Gardening begins again in earnest in March. It’s the first time in the year when we can regularly get out and work on the soil. Daylight hours will be lengthening to encourage growth and the soil temperature will be rising very slightly.
However, climatic differences between the various parts of the UK are more pronounced at this time of year and in cold and northerly districts it may be necessary to delay the commencement of sowing until the end of the month or even the beginning of April.
While various dates are given for the start of spring, it will vary with locality. In coastal and more southerly regions it tends to be earlier, while further north and inland it is later (the difference can vary by as much as a month).
In addition the actual date will alter from year to year and it must always be the state of the weather not the date on the calendar which determines when activities begin. From a gardening point of view, spring is the time when the soil has warmed up sufficiently for seeds of hardy plants to be sown.
The best indicator of the arrival of spring is that the grass grows much faster and needs cutting more frequently, and when the lawns (other people’s!) are covered in daisies it is safe to sow and plant. Hardy annuals to sow outside in March include calendula, callistephus (aster), centaurea (cornflower), clarkia, eschscholtzia, gaillardia, godetia, gypsophilia, iberis, nigella, phlox, poppies (various) and tagetes.
Should you miss sowing them this month, it is possible to sow them up to the middle of April but, providing conditions are right, the earlier the better.
Evergreen shrubs can also be planted this month, including berberis, ceanothus, cotoneaster,
hedera, lavender, pieris, pyracantha, rosemary, veronica, viburnum.
March is the best time to prune roses to ensure a good display at the beginning of June and give them mulch with well-rotted manure. Plant herbaceous perennials and alpines, and their roots can be lifted and divided. Root cuttings and cuttings of any basal shoots 7cm/3in or more in length should be taken during March or early April. Tidy and weed the beds.
Pinch out the ovaries (the swellings behind the flowers) of daffodils and other bulbs as soon as the blooms are dead, but allow the leaves to continue to grow undisturbed. In dry weather, flowering bulbs will need watering and give them a feed with quick-acting fertiliser to help build up the bulbs for next year.
Plant the first gladiolus corms from the middle of the month and then in fortnightly succession until mid-April. Dahlia tubers for propagation should be brought into a temperature of 10°C/50°F, placed in a box and sprayed daily with water which has been allowed to stand at the same temperature over night to encourage the production of shoots.
Place curtain netting over peaches and nectarines grown against walls as this will protect them from several degrees of frost. Start tieing into place raspberries, blackberries, loganberries and tayberries as the canes develop. Hoe around the roots of trees, and hand-weed soft fruit whose roots are near to the surface and liable to be damaged.
The temperature should be about 10°C/50°F for growing on seedlings sown last month and for germinating most spring plants. Half-hardy and hardy annuals to be sown in the greenhouse include ageratum, alyssum, antirrhinium, asters, annual chrysanthemums, cosmos, gaillardia, helichrysum, lobelia, nicotiana, petunia, phlox, rudbeckia, salpgilossis, salvia, scabious, tagetes, verbena and zinnia. Start cannas and begonias into growth. Once growing, pot them up in an open compost.
Repot conservatory and house plants into larger containers, dividing where necessary. Water those kept dries over winter; increase water given to other house plants. Continue to feed hippeastrums and other bulbs.
Sow tomato seed for growing outside. Plant out tomatoes, cucumbers and peppers into the frost-free greenhouse.
The pond will spring back into life, with frogs and toads spawning, and the fish will begin to take their first food after the winter fast. At the first opportunity before the pond has a chance to start a new yearly cycle, drain off half the water, which will remove most of the toxic materials that have built up over the winter. Fill with water from the rain butt. Continue to remove by hand any
dead vegetable matter. Commence planting bog plants in the water garden.
Complete the planting of deciduous trees while still dormant. Now is the final chance for winter pruning. Evergreens should be examined for signs of weak or misshapen growth, or for storm damage (cut the branches out at their origins).
Harvest and remove the remains of winter greens before they run to seed, digging the ground as it becomes vacant. Sow seeds of early peas, carrots and radishes (to advance the crop, these may
be sown under cloches), and also lettuce, maincrop parsnips, salad onions, and also summer cabbage.