Advice for beginners by Adrian Hill
March marks the start of the outdoor vegetable growing season. Over winter you may have prepared the ground, sowed broad beans and put in onion sets as recommended by David Smart in his article in the Winter issue but generally the soil will be too cold and wet at the beginning of the month to do much outside. To get a good start for the vegetable year, this is the time to sow lettuce and tomato seeds over heat in a propagator in a greenhouse or on a window sill and, if they had not been overwintered, broad beans. The lettuce and broad bean seedlings can be planted out later in March; the tomato plants, after transplanting into bigger individual pots (3.5 inch diameter), not until mid-May after the risk of a late frost. Except for trailing varieties, tomato plants need supporting canes to which they are tied. The side shoots should be pinched out when small and only two or three main stalks retained.
Digging is nowadays a controversial topic with many gardening writers advocating a no-dig approach. Personally, I favour digging to improve the drainage and consistency of the soil and to incorporate humous in the form of compost or manure to a depth of about 9 inches. In much of London yellow clay lies less than 12 inches below the surface and it is therefore best to do shallow digging to avoid bringing the clay to the surface. Clay is quite fertile but heavy to work and tends to produce deep cracks in dry weather allowing any watering to sink below the roots of many vegetables. If no digging has been done it will be necessary to prepare the surface before sowing seeds or planting out seedlings by breaking up the surface with a spade to a depth of about two inches, scattering on this some fine compost and and then raking with a strong rake to make a fine tilth.
For an interesting choice of vegetable varieties it is advisable to get a good seed catalogue; these also give advice on the cultivation and characteristics of the chosen plants. Good examples are Dobies (www.dobies.co.uk/0844 701 76230) or Marshalls (www.marshalls-seeds.co.uk/01480 44 33 90). English seed merchants these days can be very parsimonious on the quantity of seeds in a pack; Italian and French seed merchants are much more generous. A good selection of Italian seeds (Franchi ) is available from the Croxted Nurseries in Dulwich.
Before planting anything it is a good idea to sketch out on a rough plan the approximate position of the various crops you wish to plant. If the early maturing plants are removed after harvesting it is possible to replant the vacated space and have a second crop in the same place in the same season. Early crops that can be harvested by the end of July include lettuce, peas, dwarf beans, courgettes and early potatoes. These can be followed by beet-root, spinach, swiss chard (Bright Lights for a colourful display), leaf chicory and brassica (cabbage family), including quick maturing varieties of cauliflower such as Purple Graffiti, which if sowed in pots in June and planted out as seedlings in late July will produce fine purple cauliflower heads before the first heavy frosts usually not before December in London. Cavolo nero (black Tuscan kale) is a very hardy brassica and will usually survive the harshest winter to produce delicious tender shoots in the early spring. Before then the larger lance-shaped leaves can be food processed with pine nuts, garlic and olive oil to make an excellent substitute for pesto sauce for spaghetti. Many varieties of leaf chicory (such as variegated Castelfranco) are also hardy (though whether they survive the harsh weather of early January this year remains to be seen) and make excellent crisp winter salading, slightly bitter, but often very attractive in the salad bowl with red veining in the leaves.
Most gardeners with an allotment or a decent sized vegetable plot in their garden will wish to plant main crop potatoes, carrots, cabbages, leeks and onions. Some may say growing these vegetables yourself will not give you anything better than you can buy in the shops, but this overlooks the satisfaction and pride to be found in growing these basic vegetables yourself and the fact that you can know that poisonous pesticides and herbicides have not been used on them. Nevertheless, there is a lot to be said in favour of concentrating on vegetables where the freshness and flavour of just picked produce is distinctly better than anything that can be bought, such as sweetcorn, tomatoes (allowed to ripen on the plant), beetroot (including white, golden and red and white ringed (Chioggia) varieties), peas and all types of green bean. For peas a very good choice is snap peas which can be eaten pod and all when young and later very sweet peas with the pod discarded; they can be obtained in both dwarf and tall varieties, the later needing a supporting net. Winter squash (pumpkin family) are also worth growing and fun. A very good variety is Crown Prince which has a much better flavour than ordinary pumpkins and, after harvesting in autumn, will store well until March without losing its sweet flavour.
Soft fruit is also a good choice. Home grown strawberries, picked ripe. can taste a great deal better than bought specimens and if early, mid-season and late varieties are chosen can be cropped over a long period. Strawberry plants lose vigour after two and a third of the strawberry bed should be replanted each year, removing the oldest first. Most varieties produce runners which can be spread out about a foot from the mother plant and anchored down with hair pins in late summer/autumn to produce strong plants for the following season at no extra cost. Other rewarding soft fruits are red and black currants, raspberries and raspberry/blackberry hybrids such as tayberries, but these all fruit on year old wood so there is little to pick in the first year after planting, though autumn fruiting varieties of raspberry will produce in the first year after winter planting.
Most fruit and vegetables can be frozen to extend their season of use, though defrosted strawberries and raspberries can only be used for sauces or jams. Tomatoes freeze well as whole fruit, without sticking to each other, but again can only be used for sauces or soups when defrosted.
Many people will of course not have gardens large enough to cultivate for many vegetables and allotments in the Dulwich area are currently difficult to obtain, with two year or more waiting lists. This does not rule out grow-your-own as many specimens can be grown in tubs or planters on a patio. This includes lettuces and other salad crops, dwarf beans, tomatoes, herbs and such like. Pot and container grown plants will however require more watering in dry periods than plants grown in the open.