Nut crop

The Nuts as a group have one immense drawback to most kitchen gardeners- they generally make large trees. So far none of the true nuts is available in anything like as compact a form as say apples or pears, nor even plums. Indeed most nuts fit better the area beyond the kitchen garden rather than within. However the hazel family can, in theory, be constrained by regular pruning and sweet almonds are relatively small trees, which, if deemed worth the immense work load, can be trained on walls with their fruiting wood continuously replaced on the renewal scheme as for peaches. Still it is fair to say most nuts are big trees greedy for space more suited to orchards and woodlands, however not requiring much work they are also surprisingly rewarding.

Nuts are very rich in fats, minerals and protein, indeed producing more food value per sq.yd. than most other crops. They also come in their own stay-clean packaging, with a shelf life of many months if not years. In general nuts are not pruned much other than remedial repair and most do not need feeding or fertilising. In fact some do well on thin poor soils, or at least far better than other crops. They are not generally prone to pests or diseases and can be a relatively trouble free crop –well until the nuts are ripening then the bigger local wildlife and of course squirrels all become serious threats. On the debit side as well as their sheer size most nuts are slow to come into bearing, and most are wind pollinated so unfortunately need several individuals to ensure pollination. But on the plus side there is their timber which in some cases has special value, and their suitability for combining with livestock underneath giving the land dual use.

Alternatives- Now although resembling and standing in place of nuts in so many ways the Arachis hypogaea, peanut, monkey or groundnut is not botanically a nut. It’s to all intents a bean. The plants much resemble clover with yellow somewhat pea like flowers and are indeed, usefully, legumes. These can be cropped with some fair success under cover, preferably in the border because after the flowers fade their stems elongate and push them into the soil underneath. If you grow peanuts in pots the pods dangle over the sides and may not mature properly. Commonly a pair of seeds swell in each soft pod, some varieties have more. Some old varieties also trail or spread underground making clumps and so finding the nuts is much harder, modern varieties are usually more compact. Peanuts are worth growing for their nutrition, for their curiosity and to add more diversity to the crops under cover. Another nut that’s not is the Zulu, Tiger, Chufa nut, or Earth Almond, Cyperus esculentus, the bulbous tuberous root of a sedge with rush like leaves and a close relative of papyrus. You can grow this under cover in any moist rich soil and the remarkably sweet tubers can be eaten raw, dried or even made into conserves, they ripen in the autumn and although edible fresh are best dried. Gathering nuts in May may well be referring to Pignuts or Earth Chestnuts, Conopodium majus and Bunium bulbocastanum, which parsley like herbs are most easily findable when in flower during May and their small tubers, bits of swollen root, when cooked do indeed vaguely resemble nuts. These have potential development as nut substitutes for the smaller garden but valuable alternatives right now are sunflower and pumpkin seeds- there are even hull less varieties of the latter which are much easier to prepare.

The most compact true nut is probably the almond. This has often cropped well in the more southerly UK but as with peaches almonds become more difficult further north and west. However given a wall and methodical renewal pruning as mentioned above then almonds should be possible many more places. Unfortunately it is believed that if sweet almonds are pollinated by peaches or bitter almonds or even by some ornamental forms then their nuts become bitter not sweet. Thus almonds are usually grown away on their own. They suffer from peach leaf curl and are best kept dry from mid winter or treated with Bordeaux. Now I’ve not tried but I suspect you could probably grow sweet almonds in big tubs the same as for peaches. You could bring these under cover from mid winter and return them outdoors later to mature the crop circumventing the leaf curl and frost damage to the flowers (which always benefit from hand pollination anyway). Almonds need extracting from the pithy leathery fruit covering, they can be kept in the shell or shelled and packed in sealed jars to keep for several months. Usually the rough brown skin of the almond kernel needs blanching off in hot water to make it more palatable.

Much more suitable are the hazel and it’s relations. There are relatively smaller growing varieties of hazel, cob and filbert becoming available, otherwise these do make quite big bushes, too big for small gardens. However this family have long been coppiced and you will not kill a hazel by hard pruning so it’s possible to keep one constrained. The traditional form was to start with a very short trunk then to radiate branches as spokes of a horizontal wheel turned up at the rim to form a cylindrical wall of vertical branches which were then spur pruned. A challenge that. However systematic removal of the oldest branches, as well as congested shoots is sufficient, and pruned hazels kept relatively compact are more highly productive than when left to go to wood- the hazel poles and sticks produced from an occasional hard prune are useful as garden timber. Several varieties grown together crop heavier from more effective cross pollination. Filberts are possibly better flavoured than cobs but evicting each nut from it’s beard can be fiddly. Obviously the largest cultivated cob nuts are most convenient for picking etc. but the small wild hazels can be the tastiest if small. All the hazels are surprisingly productive on poor stony soils, do well further north and west than most other nuts and are good hedgerow croppers so these can be fitted to many sites otherwise unable to produce nuts. I have seen specimens (unhappy looking mind you) cropping in big tubs so that’s also possible. Additionally they can be obtained with truffles inoculated on their roots- after twenty years mine have not yet produced any though! The nuts once dried keep for a year, or more, especially if packed in dry salt.

Walnuts are unfortunately not small trees, and even though slow growing become huge in just a couple of decades as I have found to my detriment. Not likely to crop very far north; they are not very hardy and should be given warm sunny well drained sites never dank hollows. Walnuts also need to be in multiples to help pollination- the male catkins do not come out the same time as the bat-winged female flowers- though catkins can be kept dry and used to dust later opening females by hand. The value of walnut wood is relatively high and the nuts have a ready market around Christmas. Immature walnuts that can be easily pierced with a needle can be pickled. Walnuts are notoriously blackening to the skin when their nuts are extracted from the decaying husks. Once washed and dried walnuts do not keep as long as say hazels, though some have claimed they freeze well, if shelled use quickly as they may mould.

Sweet chestnuts are potentially even larger growing than walnuts though often making squatter bushier trees. To give a heavy crop of good nuts sweet chestnuts need two hot summers in a row and so are only ever likely to crop well in the south east. They will actually grow further north than walnuts but are far less valuable as timber as they often have very twisted grain. The nuts are traditionally roasted but can be used in many ways including a sweet conserve.

Beech nuts or mast is now considered unsafe as human food though an improved more edible selection is probably simple the sheer size of a beech tree makes these unlikely to become popular cropping plants. Likewise for the oak; acorns, once leached of their excess tannins or those selected for a sweeter nut could be a modern crop but really only on a farm scale. Sadly the North American Hickory and Pecan nut trees are similarly too big as well as too tender and needing a hotter summer than that of the UK, though with climate change they could have some future. The Pecan can grow extremely large and is less likely to be a crop here, however the Hickory might and it also may have value simply for the timber for smoking foods as this is thought by many to be the ‘tastiest’.

The size again mitigates against most tropical nuts being considered under cover- although coconuts can crop from only a few years old they are already thirty feet or more across! The cashew is relatively small and compact and in theory could be grown here under cover if sufficient warmth was available though it looks rather uneconomic.

There are a couple of other hardier nut trees with future cropping potential- the Monkey puzzle Araucaria, although being immensely slow growing, huge trees, and having male and female forms, has often produced it’s tasty edible nuts in the UK and a smaller more rapid bearing form would be immensely useful. Xanthocerus sorbifolia, is a decorative small tree, very rowan like, it has gorgeous (edible) flowers followed by lemon sized pods which split to eject black shelled seeds very similar to Macadamia nuts. This has huge potential because it’s already fairly compact and delightfully ornamental, I predict you’ll be seeing it before long.