Trees to Be Planted on a Roof Garden

Willows

• Fast-growing and hard-wearing, willows are successfully used in rooftop gardens. There are numerous variations of willows, so it is simple to find a style, height and weight appropriate for your space.

  Some types include the weeping willow, the willow hybrid—ideal for building privacy barriers—the black willow and the contorted willow. Often, willows will outgrow their containers. You can divide them for smaller containers or simply replace them with younger, smaller versions.

Dogwood Trees

• Dogwood trees are prized for rooftop gardens because of their small foliage, returning blooms and architectural branches. The root balls can remain relatively small if planted in a limited container, and pruning is acceptable, making it possible to control the size of this hardy tree. Dogwoods are also used to attract birds, bees, butterflies and other wildlife.

Japanese Maples

• Japanese maples are slow-growing trees that boast intensely red, small leaves in the spring and summer. They, in addition to other flowering trees—Oriental cherry and crab apple—require minimal repotting. Flowering trees and trees with vibrant foliage add color and fragrance to rooftop gardens during their blooming seasons.

Fruit Trees

• Fruit trees can be grown successfully on rooftop gardens and made to bear fruit during the blooming season. Apple trees and pear trees are excellent candidates because of their squatty stature. Fig trees will grow successfully, but unlike apple and pear trees, they can grow quite large. Consider replacing them with younger, smaller versions when this happens.

Evergreen Trees

• For rooftop gardens to remain lush and inviting during cooler months, it is important to intersperse some evergreen trees. Common, inexpensive evergreens such as the pine, yew and hemlock can be pruned annually to maintain a desirable size.

Palms

• For warmer climates, palms can create a great sense of height in a rooftop garden. Mediterranean fan palms, needle palms and palmetto palms are more suitable than their larger counterparts, the date palms and sable palms. You do not have to consider weight when selecting a dwarf palm, but understand that you will lose the height aspect.