March Calendar
For gardeners across the land the arrival of March marks the start of spring. Shoots of herbaceous perennials will be starting to grow vigorously as the weather warms and gradually the garden comes alive. The soil is still moist from the winter rain and is starting to warm up too, so it’s a good time to plant now as it allows new plants to get their roots established before summer arrives.
It’s the month for seedlings, seeds and sowing, but also the month that nature has similar ideas. As the weather improves and the days lengthen it’s a message to weed seeds in the garden soil to start growing and when that happens it’s a sign for the gardener that the conditions are right for sowing and growing seeds. It’s also a sign to get the hoe out and keep on top of weed seedlings.
March is a great time to plant containerised trees and shrubs. Don’t forget that bare rooted plants that have been lifted over the winter also need to be planted now so that they are in position before they start into growth in spring. Make sure you improve the soil in the planting hole with a quality planting compost. Mix it in with the existing garden soil to enable the roots to quickly establish into the ground in search of water. It is also essential to keep newly planted trees and shrubs well watered for up to two years, particularly in dry spells. It takes a while for the plants to reach down to moist soil to support them during hot weather or when there has been little or no rainfall.
Now that spring has arrived garden plants will start to grow vigorously. This is when they need rich levels of nutrients to support and sustain their growth. See feeding (link to feeding feature for more information).
Keep weed seedlings under control. Any bare soil will quickly be covered with a fresh crop of seedlings as soon as the weather starts to warm up and conditions for growth are present. Weeds that germinate in early spring can be quickly and easily removed by hoeing them off at ground level on a bright, dry day. Leave them on the soil surface to shrivel in the sunlight and they are unlikely to regrow. Perennial weeds need digging out complete with their roots as every piece of root left will regrow into a new plant. Every perennial weed removed now will save you hours of work later. Get them out before they start flowering or seeding.
Rumour has it that we are in for a barbecue summer! Haven’t we heard that before? We’ve been a bit short on rainfall for the last few weeks, but a garden mulch applied now, after a heavy rainfall will help preserve soil moisture. Mulch around permanent trees and shrubs to conserve the moisture that is held in the soil, this will keep weeds down too and insulate the roots from extreme cold. Use well-rotted garden compost or buy a quality garden mulch from the garden centre.
Keep a watch out for slugs and snails that will start to become more active now the weather is improving. A torchlight slug search will reveal a massive amount of these slimy fiends; you can collect them up and deal with them in your preferred way.
It’s time to sow seeds en masse. The weed seedlings in the garden are sprouting so conditions are good. If you don’t have too much room to pot up and grow on lots of plants then delay sowing until next month, or later, you have plenty of time. Many half hardy annuals and vegetable seeds can be sown in March.
Sow annual flower seeds such as Ageratum, bedding Salvias, Tagetes, Diascia, annual Stocks, Nemesia, Nicotiana, annual Phlox and bedding Rudbeckia in pots in gentle heat in the greenhouse.
Sow Nasturtiums, Alyssum, Clarkia, sunflowers and Lupins in pots of quality seed compost in a frost-free greenhouse or on the windowsill.
Sow lettuce, salad, Swiss chard, cabbage in pots in the greenhouse.
Outside sow broad beans, beetroot, radish and parsnips into a prepared seedbed. Plant out greenhouse sown early peas and place pea netting or pea sticks along the row for them to grow up.
Keep the greenhouse well ventilated especially on sunny days. Open windows and doors in the morning of a fine day but close again mid afternoon before the temperature starts to drop.
Keep a close check on plants, seeds and seedlings in the greenhouse and keep the compost moist but not waterlogged.
If the soil is workable, sow parsnip seed. They can, depending on the season, take up to 7 weeks to germinate.
Sow outdoor tomatoes in a propagator in the greenhouse as soon as possible to get the optimum harvest before autumn sets in. Cover the seed over with Fine Vermiculite rather than the compost itself. Place the pots of seeds into a propagator for even germination. If you haven’t sown any then look out for plants at the garden centre or order them from a mail order supplier.
Plant out shallots directly in the soil, space them 6in apart and 12in between rows.
Finish pruning roses and feed with a dedicated rose fertiliser. If you plants suffer from Blackspot then treat them to a rose tonic containing sulphur, as it will deter Blackspot from affecting your plants as well as make soil nutrients more available.
Hard prune Cornus stems back to the ground to generate fresh new stems for the season. Be brutal, these plants respond to hard pruning, but keep the cuts clean and smooth.
Tidy up summer fruiting raspberry canes, these will fruit on last year’s canes, so simply remove the top six inches or so and ensure that your support wires are tidy and in good order. Autumn fruiting varieties fruit on new canes and should have been pruned to ground level after fruiting. If you haven’t done this already, cut them back now to generate new stems.
