Gardening on Clay and Sandy Soil

Tips for Gardening on Clay

Individual clay particles are so small they are visible only under a microscope and clay soil is made up of more than 25 per cent of them. Mixed with water, they can be sticky and cement-like. Where there are less than 8 per cent clay particles, yet the soil is still heavy, there could be silt mixed with the clay. Silt compacts easily but is less sticky. Tiny particles mean tiny pores and a clay or silt soil is less well aerated and dries much more slowly than sandy soil. Although sticky clay soils can drive you mad when they bake hard in summer and are too wet to work during winter, the very nature of those tiny particles means they can hold onto water and nutrients and are great for plant growth. A wide range of plants, including roses, relish improved, fertile clay soils and if you switch, as I have, from impoverished sand to silty clay, you will certainly see a difference in growth rates.

Tips for gardening on clay
- If you need to access heavy clay soil or are standing on a lawn edge, use boards to spread the weight.

- Improve drainage for crops like garlic by planting into ridges made above soil level. This is especially useful for winter crops and early plantings because the roots are raised out of the coldest, soggiest part of the soil.

- To dry a cold, wet, heavy soil early in the year prior to planting and sowing, cover with plastic sheeting. Alkathene piping fixed over beds in hoops will raise the plastic off the soil to keep rain off but will allow air in to dry and warm the soil.

- Drying soil by covering is easier when the beds are only 4 feet or so wide and slightly raised above the surrounding level.

Tips for Gardening on Sandy Soil

The large particles making up sandy soils refuse to bond together into a good crumb structure, and this means they lose water quickly and don’t hold onto nutrients well. But gardening on a light, sandy soil is not all bad. These soils warm up quickly in spring and you can tread, fork, and dig them on virtually any day of the year. Improvements include adding lots of organic matter, but you’ll find this disappears quickly. There are plenty of plants more than happy to grow on well-drained soils, including many of Mediterranean origin. Herbs such as lavender, thyme, and rosemary will be much happier on sand than a sticky clay. Plants of dubious hardiness will come through hard winters much better with drier roots and survive on sands when they would have rotted away on damp clays.

Tips for gardening on sandy soil
- A good way of conserving water in sandy areas is to mulch beds with a layer of shingly stones. Start by digging and enriching your flower bed with plenty of humus. Choose a good range of drought-tolerant plants and plant them slightly above the soil. Water thoroughly and mulch with a 3-4-inch layer of shingly stones (not too fine). The stones will help to keep out the weeds and protect the soil from evaporation.