Right now in this month of abundance there seems to be plenty but all too soon the surpluses will disappear and we will fall back on our stores. In an ideal world we plan to have succeeding crops without error or omission -but in practice we as often forget. We seem very keen to get the earliest tomato to ripen, the first sweet peas or apples, but then we omit to give as much value to the last tomato, the last courgettte or final picking of French beans. Obviously many crops are grown and once ready can be stored for use as required but these still lack that essential freshness that only the just plucked possess. The actual harvest for every crop does not need happen all at once, it may wait and with cunning can often be extended for quite a bit longer.
Traditionally with many vegetables and even more so with the salad crops we use staggered sowing dates to ensure a continuity of cropping. Indeed even with crops where only one batch is required it is prudent to sow three and to select the best. (Surprisingly sowings made as little as a couple of days apart may vary widely at maturity.) Otherwise those crops that stand and keep in fair condition such as cabbages and many roots are rarely sown succesionally, though younger specimens might be more enjoyable, the extra effort is too much.
More commonly sown successionally are peas and beans, sweet corn, beetroot, and all those leafy salad crops. But we have such a tendency to concentrate on the earliest crops we often neglect the later possibilities. True we may run out of space and moisture so later sowings could be handicapped but often space does come available and water could be applied, it’s just we forget with so much else to do. Of course each crop has a fixed window we can’t much alter and it is no good making sowings way outside the possibility of a successful harvest. But with a suitable choice of variety almost every early summer crop can be harvested for a longer period and many succulents such as Chinese cabbage, pak choi, spinach, Florence fennel and many of the lettuce do much better from sowings made after midsummer anyway.
Of course sometimes later successional sowings catch up with earlier ones and crop at the same time so merely sowing later does not always extend the harvest. However another way to spread the cropping is by giving some of the plants from a sowing a check through transplanting. Each time we move a small plant we check it and set back the harvest by a few days or longer. If a batch is split in thirds, one not moved, one moved once and one lot moved twice then we usually find that they now mature over a much longer period. Unfortunately not all crops can be transplanted as it may make some bolt especially in hot dry conditions but with care many can be. Indeed with just a few this can be done at a very late stage just to gain a little more time. For example summer cabbages and cauliflowers can be lifted when ready and simply replanted in a cool moist spot where they will stand ready for up to a week or two.
Naturally growing plants in a shady cool place tends to make them slower than those in full sun and we use the north side of a wall to advantage -though more often with fruit than vegetables. Most soft fruit and some varieties of top fruit will grow happily on a cool north wall but ripen weeks later than those in the open and even later still than those forced into early growth by a warm south facing wall. The fruits shade produces tend to be less sweet and have more acidity which may make some more palatable as dessert and good for preserving.
Extending the growing season at the front end by going under cover is widely practiced with cloches, coldframes and greenhouses all being used to bring on the plants and to force earlier crops. But we forget we can do the same at the other end of the season. It is true that the bigger plants then are harder to house than the small seedlings and so on that we tend in spring. None the less by using cloches we can extend the life of cropping of such as tomatoes, French beans, courgettes, tender salads and even strawberries by several weeks. This is especially so in years with mild autumns and only a light early frost or two. If we can either move our crops under cover or apply a protective cover to them such as fleece we can keep off the cold and gain a few weeks more fresh produce. Of all the methods of extending the season this is one of the easiest yet most often neglected.
I am a great enthusiast for the Orchard House method of forcing early fruit. The bushes or trees are pot grown and kept outdoors all winter and are then brought under cover in very early spring. The sudden warmth shocks them into early and productive growth for very early crops. By either having a selection of varieties or by bringing in the same variety in several batches the cropping season can be extended at the front end easily. However by keeping the trees and bushes in a very cold place such as a refrigerated room (cold stores are available commercially for similar purposes but us amateurs have to box clever -grapevines and strawberries in pots can go in the household fridge with ease (providing your partner does not object to the intrusion)) then they can be kept dormant and only kicked into growth when brought out. This can be done so that they then crop later than even those grown on a cool wall. Such a method has especial benefits to those growing in the milder regions where crops of cherries, pears, strawberries and so on are hampered by the soft winters and springs and can be won by using an artificial cold winter then bringing the plants out for summer and autumn.
Some crops can be persuaded to give a bonus- salads such as the cut and come again loose leaf lettuces and saladings such as rocket can be cut close over and then given a heavy watering and liquid feeding which usually kicks them into gear again producing new flushes of succulent leaves. This can also often be done with broad beans which if picked clean early on will give a late picking if cut back and regrown from just above the roots- far later than any sown crop would do. In a similar way it is possible though not highly efficient to gain bonus crops from peas, sweet peas and most other beans however these do not respond quite as well as the broad beans. (It is crucial to regularly pick these crops clean as leaving any seeds to mature stops the plants throwing more flowers, this is also true for the courgettes, gherkins, marrows and squashes all of which carry on cropping longer if kept picked) Even an asparagus bed can be encouraged to throw some new spears by feeding and watering- too few for commercial use but great for treats for yourself.
The cabbage family have another trick that used to be widely practiced but has fallen into disuse and that is to gather the cabbage head and then to cut a cross in the top of the stem. This (if the plant is fed and watered well) will cause the roots to throw three or four small cabbages from around the cross. The Broccollis naturally produce side shoots but again more of these are produce if the stem is cut with a cross. This trick rarely works with true cauliflowers but does with pak chois which can be encouraged to form several mini-heads if so cut after the main head has been taken. Cabbages and caulis can also be dug up roots and all and hung upside down in a cool shed or better still a covered cool trench where they will stay in good condition for up to a week or two, more if their feet are wrapped in a wet cloth. You do not even need cut a whole cabbage to bring in; it is simple to cut half a cabbage (almost vertically) for use leaving half attached to the roots and covering the cut surface with foil or film. It will stay fresher attached to the plant than if gathered and put in the fridge. And most everyone knows that to break the leaves on a cauli and to bend them over the curd will keep it whiter and more succulent than leaving it exposed to the sun.
One very economical trick is to be very careful when lifting potatoes that have not fully died down. The haulm and roots are gently lifted so as not to detach any of the smallest tubers that have not swollen much, by replanting the haulms together in a trench and watering them they can be coaxed into giving up their goodness to the wee spuds which swell as the haulms wither giving a small bonus crop.
Protecting ie not harvesting but guarding the crop in situ is approaching our normal storage but again can be used to extend the harvest. Some crops such as carrots and cabbages can be covered with a layer of straw and fleece not to so much to keep the winter cold off but to keep the autumn heat off stopping them going over as quickly. Some fruits hang on the bushes for weeks or even months and are threatened more by the birds, wasps and weather than by going over. Red and white currants will hang well into October if the wet and pests are simply kept off them. Grapes can be covered in paper bags which keeps the pests and some wet and sun off them so they will hang for many weeks longer –though in damp years the mould gets them instead!
And if by chance the autumn comes early next month with hard frosts then don’t forget to gather in the tomato plants roots and all, hang them upside down in a frost free shed and you can be gathering ripening fruits for months to come.