The characteristics of clay soils are that they retain water, they are slow to warm as seasons change from winter to summer, and are usually compiled of a lot of plant nutrients. Because they retain water, they also drain slowly.
Clay soil should be dug when it is dry, in autumn or early winter. This is because once they become very wet from rain, they usually cannot be walked on, or worked with, until the middle of spring. This is because working with, and/or walking on clay soil when it is wet, leads to structural loss, and causes the soil to fill up with puddles, and become compact.
It is advisable to let winter frost break the clay soil down
If digging is needed to be done in winter time, dig the clay into narrow ridges. This process will permit the frost to break the clay down better, and permit better drainage.
Early planting or sowing should be avoided.
The issue of drainage can be resolved by making raised beds. The ground can also be covered with polythene sheets, for a minimum of six weeks, so that the clay soil can dry before, planting or sowing.
Trees, shrubs, roses, bulbs, and climbers, are better grown in clay soils, than annuals or bedding plants. This is because bedding plants, and annuals require frequent sowing, planting, or dividing. Planting trees, shrubs and climbers, are best planted in early autumn.
If woody plants are planted on raised mounds of 10 inches, this may help alleviate the problem of their roots being damaged by water build up.
Early vegetables are difficult to grow in clay soils, but main-crop vegetables usually do very well.
Tree fruits are better planted in clay soil. Raspberries, and strawberries are more difficult to plant in clay soil.
During rainy seasons, lawns made with clay soil, usually cannot be walked on, because they are too wet. There is a method used by golf courses: they lay turf on 3-6 inches of sharp sand, as a remedy to this problem.
TO IMPROVE CLAY SOIL
- Making raised beds is a method of improving drainage
- The less the soil is dug, the better
- If the soil is to acidic, lime can be added
- To improve clay, gypsum can be added. This is the active ingredient in clay improving products.
- Adding organic matter to the soil, like manure, or composted bark mulch can improve the workability or the clay soil
- Adding organic mulches around trees, and shrubs, reduces the amount that the soil cracks during the summer time. They will also keep in the moisture
ADDING SAND, GRAVEL, GRIT TO CLAY SOIL
Clay particles are very small, and there are a lot of them in a clay soil. Clay particles may be small, but this means that more of them can fit in one cubic yard of soil, than larger materials like silt, and sand. This means that clay soil covers greater surface area of soil, than sand, and silt. Practically this indicates that in order to dilute a part of clay soil, one will need a large amount of sand, or other material.
Royal Horticultural Society.(2017). Clay Soils. Retrieved from: