Add lime your soil if it’s a little too acidic to help keep your crops healthy and avoid disease. You can find out how acidic your soil is using an inexpensive soil testing kit – available from our garden centre here in Henley on Thames. Your soil can change from year to year, so test regularly.
Acidic soil is a particular problem as brassicas hate it and sulk, or worse, develop clubroot. So if your soil’s pH is less than 7, tip the balance back in favour of your cabbages by liming. This is best done this month, as it takes up to six months to have an effect.
You can find treatments here at the garden centre, including dolomitic limestone, calcified seaweed and garden lime which will all raise the pH of your soil. Follow the instructions on the packet: you shouldn't increase your soil pH by more than 0.5 each year, so don't add too much.
Choose a calm, dry day and scatter the lime evenly across the soil, then fork it in. Don't add any other fertilisers – including manure or compost - for a month or two before or after, as lime will react adversely with them. Once limed, your soil should stay sweet for up to three years.