This is the Year of the Sweet Pea, so if you didn’t sow the seed in the autumn, now is the time to do it. Early in the month, sow in a greenhouse, conservatory, cold frame, or cool, light windowsill. Later on, if the weather has been mild, you can sow directly into the ground as you would with edible peas. If giving the plants an early start by starting them off indoors, sow one or two seeds in small pots of seed compost. Alternatively, use toilet roll tubes or kitchen roll tubs cut into two or three. The roots will grow into the cardboard, and the whole thing – tube, compost and young sweet pea plant – can be planted out in April without disturbing the roots.
Prune winter and early spring flowering shrubs as soon as the flowers have faded. These will blossom on the new shoots made over the coming year; pruning helps to keep the bushes tidy and of a manageable size. Those that are helped from cutting back and thinning in early spring include winter jasmine and Viburnum x bodnantense. Other shrubs and climbers that benefit from hard pruning in March are those that flower from midsummer onwards on new growth produced in spring and early summer, such as deciduous ceanothus, buddleja and later flowering forms of clematis. Towards the end of the month, remove old heads from hydrangeas that were left over winter to protect the buds beneath from frost. Don’t cut back hard, though, as you will remove many of this summer’s flower buds.
If diseases such as mildew, black spot and rust were a problem with roses last year, give all plants a spray with a rose fungicide as soon as the new buds appear after pruning. Apply a rose fertiliser around the roots and hoe in gently, taking care not to damage the roots as this may cause them to produce suckers.
March is traditionally the time to start mowing the lawn regularly; however, if the weather is cold or frost is still a problem, it is wiser to leave well alone. The first cuts should be made with the blades raised so the grass is just tipped; later on, when it is growing strongly, they can be gradually lowered. In most parts of the country, you can give the turf a feed at the end of the month, but in colder areas this job is best left until April. This is a good time to start preparing the site for a new lawn, by digging over and roughly levelling. The final preparations – raking the soil to make a fine bed – can then be done just before turfing or seeding next month.
Late leek crops may still be in the ground when you need to start getting it ready for this year’s crops. Leeks will remain harvestable for several weeks if they are lifted and ‘heeled in’ in a spare piece of the vegetable garden (or a large, well-drained pot of compost if you grow in raised beds); allowing you to start planting in the spot they occupied. If possible, don’t grow another onion-related crop (onions, shallots, garlic or leeks) in the same spot for a year or two, to prevent the build-up of disease.