Frequently asked Questions about improving and breaking up clay soil Answered in this article
Clay soil can be a good thing many plants grow well in it.
Clay soils are hard to dig, but retain moisture better than sandy soil. Drought is much less damaging on clay soils than other soil types.
Clay is rich in the nutrients plants need to grow, holding calcium, potassium, and magnesium.
Improving the soil to make it easier to dig is a better and cheapest option than replacing it.
I'll show you how lower down on this page.
What is clay soil?
Clay soil is composed of mostly clay particles. Ordinary clay soil contains about 30 percent fine clay particles. Soil that consists of over 50% clay particles is referred to as heavy clay.
Clay soils take longer to warm up in spring and clay soils are easily damaged when dug or walked on.
Carry out this simple test to find out if you have clay soil: if the soil sticks to your wellies, garden spade and fork like glue and forms big hard lumps of soil that are difficult to break up and the garden surface cracks up in dry weather, it's clay. Types of Soil
What is bad about clay soil in my garden.
Clay soil can be a nuisance, even if it's not waterlogged. Hard clay soil is hard to dig and although many trees and shrubs grow well in clay. The roots of some annuals, perennials, and vegetables, especially root crops like carrots and turnips can't grow through heavy clay.
Clay soil is slow draining, slow to warm up in spring and compacts easily into large hard lumps of soil making it difficult for plant roots to grow.
In dry weather the surface cracks up.
What's good about clay soils?
Clay soils retain moisture better than sandy soil, handy during long dry spells. It's also rich in the nutrients plants need to grow, holding calcium, potassium, and magnesium. See the note here to understand a little more about calcium, potassium, and magnesium in garden soil.
YES, it is possible, with some hard work, to make clay soil more workable and suitable for planting and growing most plants and at the same time keeping the good things about clay such as the nutrients essential for plant growth. Clay also has moisture retention properties which can be useful during long dry spells.
Improving your clay soil will take a lot of digging, but will improve the structure of your soil making it easier to work.
The garden bed will end up a couple of inches higher when you have finished digging in the organic matter, however as the clayey soil improves will gradually settle down over a season.
Once you have started the process to improve and break-up clay soil without using chemicals, you will see the change, your spade and knees will feel it and your plants will thrive in it. Well worth the hard work! So get your wellies on and get started.
Now all you have got to do is maintain the improvement!
Each year as the clay soil improves, digging will become easier and the variety of plants you can plant will become greater. Read my article listing plants that will tolerate clay. Some root crops like Turnips, Radishes, Potatoes and Beets actually help break up heavy clay soils. But, what the clay soils will need to keep the improvement going to stay loose and workable is organic matter. As the clay soil improves, just after harvest time add more organic matter to the top of the garden bed each year. This can be left on the surface for the worms to take down into the clay for you. Or you can dig it in.
Think of worms as little gardeners digging and aerating the clay soil for you (and they don't need paying) As they toil away for free, taking the organic matter you have spread across the surface of the ground down into the earth to eat and feed their baby worms. Then, bringing nutrients containing nitrogen, phosphorus, potassium, and calcium back to the surface in the form of castings that provide the necessary nutrients and minerals plants need too thrive.
All worms ask in return is to be left alone to get on with it. Ohhh and a continual supply of organic matter.
The best time of year to start working to improve clay soil is late spring or early summer (providing the soil is relatively dry) right after the winter frosts have finished and helped break up the clay and the clay has warmed up a bit.
If you dig or walk on wet clay it loses its structure and can become puddled and compacted.
Grit sand for breaking up and improving heavy clay soil.
It's extra work but worth spreading a one or two inch layer of grit sand across the clay soil before spreading the organic matter and digging the whole lot in at the same time. This will help break up even heavy clay soil. You will need to work at it over the years by repeating the process though. Baked clay is almost impossible to break up, rotavate or dig, it's easier to spread the organic matter and grit and wait until the worms have done some of the work for you.
This is the Sharp Sand I use its composed of grains of rock, with a high percentage of larger grain sizes making it ideal for improving clay soil.
Bulk bags weigh a minimum of 800kg, cost about £80 inc delivery.
Do not use ordinary builders sand it will clog up the soil.