Garden work for March.
Our heavy clay soil is great for retaining moisture, but it is easily compacted, especially in wet weather. So try to use short boards of about i.5 metres (5’) length to stand on when digging the soil in preparation for all the growing that will come.
March is the time to start laying the basis for a good lawn through the season. First lightly rake the grass to get rid of all the debris. Do a first cut when it has dried out a bit, but remember to set the mower blades high. Cut the edges with a half-moon cutter, or use edging shears.
It is a good time in March to increase your stock of perennials like delphiniums, pulmonarias, dahlias and chrysanthemums. The way to do it is to look for shoots of about 5cm long, take them as cuttings using a sharp knife to remove the shoot at root level. Pot them up individually in small pots using a mixture of 7 parts compost and 3 parts vermiculite. Put them in a cold frame, or an unheated greenhouse and they should root in about 10 days. Once they are rooted, repot in larger pots of compost (perhaps John Innes No.2).
Half-hardy annuals like marigold, sweet alyssum, annual phlox, ten-week stocks, asters and zinnias should be sown in seed trays and kept under cover towards the end of the month. They will benefit from a bit of gentle heat (around 10ºC) to start them off.
Ornamental grasses that have been left to show their form over the winter should be cut back in March to encourage new growth. Hybrid tea roses should be pruned in March. Cut them back to 30 cm above ground. Remove all disease or damaged stems. Side shoots of floribunda rose should be pruned to about 15 cm.
Protect the new shoots from established plants (like hosta, delphinium and clematis) from slugs and snails with an appropriate treatment.
An old rhyme to think of when sowing your peas is as follows: “One for the mouse, One for the crow, One to rot, And one to grow.”
Start leeks under glass for pricking out and transplanting at the end of the month. Salad crops such as lettuce can be started for transplanting once they have established themselves. Put them into the soil that you have warmed up under cloches or fleece.
In order to give the best germination of any seeds that you want to start, make sure that the soil, or seed compost, you use is as warm as possible. So put out cloches over the area in the garden where you intend to start early crops. Do this at least a week or so before sowing in order to warm the ground. Equally, if you are using a seed compost, bring it in to a shed or greenhouse before making up the pots or seed trays so that it has been thoroughly warmed through. Most seeds need a soil temperature of at least 10ºC (50ºF), and do better if it is about 15ºC. This is a very general rule of thumb*, and there are many differences for different species, but it is true for a lot of the plants we grow.