No garden should be without tomatoes

March is one of the busiest months for vegetable growers and one of the most rewarding. There is nothing quite as satisfying as seeing rows of seedlings appearing in just a few days.
Set out seed potatoes in trays and stand in a cool, bright position for shoots to form. Early varieties can be planted in March, but plant main-crop potatoes later in April.
As the weather warms, beware of slugs and snails. Catch them before they begin eating new shoots. A good time to spot them is at dusk.
Crops to sow outdoors or under cloches include broad beans, beetroots, Brussels sprouts, summer cabbages, leeks, lettuces, hardy peas and radishes.
Tomatoes are one vegetable no garden should be without, and many varieties can be grown outside in summer, with some even thriving in patio pots or hanging baskets. The earliest crops will develop on plants grown under glass, ideally in a heated greenhouse, but an unheated one will do. Tomatoes are easy to grow from seed, so start sowing now to raise indoor varieties. Sow in a heated propagator to encourage quick germination or grow on a windowsill. To raise outdoor varieties, sow later in March, potting on as plants grow. Plant them out in early June. Sowings can be made in April, but plants will flower and fruit far later than those that were sown earlier.
Plant shallot sets in March, spacing them at 15cm (6in) intervals in rows 30cm (12in) apart. When the conditions have warmed up in late March, onion sets can be planted out into a firm seedbed. Cover rhubarb with forcing jars or old buckets to exclude light and encourage long tender stalks.