When people first hear about the idea of Forest Gardening and replacing annual crops with perennials, one common question in response is: But where will the real bulk of food come from? How can we replace all those calories we get from the cereal fields without all the heavy work and energy input?
One of the answers is nuts. Nuts can be used in a similar way to cereals and perhaps the very best species of nut in terms of sheer yield in Southern England is The Sweet Chestnut.
We all know about roasting and boiling fresh chestnuts but they can also be dried and will keep for years this way. They can then be ground into flour to make bread and cakes. This was traditional in Southern Europe where they were sometimes known as 'Bread Trees'.
Chestnuts are also nutritionally similar to cereals but without the gluten and are full of Vitamin C.
Though not widely recognised as a viable crop in the UK, carefully selected varieties have been shown to perform consistently well in the warmer parts of the country and can give us up to 25kg per tree.
The good old Agroforestry Research Trust in South Devon planted a trials site for various species of nut trees in 1995 to discover the true potential of nuts as a staple food in the UK.
Their findings show that from a hectare planted with the most productive Chestnut cultivars we could expect 2.5 tonnes a year of green nuts a year, perhaps more. This compares with a typical yield of 4.3 tonnes per hectare of wheat grown organically in the UK. So the present yield may be lower, but when we consider the vast amounts of cereals and land that provide for lifestock, chestnut orchards may seem like a realistic alternative if were to move towards a less meat based diet.
And of course farming with trees requires less work, a lot less work!
Chestnut cultivars can start cropping after 3 years and will reach their full yield in10 years or so, but in that time they require barely any looking after.
Once they get going, all that is required is to come back every autumn and harvest the fallen nuts (*read bottom of page for squirrel issues). For the rest of the year, the orchard can be left in peace to serve as a permanent habitat for all kinds of other plants and creatures to enjoy - or be utilised to to grow further crops in a polyculture. In all that space that's left under the trees we can let poultry range, grow shade loving vegetables like Solomon's Seals, Wild Garlic, Sweet Cicely and also mushrooms (article coming soon!)
Compare that with all the heavy machinery and annual Ploughing > Feeding > Sowing > Weeding > Harvesting cycle needed to provide us with wheat alone and well, I know which I'd choose!
But is it really that simple - don't the trees require feeding? Nut trees do indeed require a decent supply of nitrogen to keep cropping well, but naturally, Nature has a solution...
Instead of all the trouble of carting around chemical fertilisers or manure every year, we simply plant nitrogen fixing plants to fertilise the ground for us, perennially. In the case of a nut orchard, we'd look for trees such as alders, sea buckthorns and eleagnus species which can also act as a wind break, and may provide us with additional crops themselves. Even more nitrogen could be supplied by keeping poultry under the trees, who'll happily drop little nitrogen bombshells all over the orchard free of charge.
I'm currently planting a small orchard of Chestnut trees in Devon, mainly seedlings. The seeds I've sown are those from the trials site in Dartington so the parent trees are all good croppers. Yes, seedlings are always unpredictable but there's a small chance that some of them could turn out to give decent crops themselves and I could then share these new varieties with others. If they turn out to be less fruitful then I can always top graft them with a proven cultivar, or coppice them for their durable wood.
If you're keen to grow nuts, you must go and see Martin Crawford's trials site near Dartington, Devon. He tends to give guided tours of the place every autumn, and there's also a weekend course for growing all kinds of nuts.
*Squirrels.... I love to see them around, but they're the biggest problem we face when growing nuts. Luckily the spiny casing on chestnuts will deter squirrels, but only for as long as they're on the tree - as soon as they hit the ground they're easier to get into and the squirrels will usually beat you to it! So if don't want to harm the squirrels, we must harvest the nuts off the tree. The only method I know is by banging the branches with a long pole regular and then collecting the fallen nuts - if you know of any others, please let me know!
I don't currently have any chestnut trees to offer - but do check the agroforestry research trust's catalogue.