How to Improve Clay Soil

Characteristics of Clay Soil

The three main types of soil are sand, loam, and clay. They are classified in terms of the size of their particles, with sand having the largest soil particles and clay having the smallest. The issue with clay soil is that all of those tiny particles make for a dense, sticky soil. Clay soils tend to hold onto water, which can be good or bad depending on the situation. The problem comes when clay soil dries. The surface of clay soil becomes cracked and hard, and water and nutrients can't get down into the soil. On the upside, clay soil is the most nutrient-rich of all soil types, so if you can solve the texture issue, you'll have great soil for growing all types of plants.

Steps to Improve Clay Soil

Add Organic Matter-Lots and Lots of Organic Matter

The absolute best way to improve the texture of clay soil is to add plenty of organic matter. Consider adding any or all of the following:

• Compost
• Rotted Manure
• Leaf Mold
• Straw
• Grass Clippings
• Chopped Leaves

Add a layer from two to six inches deep of whatever organic matter you choose, and use a shovel to dig it into the top six to ten inches of soil. For best results, this should be done once every year, as the organic matter will break down fairly quickly. In an established garden, try to work it in between plants. If you can't do that, simply incorporate the organic matter into the planting holes when you plant new bulbs or plants.

Mulch

Clay soils should always be mulched. A three-inch layer of shredded bark, grass clippings, hay, or chopped leaves will prevent the soil from crusting over. As an additional bonus, the mulch will improve the soil as it breaks down. You may need to add new mulch once or twice per year.

Plant Cover Crops

Cover crops, also commonly called 'green manure', can be planted in bare spots in your garden. They are of particular benefit in vegetable gardens or annual beds where nothing will be growing for a good part of the year. Cover crops add organic matter (and sometimes nutrients, depending on the crop) to the soil, serve as a kind of 'living mulch' to keep weeds from germinating, keep the soil moist, and prevent soil erosion. Some common cover crops include:

• Winter Rye
• Winter Wheat
• Crimson Clover
• Oats
• Hairy Vetch
• Alfalfa

Simply plant the cover crop at the end of the growing season, let it grow throughout the winter, and then, in spring, use a tiller or a shovel to dig the entire crop into the soil.

What You Can Expect

After the first season of using these methods, your clay soil will be richer in color and less 'sticky.' By repeating these methods every year, within four years you can expect to have crumbly, nutrient-rich soil that your plants can thrive in.