‘Cut and Come Again’ Vegetables and Double Cropping
Is it worthin a small or very ? For those vegetables which take up a lot of room for many months — Brussels sprouts and maincrop for example — the answer is probably no. But where you can grow something tastier, fresher and different from anything you can buy, the answer is probably yes. What is certain is that if only a small area is available for vegetable growing, it pays to adopt space-saving techniques.
In the typical English kitchen garden, vegetables are grown in orderly, widely spaced rows. It has not always been so. In the old days vegetables were grown closely, evenly spaced, in compact beds the width of ‘a man’s stretch’, about 150cm (5ft). Where necessary,between the plants was done by hand, though when plants are grown close together they eventually form a canopy which stifles most weed growth.
With the advent of the horse-drawn hoe market gardeners adapted their planting systems to the new technology and changed to our modern, widely spaced rows. They were copied by kitchen gardeners, albeit using hand hoes instead of horses. But today the pendulum is swinging back. Now vegetables are being grown on a field scale on farms, where the tractor is the tool. So farmers are reverting to a bed system, this time with beds of a width that a tractor can straddle, and, once again, plants grown closely at equidistant spacing within the bed.
This highly productive, intensive form of cultivation deserves to be imitated by space-starved amateurs. For modern research has shown that with many vegetables — carrots, , runner beans for example — growing vegetables at equidistant spacing in narrow beds or patches produces higher returns from any unit area of ground.
One factor which determines the spacing is the size of vegetable required. Take onions as an example: they can be sown or thinned to 1cm (1/2in) apart to get pickling onions, 2.5cm ( 1in) apart for green salad onions, 4cm (1-1/2in) apart for medium-sized cooking onions, 5-7cm (2- 2-1/2in) apart for large onions.
Many vegetables benefit from being grown fairly closely together in patches: closely spaced self-blanching celery, 20cm (8in) apart, becomes more blanched;, 30-35cm (12-15in) apart, will be cross-pollinated better when planted in a block; tomatoes, 45cm (18in) apart, and onions will ripen earlier; while , dwarf , both 22cm (9in) apart, and even , locm (4in) apart, provided they are not too tall a variety, will to some extent hold each other up, so requiring less supplementary support. In all these cases space is saved.
‘Cut and Come Again’
Patches are also the ideal format for the various techniques bracketed under the general heading of ‘cut and come again’, which are so productive and useful for. Provided the is reasonably fertile and there is adequate moisture, many vegetables will re-sprout after being cut. At one extreme, can be cut off and will burst into growth again; at the other the hoary old stump of a which has been cut in spring or early summer will, if a shallow cross is made in the stump, produce in due course four or five more heads, crammed together on the old stump.
In the past, seedlings of , , turnip, radish and , to name a few, were sown broadcast in the garden. The leaves were cut when only a few inches high (their most nutritious stage, incidentally) for use in salads. This is still done on the Continent with plants such as lettuce, , Mediterranean rocket, even , which is cut when 10 or 12cm (4 or 5in) high. Most of these re-sprout to give a second, sometimes even a third or fourth crop, from the original sowing. The sheer weight of leaf which can thus be obtained from a small area is astonishing.
Using this principle, a method of growing non-hearted ‘leaf lettuce’ has been developed recently by the National Vegetable Research Station (NVRS). They use certain varieties of lettuce (‘Lobjoits Cos’ and ‘Paris White Cos’ are two of the most suitable) and sow seed in drills about 12cm (5in) apart, aiming at twelve to fifteen seeds per 30cm (12in) run. This close spacing prevents the formation of a hearted lettuce; instead the plants form crisp, upright leaves. The leaf is cut about 2.5cm (lin) above ground level when 10-12cm (4-5in) high, the plant being left to re-sprout.
It normally takes about eighty days for a hearted lettuce to form, but a far heavier crop of leaf lettuce is ready for cutting within forty to sixty days (depending on the season), from a far smaller piece of ground. To keep a family supplied with leaf lettuce from May until October the NVRS blueprint recommends small sowings at weekly intervals during the first four weeks of April and May, and again in the first three weeks of August, cutting each crop twice.
Many plants, ranging from salad vegetables to some of the more unusual brassicas such as Chinese cabbage and Japanese mustard, andand when grown for ‘tops’ in spring, respond well to the cut and come again treatment. Of the salads, broad-leaved , ‘Sugar Loaf’ chicory (which forms a tightly packed conical head of crisp leaf), the red Italian chicories, Florence fennel and some lettuce, especially the ‘Salad Bowl’ type, are the most suitable. The stumps left in the ground after the main head is cut will shortly throw up a second crop of smaller but useful leaf.
This is particularly valuable during the colder months of the year; indeed, a few plants transplanted or sown in a cold greenhouse in late summer or autumn for cutting may continue growing in mild spells during the winter. These trimmed plants seem able to survive lower temperatures than they would if larger and leafier.
Where conventionally spaced rows are used, space can be saved by various forms of double cropping, such as intersowing, intercropping, or undercropping. In most of these cases a quick-growing crop is combined with, or grown very close to, a slower-growing, space-consuming crop. The idea is that the former has matured and is harvested before the space is required by the latter.
One of the best candidates for intersowing is the slow-growing parsnip. Parsnip seed can be ‘station sown’ at stations about 15cm (6in) apart along the row, with pinches of radish seed, or dwarf lettuces such as ‘Little Gem’ or ‘Tom Thumb’, sown in between. Radish seed can be mixed with onion, , parsnip or carrot seed and sown in the drill with them. Because it germinates so much faster, radish helps to mark the rows (making weeding easier early on), also providing a quick crop long before the main crop will be ready.
Brassicas such as and Brussels sprouts have plenty of empty space around them when first planted, and at this stage can be intersown, or interplanted, with, say, salad plants or, again, . They are also good subjects for intercropping: for example, they can be planted out in early summer between established rows of peas, and although they will be overshadowed at first by the peas, these will be over and cleared within a few weeks, leaving plenty of space for the brassicas to develop. If they had had to remain in the seedbed until the peas were finished several growing weeks would have been lost.
Sweetcorn is the best crop for undercropping as the lower leaves dry off as the crop matures. This means that plenty of light can penetrate the ground beneath, so that trailingand pumpkins, dwarf French beans, lettuce and many other plants can grow happily beneath.
With any form of double cropping, soil resources are being fully stretched; so the soil must be fertile. If rainfall is low, the crops may need extra watering so that both can develop fully.