Often excluded from works on fruit as they’re annual, soft and herbaceous not perennial and woody. And even though used most in savoury dishes they’re none the less fruits. Indeed they’re some of the most important fruit crops to the kitchen gardener.
Although cucumbers and aubergines are ancient they’ve not been much grown till relatively recent times. The others, from the New World, are also much more grown now than previously. The main reason is their relative tenderness. The introduction of cheap glass structures made these so much easier, modern plastics more so. The electric propagator has further increased their ease and popularity. Starting under cover in the warm allows us to extend their season long enough at the beginning to make them practical propositions. Although a light crop could be gained many years from seed sown outdoors when soil and weather are warm enough it’s rarely worth the space or effort for any but the faster squashes. Buying in or starting plants off early is a more effective approach. Breeding has helped as modern varieties are quicker to mature and heavier cropping. Heirloom varieties may have great taste or interesting attributes but they’re nowhere as easy to crop as most modern ones. Indeed the latest varieties really have to be recommended both for their reliable cropping and for their disease resistance.
Tomatoes are closely related to tobacco, peppers, aubergines, physalis and potatoes. All belong to Solanaceae, a family nearly always containing toxic alkaloids but of immense economic significance. This large family of closely related cultivated crops has meant many pests and diseases found them good prey. Such as aphids and whitefly swap from one to the other with alacrity, and the potato blight can damage or even wipe out tomato crops. Never the less tomatoes are one of the most popular amateur crops. Although they really do best under cover most people can manage an outside crop most years with a suitable variety in a sunny spot. As blight has become such a frequent occurrence then the sensible varieties are those offering some resistance. Legend, Histon Cropper (a sprawling bush) and Ferline have proved best for me and the delicious Gardener’s Delight is always worth trying. Indeed smaller tomatoes crop quickly and although not blight tolerant give many usable fruits whilst bigger fruited varieties such as the divine Marmande mostly go to waste. The Italian plum shaped such as the Roma series, San Marzano and so on are not exactly blight resistant but manage to crop despite it most summers and are recommended, especially for freezing or bottling for winter dishes. Growing under a plastic flysheet to keep off rain prolongs the blight free period by weeks and usually allows a crop to be snatched before the plants fail, it may also keep off light frosts after planting out. However growing under real cover is more reliable, allows a wider range of varieties and gives both earlier and later crops. Tomatoes, like the other Solanaceae, prefer glass to plastic as they like bright light. Dimmer conditions give poor growth, less yield and makes them more prone to mould. Adding more heat to dim conditions does not make things much better either. Indeed tomatoes want bright hot days and cold nights so steadily heating a greenhouse much beyond frost free may be counterproductive. Another important point to watch is feeding and watering. Both are required, in moderation, more so if in pots or containers. However over watering or over feeding results in rank growth and lessens quality. Ideally give enough of both to keep the plants growing well but not lushly. Once the fruits are forming more potash is more useful than more nitrogenous feeds. The ‘tea’ made from rotted comfrey leaves used well diluted is the commonest homemade tomato feed. However I find borage tea better. It’s less inclined to make the leaves yellow from the high potash levels inducing chlorosis from magnesium deficiency. Tomatoes also need their growth re-directing by removing side-shoots, failure to do so with all but the bush varieties results in excessive congested growth and poorly ripened crops of diseased fruits. Early on the pinched out side-shoots may be potted up for more plants; these are squatter, fruiting lower and sooner than others grown from seed. For earliest fruits sow a cold tolerant quick variety such as Stupice very early, say January, in warmth. Then keep the plants poorly fed, under-potted and only watered enough to stop wilting, preferably up on the staging. As soon as the first flower truss has set (hand pollinate even if thought unnecessary) remove the top shoot a leaf above and any side shoots. You will be amazed how quick those first fruits swell. To speed ripening keep them exposed to the sun placing banana skins nearby for their ethylene which reddens them earlier. Do not leave ripe fruits on as this suppresses more setting. Treat main crop tomatoes less severely but still remember you’re after fruits not leaves. And do support them well as dropped ones cause much trouble. Do not reuse strings or canes as these harbor problems. There are countless greenhouse varieties bred for very good disease resistance, Matina, Moravi, Matador and so on, and others for flavour, and colour, the choice is huge. Beware- big beefsteaks only get really big if you ruthlessly limit the numbers left on each plant.
Sweet Peppers are in many ways easier than tomatoes if you can satisfy their major requirement which is a bit more warmth. Outside crops do poorly, their fruits blacken if a little cold or windy whilst greenhouse plants crop much better for much longer. Kept them warm and dryish in autumn to stop mould and fresh peppers can hang on until after Christmas withering a bit towards the end. Started off early and grown on much like tomatoes these are slower to mature than tomatoes but can be used green as well. (Red, orange or purple peppers start off green colouring when ripe.) Peppers need even less feeding and slightly more careful watering than tomatoes (avoid water-logging them). Oddly when grown in pots peppers exhibit an unusual effect especially in black plastic and or in full sun. Their roots refuse to enter the very warm compost on that face of the pot. Thus I shade pots with other squatter plants or simply a piece of foil. Larger fruited and heavy cropping varieties need staking or tying up. Do pick ripe fruits as again leaving them on suppresses others setting. Watch for slug damage! Hot peppers are much the same as sweet peppers with one major difference. The sweet are predominantly bred from an annual species and almost always cease cropping and die in winter. The hot are bred from several species of short lived perennials which also have lower temperature requirements to continue cropping than tomatoes or sweet peppers. Thus it’s possible to keep hot pepper plants alive and cropping through winter and into the next or even several years. Their variety is endless, and the hotness highly variable. Smaller often means hotter. Habanero ones especially Big Sun are my favourites. Both sweet and hot peppers are easily dried and stored.
Aubergines are grown and treated almost exactly as peppers. I’ve never grown a decent crop outdoors. All other points apply, especially on removing ripe fruits, preferably before they get too seedy, and beware the small spines around the fruit neck. However while with tomatoes or peppers there are many sizes, appearances and also tastes I find little difference in the taste of most aubergines. They’re blandly interchangeable, though smaller ones are wasteful with too much skin to flesh. Beware; aubergine surpluses are hard to find much use or worthwhile storage method for.
Cucumbers fall into three camps; the old, the new and the outdoor. The old are obsolete with a few exceptions such as the spherical Crystal Apple. The new are expensive seed or plants but worth it for their vigour, cold resistance (still needing it warm though), disease resistance and most of all being all-female. Pollinated indoor cucumbers become bitter. (And leaving any cucumber on to swell and yellow stops all others forming even killing the plant.) These new varieties can be started in warmth in the New Year to crop by Easter, and crop they do, especially the smaller fruited ones. Their major problem is cold damp with rotting off at the neck thus the old plan of planting on top a mound and careful watering. Cucumbers do not fare well with tomatoes preferring diffuse less bright conditions under plastic rather than glass, all other things being equal. Their stem needs supporting but side-shoots do not need removing and can increase their cropping area. Feed and water regularly as the srtems lengthen. When plants get too straggly root their tips and grow these on for replacements. The outdoor varieties, and gherkin sorts, are different; not going bitter when pollinated, usually have tiny prickles on their skin and are sown much later, say a month or so before the last frost, in warmth for planting out. Essentially straightforward their only common problems are a cold summer, or leaving a fruit on to ripen!
Squashes are the easiest of all the vegetable fruits, mainly because they’re the quickest. Even so they find cold wet summers hard and unproductive. Under cover they’re too hot, suffer red spider mite dramatically and produce mostly male flowers. Thus they’re best started indoors a month or less before the last frost, or sown in situ in pre-warmed soil. A clear plastic sheet on sticks above a black sheet spread on the ground for a fortnight before works nicely and may be retained until the plant has grown away. Enriching the soil beforehand is more important than for other vegetable fruits and regular feeding is almost obligatory, as is liberal watering. No pruning and rarely pollination are needed although that may help with the first flowers. Huge crops can be thrown in a good summer, little in others. Choose your varieties carefully, some are grown for their nutritious seed, others such as Spaghetti for it’s stringy flesh. Summer squashes as with pattypans and courgettes/ zuchinni do not store well, so must be picked young and continuously. Others are more pumpkin like; keep better storing well into winter if matured on the vine then kept dry and warm. Butternut varieties are most popular. The Hubbard and Crown Prince sorts can keep up to a year, I’ve had last year’s fruits still available as the current year’s crop comes ready.