How to test your soil

Neat and tidy: Next week I’ll be clearing borders and showing you how to keep on top of autumn’s pests and diseases

Testing soil for top results

Check the pH and nutrient levels of your soil

TESTING your soil may sound off-puttingly scientific, but it is a cheap and effective process that helps you determine the acidity/alkalinity of your soils and what nutrients are in it so you get the best results from your plants.

It can also stop you buying the wrong plants for your plot, saving you money, frustration and heartache in the process.

Winter is a good time for testing as soil will probably have been lying fallow during the dormant weeks of winter, so the test results should be ‘pure’.

Test kits are widely available online and from garden centres. There are extremely simple ones where you put a small scoop of soil into a tube of solution, shake it and wait for it to settle to reveal the acidity or otherwise of your beds.

Others are slightly more complex and enable you to assess nutrient levels around the garden and attend to areas where they are lacking.

I don’t need a test to tell me the acidity or otherwise of my garden. The soil is so alkaline that large lumps of chalk often work their way to the surface of the borders.

Plants that thrive include foxgloves, lavender, cistus and potentilla, agapanthus, echinacea and aquilegia.

Conversely, I know that if I want to grow acid-loving plants such as heathers, blueberries, rhododendrons

Testing soil around your garden shows where nutrients may be missing and camellias, I will need to do so in containers of ericaceous compost. What I am unsure of is the soil’s nutrient wealth, which is why I bought a kit that allows me to test for nitrogen (N), phosphorus (P) and potassium (K). These are the three most important elements needed by plants for healthy growth, foliage, fruiting and flowering, Yellowing leaves signify and are listed as ‘NPK’ on a nutrient deficiency bags of fertiliser. Once you have established which nutrients are present or absent, and in what quantities, you can start improving your soil.

Understanding crop rotation

CROP rotation is a system as old as cultivation, and benefits the soil and plants in three main ways: 1. It helps maintain and balance soil fertility, as different crops require different nutrients from the soil. Growing crops in different areas each year can reduce the risk of soil becoming deficient in one nutrient. 2. Swapping crops also helps stop a build-up of pests and diseases specific to different varieties of crops, such as scab in potatoes and clubroot in brassicas. 3. Crop rotation can even control weeds, as the spreading leaves of crops such as potatoes and squashes will shade out unwanted plants.

It isn’t difficult to set up a three or fouryear cycle of rotation of the main crop groups: brassicas (cabbage, cauliflower, sprouts, swedes, turnips); legumes (peas, beans); onions, shallots and garlic; the potato family (which includes tomatoes, peppers, aubergines); and root vegetables (carrots, parsnips, celery, celeriac, beetroot). Onions and roots can go in together and if you are sticking to a three-year system, plant legumes with them as well.

Stop digging

No-dig for healthy soil

Layering compost and manure onto beds without digging will help soil

n One of the easiest ways to improve your soil and grow well is the no-dig method, when manure and compost are piled onto a bed. n This is an especially useful technique for raised beds and narrow borders. n Worms, beneficial soil microbes and winter weather work their magic on the compost and manure, breaking it down into a rich and healthy mix. n Because nothing is dug, the structure of the soil isn’t damaged or compacted. n Weeds are controlled by gentle hoeing, hand weeding or mulching, and because fewer germinate as they are not raised to the surface, there is less cover for pests. n After each harvest the plants are lifted and more layers of organic matter are added, ready for the next crop.

Clubroot is a common brassica problem

Rotation keeps soil rich, and crops healthy and problem-free