This is a month when changes in temperature and weather conditions can be expected both from day to day and from one part of the country to another. Warmth can now be felt from the sun which can result in weed seeds germinating. It is a good idea to attack weeds while they are young and, if the surface soil is dry, use the Dutch hoe to prevent them becoming established.

Mulching beds and borders is an effective way to control annual weeds and March is a good time to apply mulch or to renew or add to an old one. Some mulches such as chipped bark rot slowly and in so doing use up nitrogen thus taking vital feeding from the growing plants. Before mulching with chipped bark, make sure that the ground is moist and apply a dressing of Growmore fertiliser at the rate of 2oz/sq yd.

Sow seeds of summer bedding plants as well as sweet peas and they can be started off in individual peat pots to keep the roots from being tangled up with other plants. Then the sweet peas can be planted into the open ground later in the season, pots and all, to avoid root damage.

Seedlings and cuttings in the greenhouse or on a windowsill may require some shade on very sunny days when the sun's rays are increased by the glass. Temperatures can also drop like a stone at night, so give these seedlings extra protection from the cold, and if you can't supply heat, cover the plants with horticultural fleece.

When soil conditions are right, herbaceous border perennials can be divided and borders forked over before these perennials make a lot of new growth. Prune roses as soon as possible before this year's new growth is well developed.

Bare-root fruit trees and bushes as well as bare-root roses can still be planted, but make sure they are kept moist at all times so that they don't dry out.

Pot-grown bulbs, such as daffodils, narcissi and hyacinths will finish flowering and they can be planted out as soon as possible to encourage growth that will replenish the bulbs for future flowering. These bulbs are unsuitable for forcing again, so plant them in clumps between shrubs or herbaceous plants. They will flower again in two years' time and in future years.

Young plants in plugs become available in the Nursery at the end of this month, and if you have somewhere warm and light to keep them you can get a good start by growing them to a larger size. However, the roots of these tiny plants are very prone to drying out, so pot them right away.

To obtain new plants of specific dahlia varieties, it is necessary to take cuttings or divide old tubers. Take cuttings from new shoots on tubers. The cuttings will root more quickly in a cool greenhouse if the pots are placed in a large box covered with transparent plastic to conserve warmth and moisture.

Young fuchsia plants grown from cuttings will need repotting regularly so that the growth is not checked. Always use fresh compost and clean pots. John Innes No.1 is particularly good for this job. Keep pot size increase to a minimum as too much compost unoccupied by roots can turn the compost sour.

Prune summer flowering heathers by cutting the heads off the dead flower spikes which have protected these plants throughout the winter. Pruning too early risks damage from late frosts. Too late pruning delays flowering and can cause the heathers not to flower at all. If you don't prune, the plants become straggly and the life of the heather bed is shortened. Always cut off stems at the base of the flowers without cutting into old wood.