Planting shrubs in clay soil can present numerous challenges for the gardener. Clay soil is heavy, does not offer good drainage, is low in nutrients and forms a hard crust after heavy rains. It often becomes so compact or water-logged that it can deprive a shrub's roots of oxygen and even slow or stunt growth. Despite the many challenges of gardening in clay soil, there are a few varieties of shrubs that can be grown in heavy clay soil.
Glossy buckhorn (Rhamnus frangula) is a deciduous shrub that produces leaves in the early spring and retains its leaves into the first weeks of winter. The shrub can quickly form a nice rounded thicket even in heavy, water-logged soil. It will attain a height of 20 feet with ease. Glossy buckhorn can become invasion in moist wetlands. Birds and mammals enjoy feeding on the bright red berries that the shrub produces. Glossy buckhorn is believed to have been introduced into the United States in the 1800's from North Africa, Europe and Asia. By the 1900's the plants became widespread across most of America.
Scarlet elder (Sambucus pubens) grows approximately 12 feet tall with a 12 foot spread. The shrub produces large plumes of white flowers followed by red berries and flourishes in moist, clay soil conditions. The shrub is often pruned to resemble a tiny tree.Scarlet elder can flourish in wet clay soil conditions, but it does not tolerate seasonal flooding well. The plants also do not do well with staggering summer heat. Scarlet elder can easily be planted in shady conditions. The berries of the tree are toxic to humans, but songbirds can consume them with no adverse effects. Large and small mammals also enjoy feasting on the berries.
Russian olive (Elaeagnus angustifolia) shrubs can easily grow to 15 feet in height. The shrub grows in a wide variety of soil types. It will flourish in soggy clay soil conditions. The shrubs are considered to be highly invasive if let spread into a forest setting. Leaves are a silver color with thorns on the stems. Yellow or white pleasantly fragrant flowers are produced in the spring, followed by tiny yellow fruit. The fruits are adored by many birds. The shrub can be easily shaped into a tree form.
Northern Bush Honeysuckle
The northern bush honeysuckle (Diervilla lonicera) is a small, rounded deciduous shrub that grows approximately 3 feet in height. Each fall the shrub sports outstanding autumn colors. Each spring, flowers appear yellow, then rapidly turn to orange and finally red. Flowering extends all the way into August. The small shrub can flourish in sun or shade. It enjoys sandy loam soil or soggy clay. It is highly versatile in any garden setting and easy to grow.