As a gardener facing a yard full of clay, you don't have the luxury of planting without soil preparation. Increase your odds of long-term success with the necessary alterations to ensure proper drainage and soil nutrients. Limit your landscape plants to the many, appealing clay-tolerant choices. They include several small trees with showy blooms and attractive foliage.
Eastern redbud's (Cercis canadensis) adaptability has earned it recognition as the state tree of Oklahoma. The quickly growing tree tolerates well-drained clay, sand or loam soil. Mature specimens typically range from 20 to 30 feet high and up to 25 feet wide. Eastern redbud has a uniform, vase-shaped habit with multiple trunks and flat crowns. Its rose-purple, early spring flowers emerge before its foliage from bud clusters along its branches. The dense, pealike blooms nearly cover the tree. Small brown seedpods follow the flowers. The up to 8-inch, heart-shaped green leaves become yellow in fall. This tree performs well in full sun to shade and winter temperatures as low as minus-25 degrees Fahrenheit.
Carnelian Cherry Dogwood "Spring Glow"
"Spring Glow," a carnelian cherry dogwood (Cornus mas) cultivar, tolerates a range of moist soils, including well-drained clay. Standing 15 to 25 feet high, with a 12- to 18-foot spread, Spring Glow handles winter temperatures in the minus-20-degree-Fahrenheit range. Forsythia-yellow, late-winter to early-spring blooms precede the tree's deep green, oval leaves. The drooping branches' foliage becomes red in autumn. This dogwood also produces edible, red berries. Attracting birds to the garden, they also work well in preserves. Spring Glow grows in full sun to shade. Root-cooling mulch improves its drought tolerance.
Japanese Tree Lilac "Ivory Silk"
Japanese tree lilac (Syringa reticulata) "Ivory Silk" is a 20- to 25-foot tree. Cascading clusters of creamy white florets nearly obscure its long, narrow deep green leaves in late spring or early summer. While they lack the sweet fragrance of French lilacs, they make the plant an eye-catching garden feature. Green clusters of seedpods and red-barked, new growth add further ornamental interest. Sun-loving Japanese tree lilac survives winter temperatures to Zone 4's minus-30 degrees Fahrenheit. It tolerates urban pollution as well as infertile, alkaline soils. Trees in clay, however, benefit from good drainage and an annual fall application of aluminium sulphate. The chemical lowers soil pH and improves the tree's nutrient absorption.