7 things to know about gardening with clay soil

There are some tricks to gardening with clay soil, which can be dense and compacted. With the right techniques, clay soil can benefit your garden by providing lots of nutrients to your plants and retaining moisture.

Clay soil is comprised of extremely tiny soil particles that stick together when wet and leave only a little space for air between the particles when the soil is dry.

• The density of clay soil makes it heavy to lift and slow to dry out.
• On the plus side, clay soil that is generously enriched with organic matter retains nutrients and moisture for a long time. As a result, plants that are well rooted are able to tolerate periods of drought well.

Any low spots where rainwater puddles for a long time are signs of particularly poor drainage.

• If you want to garden in such a spot, consider using raised beds or stick with nature's plan and turn the area into a bog garden.

Many gardeners find that gypsum — a rock powder containing calcium sulfate — helps to loosen tight clay, improving soil structure and aiding air and water penetration.

• Spread and work in 4.5 kilograms of gypsum per nine square metres for a new garden bed.
• Repeat every four or five years.

• Use a digging fork to make punctures in tight clay before you begin cultivating it with a spade.
• Push the fork into the soil and wiggle the tines slightly as you pull it out.

It's a technique that improves drainage by breaking up compacted subsoil.

1. Dig a trench about one spade depth deep and .6 metre wide; set the soil aside.
2. Work a layer of compost or well-rotted manure into the base of the trench using a garden fork to its depth, then dig another trench alongside the first, putting the soil from it into the first trench.
3. Continue digging side-by-side trenches, using the set-aside soil to fill the last one.

Clay soil tends to form a hard crust over germinating seeds, which can prevent small seedlings from pushing through to the surface.

• Instead of covering seeds with soil, plant them in shallow furrows topped with compost or potting soil.

Large cracks often develop when clay soil dries in the summer, which can cause injury to plant roots.

• Prevent cracks by blanketing the soil with an organic mulch of shredded leaves, compost or straw.
• As an extra edge against weeds, spread newspapers over the soil before piling on the mulch.

If you walk on or till clay soil while it's wet, you'll pack it even firmer.

• Install permanent paths between garden beds to provide areas from which you can work.
• If you must venture into beds when the soil is moist, stand on a board to help distribute your weight.