GROW YOUR OWN BOWL OF NUTS

If you’re going to plant a tree for Christmas, says Monty Don, why not make it a walnut, hazelnut or sweet chestnut

Nuts are delicious, healthy and can make wonderful garden trees, so I’m a big fan. However, the choice in terms of growing your own is fairly limited. If pistachios, brazil nuts, cashews or peanuts are your thing, you’re going to struggle. But walnuts, sweet chestnuts and hazelnuts all grow well in the UK, and Christmas is not complete for me without a big bowl of walnuts to dip into and a session roasting chestnuts on the fire.

But although I love walnuts and eat them most days, I do not have a walnut tree in my garden. I regret not planting one 20 years ago when there was space but I have nowhere to put one now – it is a large tree and also you should never plant walnuts, and in particular Juglans nigra, in an orchard or near apples or pears, and I have such trees. This is because the roots give off a toxin called juglone that other trees, and apples in particular, are sensitive to – it restricts their growth and can even kill them. This evolutionary ploy has allowed the walnut to grow without competition from neighbouring trees, so they should either be planted alone or in groups together. Although the juglone is also found in the fruit and leaves, it is not harmful to humans and can be safely composted.

Before anyone writes in, walnuts are not strictly speaking nuts but drupes. True nuts, such as hazelnuts, chestnuts, acorns and beechnuts, have a dry shell whereas drupes – including walnuts and almonds – are contained within a fleshy fruit. But these are botanical niceties; we know what we mean.

Two kinds of walnut are readily grown in this country, Juglans regia, the English walnut, and J. nigra, the American species. The latter grows faster but does best in the warmer, drier south of our country and is usually much happier in alkaline soil than acidic conditions.

I do grow hazels, lots of them (73 trees at the last count). They cross-pollinate easily between different versions of themselves and as a result there are numerous hybrids. The wild hazel or ‘cob’ – Corylus avellana – has rather rounded nuts that grow in clusters of two or four. The filbert, Corylus maxima, has longer nuts that are completely enveloped by a husk. If you really

want to be confused, the famous Kentish cob is actually a filbert.

Hazel trees start to produce nuts after four years and are most productive on light, open, stony ground. My rich clay loam is great for growth but not ideal for the fruit, although this was a bumper year and we collected basketfuls. The most nuts are produced on new wood, so pruning should be based around retaining an open structure with plenty of new wood – at least 15cm long – each year. This means pruning the oldest growth every three or four years.

The sweet chestnut, Castanea sativa, was, like the walnut, introduced to Britain by the Romans. It grows best on well-drained acidic soil so you’re unlikely to see a healthy mature walnut and sweet chestnut in the same garden. It will thrive if rhododendrons or azaleas are nearby and, given the right soil, will live to an incredible age – some are more than 2,000 years old. They grew well at my boarding school and we’d eat the nuts raw in autumn – but they’re much nicer roasted on a fire and eaten hot in your fingers. n

Monty with his hazelnuts and (inset) filberts fresh from the tree