This section is from the book "The Gardener V3", by William Thomson. Also available from Amazon: The New Organic Grower: A Master's Manual of Tools and Techniques for the Home and Market Gardener.
In most gardens, large and small, there is abundance of salad material during the summer and autumn months, which is much valued by the owners; but the same cannot be said about quantity in all gardens throughout the winter and spring months. Then, in many instances, all kinds of both choice and common salad plants are very scarce, and often not obtainable. I do not mean to say this is always the growers fault, as we do not belong to that unreasonable class who expect gardeners to keep up a constant supply of everything whether they have the means or appliances or not; but by a little forethought, probably, more might be done in winter salads than we often see. There are many salad plants easily enough grown, others much more difficult, and only suited for those with the very best of accommodation; but what with one thing and another, nearly every garden might have a variety of salading in the winter time; and although many might think productions of the kind are most valuable during the hot weather in summer, they will generally be found as acceptable in the short days as at any other time. Cucumbers may be regarded as the worst to obtain of all winter salads, and they are about the most valued.
Their winter culture does not differ much, if any, from that necessary to grow them well in summer; but the want of sufficient heat in winter is the one great obstacle to their general culture at that season. Unless one can find a place for them where the bottom-heat will never be lower than 80°, and the atmospheric temperature 65° or 70°, their culture need not be attempted, as an unsatisfactory-crop or complete failure will be the result. With less heat than that above stated we have managed to keep them on until Christmas, but never for a whole winter. Where convenient means exist for their growth, the present is a good time to consider the matter. Next to having plenty of heat, strong plants well-established before winter sets in is the most important. These may be raised from seed sown in August, or plants may be had from cuttings. Of the two we prefer the latter; but in either case the young plants should be ready for their permanent quarters early in September. In summer, Cucumbers will grow in almost any kind of compost, but for winter, it must be rather light and open. The more fibre in it the better, and in putting it down it should be made into well-elevated mounds.
If planted early in September, growth will not be so rapid as at midsummer, but by the middle of October they will be strong plants, showing fruit; and if the foliage is kept clean, the roots consistently watered, and only a very few fruit allowed to swell at once, Cucumbers all winter may be depended on. For this, Telegraph is a variety we have never seen equalled.
Coming to more common and easier-grown things from the kitchen-garden, much salading may be had far into the winter, and sometimes right through it. Amongst these, Lettuce and Endive are always important. The two may be grown fairly well on almost any piece of soil. In summer, rich ground adds to their quality; but for autumn and winter, I think rather poor soil is best. In very rich soil they make much soft growth which cold and wet would soon cause to decay, but when grown more hardy, this does not so readily occur. Our winter Lettuce and Endive are generally planted on our south and other borders, after Potatoes, Cauliflowers, Carrots, Turnips, etc, and before sowing or planting we never put any additional manure after these crops. Neither do we dig or fork the ground, as firm ground is not so likely to cause watery growth. A hoe and rake over is all the preparation the ground gets. Of all positions we prefer a south border with a sharp incline for winter Lettuce. Here they always grow hardy and robust, and are not so liable to injury from the weather as in shaded corners. The seed of autumn and winter Lettuce should be sown at once, and another sowing in mild parts may take place a few weeks hence.
Sutton's Champion Brown, Hardy Brown Cos, and the green Hammersmith are the best winter Lettuce, and the Batavian and green curled are excellent Endives. The seed may be sown in lines a foot or more apart, and when the plants are large enough to transplant, a crop may be left in the seed-rows and the others replanted elsewhere. In frames, and under other kinds of protectors, are good places to put the plants which are drawn out. In such positions they may be planted without being protected from the first; but here they will be convenient when severe weather does come.
Along the bottom of walls are also good places for Lettuce, as they can easily be protected there. As a rule, Lettuce and Endive seed germinates very freely, and the young plants are frequently much injured through becoming too close in the rows before being thinned out or transplanted. This is a bad beginning for any Lettuce crop, but it is most felt by the winter ones, as they hardly ever quite recover from such a check. Sowing thin, and thinning in time, are two good ways of working. The after-culture consists chiefly in keeping the ground clean and open with the hoe, blanching and protecting in severe weather. When Lettuce are backward in folding in and blanching, they can soon be made to do this by tying up the leaves; and Endive must always be treated in this way. They should only be tied when quite dry, otherwise they soon decay. Protecting may be done in various ways. The safest is to lift the plants and place them in some dry, cool, dark shed. A month's supply or more may sometimes be treated like this, and others may be lifted and packed close together in frames where lights will keep them from wet, and where they can be opened up on fine days.
Full-grown plants, if lifted in this way and so treated, will prove most satisfactory; and it is astonishing the time they remain good when kept from frost and wet. Nailing two deal boards together in the shape of a V, and turning this over the rows, also affords good protection, and so does turning a flower-pot upside down over each plant; but about mid-winter, or in long spells of severe weather, they are most secure in frames or houses.
Radishes are another useful addition to our winter salads. They are very easily grown, and may often be had when other things have failed; and as they are generally eaten by themselves, they are very valuable for filling up gaps. The Chinese Rose is the best of all Radish for winter culture. The first sowing of it should be made early in September and again in October. The first may be in the open, the second in a frame under glass. The soil for both should be moderately rich, and not too heavy, and the position well exposed to the sun and light. Ours are always sown thinly broadcast, protected from severe frost, and fair gatherings are had from them all winter.
Beetroot is another excellent salad root, and it is so easily kept in winter that nothing need be said about that here. Celery, too, comes under this heading, and is equally well known. Mustard and Cress are others requiring winter culture. Heat and moisture will produce them anywhere or at any time. Small quantities may be grown in plates or saucers, more in cutting or seed boxes, and any quantity in beds in early vineries or suchlike. In November, when our first Asparagus roots are put in for forcing, we sow Mustard and Cress all over the surface, and it does well here without interfering with the crop, as the heads push up through it. Odd corners are the positions for Mustard and Cress.
Autumn - sown Onions are another good addition to our winter salads. As sown for the following year's culture, they are often too late to use in winter; but if a good bed of Giant Rocco is sown early in August, the produce will become a nice size for drawing throughout the whole winter.
Witloef, about which there has been much said in favour of its winter salad qualities, does not differ materially with us from the common Chicory. Those who grow the one need not have the other; but one or the other should be grown by all who have salad to provide in winter, as they are most useful for this purpose. As I stated some little time ago in the 'Gardener,' Chicory-seed should have been sown before now; but if put in at once, small roots would soon be produced that would give much useful salading in winter. The natural leaves die away in severe weather, and the roots may then be lifted and potted in clusters if placed in boxes, and set in any warm corner in mushroom-house, cellar, or other structure, when beautiful tender Lettuce-like leaves will sprout out and prove excellent for any kind of salad. Generally speaking, it will be found more satisfactory to have a succession of different things coming in in small quantities throughout the whole of the winter, than to have a large quantity of anything or everything in at one time, and nothing for long afterwards. In winter, everything should be drawn together as much as possible, and very small quantities of anything thoroughly well grown are more pleasing than an expensive quantity grown extensively and of an inferior description.