How to Improve Soil Quality for Healthy Plant Growth

By Sven Wombwell from Allotment Gardening For Dummies

Good quality soil is essential to the successful allotment plot. Without fertile, nutrient-packed soil, your careful efforts at sewing, weeding and tending your garden or allotment will all be in vain. Soil provides the food, water and some air that your plants need for healthy growth and development, so it’s worth spending time trying to improve its quality.

Soil types as growing mediums

Soil can be judged as to whether it is sandy, silty, clay, loam or chalky. Each of these has its own characteristics, which can be improved in different ways. Sandy soil doesn’t retain nutrients well, so needs to kept well supplied with organic matter.

Silty and loam soils are regarded as very good for growing, and need less work. Clay soil is more problematic: it can lack aeration and good structure needed for growing. The best solution is to add lots of well rotted organic matter in the autumn.

Chalky soil is the worst for cultivation because it is naturally highly alkaline which causes mineral deficiencies. One way to rectify this is to add bulky organic matter to improve the soil’s nutrient content and water retention.

pH levels of your soil

Most plants prefer a neutral soil, but some prefer slightly acid or alkaline conditions. Before planting, find out your soil’s pH level. Testing kits are widely available at garden centres. If necessary, you can adjust the pH levels slightly according to the type of fruits and vegetables you want to grow.

Add ground lime to make your soil more alkaline. To make your soil more acidic, you need to add aluminium sulphate or sulphur. It’s worth bearing in mind that you can’t permanently alter soil pH levels – such measures will have only a temporary effect. Your best bet is to work with the soil you have, as far as possible.

Feeding your soil for successful growing

Think of your soil as a breathing organism that needs feeding and watering, just like a living creature. Three main nutrients (nitrogen, phosphorous, and potassium) are essential to healthy plant growth. Organic fertilisers like horse manure are rich in these. However, you’ll need to ensure that trace nutrients (iron, boron, copper, manganese, molybdenum , zinc) are also added.

Living organisms are crucial to healthy soil, and you should encourage their development. Mycorrhize is a type of fungus that helps plants to absorb more water and nutrients. Treatments can be purchased from garden centres and are incorporated into a planting hole or plot.

Worms really are a gardener’s best friends. They feed on organic matter and then disperse it through the soil. They’re great at speeding up the composting process. You should also encourage creepy crawlies to spend time in your plot: they can keep pests at bay and so keep balance within the great circle of life.

Be careful if you resort to chemical sprays to control pests, because this will kill the good critters too. It’s usually better to adopt an organic method of gardening: pesticides and fertilisers interfere with the careful balance of nature in the soil.