As you may have noticed in my previous articles I am obsessed by the need to develop more edible wild plants into garden worthy esculents. Just as we created the modern strawberry, cabbage, apple, sweet pepper, carrot, parsnip and so on. Most of our fruits and vegetables are quite distinctly different from their wild ancestors. They are larger, sweeter and less fibrous and although cultivation helps it is selection and hybridization that have worked the improvement. And it does not take long- The Student a superb strain of parsnips was bred from the wild stock in only a few generations by James Buckman, a Victorian who had similar ideas and wished to show how quick we could improve or en-noble wild plants.
In the search for new comestibles there’s one area that has not been greatly exploited on a garden or field scale and that is the nuts. Fruits are already aplenty, seeds, roots and tubers also, but we eat relatively few sorts of nuts and grow even less. Yet nuts are truly remarkable crops with enormous potential, and being perennial offer greener possibilities.
Nuts are seeds- thus they contain a far wider and richer store of nutrients and minerals than fruity pulps or carbohydrate stuffed roots. And furthermore as these seeds intend to generate a big woody plant those seeds we know as nuts are those larger ones with huge stores of oil. Indeed nuts can add enormous numbers of calories to your diet and if pressed give very good culinary and salad oils. There are also few foods richer in protein, the expensive part of food which is harder to get from most other plant sources. You can survive a long time with water and a pocketful of nuts. But nuts are a treat, and can be smoked or given extra zest baked with paprika, chilli pepper and salt, or even honey.
Nuts also store well, at least till the following year if they are well dried, in their shells, then packed in dry salt or sand in wooden boxes kept in a cool dark place. (Shelled nuts do not last as well.) I’ve eaten hazelnuts several years old and though not awfully good they were still edible. This is because nuts are seeds so they keep well; at least as long as they remain viable. Once they get old or are warm too long they may go rancid which is not nice nor palatable, indeed risky, and mouldy nuts are dangerous. However generally nuts are safe to eat for most of us though some people are allergic to some nuts. Thus always be cautious when trying new sorts.
Nuts can also upset anyone who eats them without moderation. I got terrible gip one night after playing cribbage with friends whilst consuming walnuts. The long evening resulted in too many nuts being eaten and extreme discomfort. Small children in the past were apparently occasionally killed by not sufficiently chewing a glut of nuts with the indigestible pieces blocking up in their guts. However do not fear; nuts are as safe as most foods; people have died from excessive apple pips and carrot juice.
Growing nuts offer other advantages- they are mostly far less demanding than fruit trees, both in soil fertility and maintenance. The hazel family will give valuable crops on stony hillsides where little other than goats would produce much. Nut woodland gives food as well as amenity or other value, and in a durable more lasting form than fruit- conveniently vendable for Christmas. Nuts are also relatively high value yet easy to package- good by the garden gate. Some, the hazels and sweet chestnuts, can be pollarded or coppiced to give timber in exchange for a year or two’s lost crop. This also allows them to be seriously reduced in size. As they are trees or big shrubs the area underneath can be used for shade tolerant crops such as blackcurrants and raspberries or for chickens or ducks, or compost heaps and leaf mould bins. But make sure the dropping nuts will be findable- or arrange sheets to catch them. Although chickens won’t touch them squirrels and wood pigeons will rob your nuts voraciously. It helps to have bare soil deep in leaves or mulch under the trees as then you can rake through and find the nuts the squirrels have just buried. I dream of getting them to post nuts through a knothole in a box- allegedly a house once collapsed from nuts filling the attic….
Now apart from the squirrels the only drawback of most nuts is they get too big- as mentioned some can be coppiced or pollarded easily. Even so most nuts are not dwarf enough for small gardens and not happy in containers thus making them only suitable for those with bigger gardens. Not only do we need more nut variety but dwarfing rootstocks as well. I am yet to see the root restraining bags offered to work over decades at restraining the bigger trees but these offer some possibility in the shorter run and for the shrubbier ones. Hazels and almonds are the best options and some relatively dwarfing varieties are becoming available.
But if you have space a walnut grove could be a rewarding long term low cost investment- especially as they do well from nuts sown in situ. A few named varieties exist- I have a Franquette but the majority you see are seedlings. A group crop better than single trees as the male and female flowers rarely bloom on the same tree at the same time. You can collect up early male catkins and keep them dry to dust over later female flowers. There are many walnut relatives, most with less enjoyable nuts, but these rarely crop well in the UK. With climate warming these and our own, or rather Persian, walnut may be cropped further north than at present- but as they can take decades to crop it will be a problem to find out. Sweet chestnuts are another dubious beneficiary- they might grow further north- but if the greyer damper summers we currently experience continue they may not crop well. Sweet chestnuts need two good summers and autumns in a row to crop well. Certainly mine here in Norfolk does not often give good crops- but it sure grows well. But the walnut crops far better and more regularly. And both are huge trees.
Almonds are much more compact, they can even be grown in big containers but resent it. As a small tree they are the best choice for many and the tastiest, though they’re hard nuts to crack and short lived trees. Pretty in flower their major drawback is peach leaf curl which means they have to be kept covered from midwinter till summer or sprayed with such as Bordeaux at bud break. But given that then they do crop readily in Southern and Eastern England and with some shelter or cover almost anywhere. Ruthless thinning may be needed with a good set though. Sweet Almonds must not be planted near bitter almonds, peaches, nectarines or the ornamental forms as they apparently become bitter if so pollinated.
Hazels and their improved forms Cobs and Filberts, are the quickest to crop, hardiest and by far the most useful nuts. However most varieties do make quite substantial shrubby copses on their own- they proliferate side stems unless methodically pruned every so often and become thickets. And unless pruned they soon reach twenty feet or more high. There are hard to find dwarfing forms which can be cropping from knee high and stay only head height after a decade, I have one which is eight feet high and wide at twenty five years. More widely offered is the Red Skinned filbert which has a small sweet nut on a relatively compact tree and a good choice but needs another to help pollinate it. Indeed all nuts do better in groups as most are wind pollinated. The Webb’s and Prize Cobs are good croppers and big nuts much larger than the wild hazels but rather large growing. Seedling hazels from the wild can be grown and crop within ten years but rarely give larger nuts though have a good flavour. Shelling them is tedious though, it takes a lot to make hazelnut macaroons but they’re worth it. If you do crack a lot of hazelnuts save their woody shells which can be used to smoke foods most deliciously.
Talking of gourmet delights it is possible to buy hazel varieties with truffle fungus inoculated on their roots with the obvious intention- however mine have been in twenty years and not one truffle yet got but I live in hope. They’d do better on oaks- but acorns are barely edible and the trees huge, Likewise beech- the mast was once eaten but is now regarded as toxic.
And that is about it. Sure there are plenty of nuts from warmer climes- Macadamia, Brazil, coconut but none within fifty feet of being compact enough to grow under frost free cover. And with others, especially the North American nuts, it is usually not cold tolerance but their need for summer heat that stops us cropping them. Pecans and hickories suffer the same way as sweet chestnuts. Pistachios likewise are used to very cold winters but hot summers. For all these our drab summers stop them cropping.
There is one unknown nut that shows some promise though. Xanthoceras sorbifolium. From China this was introduced in 1866 as an ornamental. Originally the flowers, leaves and fruits were all eaten so it has great potential. A small tree looking very much like a mountain ash but with horse chestnut even orchid like blooms then it produces big green capsules containing handfuls of round black nuts. These seem ok raw better cooked, though in these litigious times I can’t suggest you try them for yourself. Pretty tree though, lovely in flower, just needs improvement.