Guide to Growing Vegetables|Vegetable Garden
Vegetables are a diverse collection of plants, mostly annuals or biennials, grown for their edible parts. Almost by definition, they are usually eaten cooked, although a group, commonly distinguished as salad crops, is eaten raw. The name vegetable, although implying some vegetative (non-flowering) part of the plant, is a loose term and many of the crops that are eaten as vegetables (peas, beans,, egg plants, and the many members of the family, for instance) are botanically fruits while some, such as cauliflower and globe artichoke, are immature flowerheads. There are relatively few perennial ; the most important are asparagus and rhubarb (which, ironically, is sometimes considered a fruit, although here it is a true vegetative part, the stem, that is eaten). A large group of unrelated crops – turnips, onions, potatoes and Jerusalem artichokes among them – are grown for their edible roots or other underground parts.
The ideal position for vegetables is in an open spot that attracts maximum sunlight, but is sheltered from the most severe weather. Frost-pockets should be avoided and, in exposed areas, some shelter in the form of a hedge or windbreak is advantageous. Few gardens have the deep, rich, yet free-draining soils described as pre-requisites for vegetable growing in old gardening books, but fortunately almost all soil types can be improved by good cultivation and the addition of bulky organic matter, especially animal manure or well-made. If your soil is shallow, root-crop growing will be especially difficult but contained with boards and filled with well manured soil will allow most types to be grown successfully. A pH of around 6.5 (slightly acidic) is ideal. Soils that are more acidic than this, can be improved by the addition of garden lime.
A standard allotment garden, of roughly 250m2 (300 sq yds) was once regarded as the minimum that could keep an average family self-sufficient in vegetables. But few gardeners today either can or would wish to devote this amount of space to vegetable growing. If you buy, rather than grow, bulky crops such as potatoes (especially main crop potatoes) and cabbages, and concentrate instead on high-value and high-yielding crops, a plot of roughly 100m2 (120sq yds) should make a significant contribution to your home’s vegetable requirements. Plots smaller than this are still valuable. But here it is advisable to concentrate on those vegetables and salad crops that really are best when harvested fresh.
Sowing and planting
Almost all vegetables may be sown directly into the position where they are to grow, using the technique for hardy or half-hardy annuals. Early in the season, or on cold wet soils or in exposed areas, there are distinct advantages in sowing hardy vegetables under protection (in a greenhouse or cold frame) into 8cm (3-1/4in) pots and transplanting the young plants four or six weeks later. With half-hardy vegetables such as runner beans, sweet corn and, for instance, you can gain many precious weeks by starting the seed in warmth. A few vegetables, most notably root crops like carrots, parsnips and beetroot, can’t be successfully transplanted but a comparable advantage may be gained by covering the newly-sown seeds with cloches.
The theory of, whereby related plants are grown together but on a different part of the each year over a three year cycle (right), is based on sound scientific principles. It is designed to ensure that the soil’s nutrient reserves are used to the full and to help prevent serious pest or disease problems building up in the soil. But the principle was designed for commercial practice; I have reservations about the usefulness of such a system on a small home garden plot. Moreover, many gardeners don’t want to devote equal areas to peas and beans, root crops or brassicas and may prefer to grow more of the crops such as lettuce, spinach and courgettes that lall out-side the conventional rotation groups. My advice is to use a rotation scheme in so far as it fits in with other constraints, but not to consider it a Holy Grail.
Like all plants, vegetables suffer from pests and diseases. Most are minor nuisances, however, and their effects merely cosmetic. Many problems can be avoided by a combination of garden hygiene, healthy seed stock and non-chemical preventive measures, for example, garden mesh will protect many crops from airborne pests. Among the problems that can cause significant loss of yield are potato blight. Cabbage root fly, fruit rots and carrot fly, while white rot of onions, club-root of brassicas and some nematodes are particularly insidious by virtue of their long persistence in the soil.
Feeding and watering
Without feeding, most crops will be disappointingly small. Each vegetable has different requirements and, for the sake of simplicity, I have divided them very roughly into three groups: those requiring low, medium and high levels of a general-purpose fertilizer. These equate approximately as follows:
Growmore or, blood and bone
Low < 130g/m2 (<4oz/sq yd)
Medium 130-275g/m2 (4-8oz/sq yd)
High > 275g/m2 (>8oz/sq yd)
My preference is for the organic-based fish, blood and bone, though the artificial Growmore will give equally good results. Some gardeners who opt for the completely organic approach attempt to rely entirely on bulky organic matter such as well rotted manure or garden compost but very large quantities are needed to satisfy the crops’ entire nutrient requirements in this way.
Water should be used economically. Always sow into moist soil and water in transplanted crops thoroughly. Thereafter a simple rule is only to water when the edible part of a crop is maturing. Therefore, water beans when the pods are setting, potatoes when the tubers are swelling and cabbages when the hearts are forming.
The main advantage ofis that you can harvest each at its peak and eat it immediately. In the descriptions below I have indicated the age at which each type of crop can be expected to mature. In mild areas or abnormally favourable conditions these periods may be shortened.
Some vegetables are worth growing not just to be eaten fresh, but to supplement shop-bought produce during the winter months. The simplest and most economical method of storage is to leave the produce in the ground, and a surprising number of crops respond well to this. A few vegetables are worth freezing (sometimes after blanching) and several more can be successfully stored dry in a cool outbuilding.