewhat flat-topped crown. Look for heat resistant varieties like `Oklahoma’ with glossy leaves and red tipped new growth.
Amur Maple (mature height 5' to 25' depending on the cultivar) is another small maple that should be considered for its magnificent orange-red fall color. This tree is a low branched, multi-stemmed tree with a variable shape. It’s very winter hardy and can be utilized in above-ground tree planters. For dependable fall color select a cultivated variety, such as `Flame’ or ‘Red Rhapsody.’
Dwarfs or Giants
In the nursery trade there are some cultivars of larger trees that meet the size criteria of a “small” tree. While they may not have quite the pizzazz of these other smaller flowering trees, they can still be utilized in the landscape where a smaller tree is needed.
Leprechaun™ Ash is a dwarf form with a mature height of 18' of the green ash.
Golden Desert Ash™ (mature height 20') is a cultivated variety of the common or European ash with yellow-green leaves and bright golden twigs.
Red Cascade™ or Dwarfcrown is a compact (mature height 16', mature spread 8') cultivated variety of mountain ash with an oval shape. It has white spring flowers, yellow-orange fall foliage, and orange-red berries for multi-seasonal interest. `Longwood Sunset’ is another smaller mountain ash with orange berries
Globe Norway Maple (mature height 15') is a “lollipop” tree with a dense rounded head that is much shorter than other Norway maples. This is a very formal looking tree.
Harder to Find and Not Well Tested for This Area . . . But Worth a Try
Serviceberry (mature height 15' to 20') might be called a shrubby, multi-stemmed tree or a large shrub with early spring white flowers and bright red fall color. Some cultivars also have purplish blue berries. Plant these in a more protected location where they’ll get afternoon shade.
Japanese Tree Lilac (mature height 20') is another shrubby tree or large shrub that develops a graceful form with age. It’s covered with showy white flowers in the spring, but their fragrance isn’t the lovely scent of the common lilac. It may not stand up well under our summer heat, so plant where it will receive afternoon shade.
Kousa Dogwood or Chinese Dogwood (mature height 20') is not as well known as its cousin, but Kousa cultivars deserve just as much attention for their striking flowers. Here’s another one that should be kept out of the afternoon heat and you’ll need to condition the soil with organic matter, sulfur, and acidifying fertilizers since it prefers acid soil conditions.
Persian Parrotia (20' to 40' in the south) this is a beautiful tree with unusual upright or spreading oval form and texture. Its fall color is a breathtaking mix of yellow, orange and red. The bark is an interesting exfoliating gray, green, white and brown.