How to Garden on a Heavy Clay Soil

Heavy clay soils have a bad reputation, typically they can become water logged in winter rotting away at a plants root system. By stark contrast the height of summer can see the soil completely dry out and large cracks appearing in beds and borders. Despite this, clay also has some great benefits: it is nutrient rich and plants suited to the medium really with thrive.

Improving a Heavy Clay Soils

One way which a gardener may choose to deal with heavy clay soil is to try to improve the soil in itself. Key elements of soil improvement include improving the drainage of the soil which will help with both water logging in winter and cracking in the summer. In addition improving the soil may also include generally improving the levels of nutrient available. Clay soils also often have an association with high levels of alkalinity; the addition of large amounts of certain organic maters may also aid lowering the ph level of the soil is such a result is desired.

In order to improve the drainage of a heavy clay soil it is recommended that a mixture of sharp sand and organic mater is dug into the beds and boarders. When improving a soil it is important to improve the whole bed rather than simply the immediate area around which a plant is to be placed. If only the area around an immediate planning is improved then roots of weaker specimens will be bound to a smaller area thus stunting the growth of a plant.

Selecting Plants for a Heavy Clay Soil

Key to successful gardening on a heavy clay soil is the selection of the right plants in the first place. In addition to considering plants that will tolerate clay, one should also consider that in many cases plants will need to cope with alkaline conditions.

In general a gardener will have a greater level of success with plants which have strong root systems such as trees and shrubs than those of the herbaceous variety. This said there are plants available in all shapes and forms which will either thrive or tolerate heavy clay conditions.

Shrubs – Shrubs may provide the single biggest family of clay loving plants suitable for planning in the garden. Roses are a traditional favourite for planting a clay soil, the nutrient retaining nature of the soil benefits the plant and aids flowering. Roses can be thirsty plants however and as such the soil should not be allowed to dry out in the height of summer. Dogwood is also a good shrub for a heavy clay soil, the shrubs bark will also bring bright fiery colours to the garden during the depths of winter. Other good shrubs for clay soils include Hydrangeas, Holly and Junipers.

Herbaceous – Despite the delicacy of the root systems of some herbaceous plants there are still a number of suitable candidates. Campanulas make an attractive ground covering plant, with masses of usually blue flowers. For a more upright display a gardener may choose a variety of Asters or other varieties of the daisy family. Prairie plants such as Rudbeckia and Echinacea also do particularly well and bring a warm feeling to the garden late into the summer and on into autumn.