Clay Soil

Coping with a clay soil can be one of the most challenging aspects of gardening, particularly for beginners. But don't despair, I'd much rather have a clay soil than chalky or sandy, it's just a question of learning how to make the most of what you have got.

Characteristically slow to dry out

Able to "lift" water from the water table by capillarity

Established plants frequently survive drought periods well even if they are not watered through them

Usually very rich in nutrients

Plants that survive the first couple of years on clay tend to grow and survive very well with little intervention.

Always heavy to work

Slow to warm up in spring

Can be waterlogged

Plants planted into clays generally take longer to establish than on other soils

Growth can be fairly slow at first.

Having a clay soil can feel a bit like being at school, - you're going to do something new and the teacher brings out the equipment. But instead of paying attention, you were talking to your friend or daydreaming or at the toilet. Then when there's the mad scramble for the stuff, you get left with every body else's rejects. You know it's going to be difficult, but most of all it just doesn't seem fair!

If you've got clay soil, then you're probably acutely aware of the fact, but if you're not sure, then take a little moist or wet soil in your fingers and rub it gently, If it "polishes" i.e. makes a shiny smooth coating on your fingers and is greyish brown in color it's probably clay.

Dealing with clay - There are three key elements to improving clay soil

The weather helps to break the soil up in the winter by a freeze / thaw effect on the clods that you dig up. Digging the soil over in the autumn and then leaving it for the weather to act upon is the most effective way of breaking it up. In the spring, the soil can be broken down much more easily into a fine tilth by raking.
Organic matter is the way that you can improve the soil in the longer term. Garden compost, farmyard or stable manure and in large quantities, the bulkier the better. Dig it in if you can, but if there's just too much, then apply it as a thick layer of mulch in the autumn and then leave it for the worms to take down into the soil for you - slower, but effective.
Time is the third key element. Really it means repeating the above two, for several years. It will take a few years, 3,4 or even up to 10 of digging and adding bulky organic matter to really improve the soil for the long term. So keep on going!

If you have clay soil, never walk on it when it wet, you will compact it even more squashing out any pockets of air that it may contain and leaving it to develop a hard and caked surface when it dries out.

Knowing when to dig becomes a bit of a fine art in fact. Too wet and it's horribly sticky, too dry and it's horribly hard. I find a mattock (like a pick-axe, but with a large flat horizontal blade on one end) very useful if I have to work on a hard dry clay soil.

Use a fork rather than a spade to dig the soil.

Take more smaller bites with the fork, rather than trying to move too much soil in one go.

Plants for clay soil | Extreme clay soil