Never tried growing these prolific plants before? You'd be nuts not to give them a go! Anthony Bennett explains the best way to cultivate filberts, almonds and walnuts
Our plots turn out a rich variety of fruits and vegetables, but how many of us grow a crop of nuts? There are a number of nut-bearing trees well-suited to the British climate and yet they’re too often overlooked as a source of food. This is a shame, as many produce delicious crops, look decorative and attract wildlife, helping to increase the number of pest predators on your plot.
Hazels, which include cobnuts and the closely related filberts, are the most popular of these trees. They do not get too large and offer a stunning display of catkins. Other types may prove a little more of a challenge, but if you have the space and patience they are well worth growing. These include the almond, a relative of the peach, which may be trained against a south-facing wall to produce an occasional crop of sweet nuts. Choose a late-flowering cultivar to avoid frost damage to the delicate blossom. Sweet chestnuts are real beauties and can be grown with great success in the southern half of Britain. A careful selection of varieties will see you roasting the mahoganycoloured nuts on an open fire within four years of planting. Grafted walnuts complete the line up for an autumn harvest.
It doesn’t matter what soil type you have: there’s a nut for it! Hazels are perfect for smaller plots and cope with most conditions, so long as they are well-drained. They can be grown in a sunny spot or somewhere that is partially shaded. The trees will not require any shelter in all but the most severely exposed sites as they are wind pollinated and do not rely on visiting insects to perform the task. There is no need to add lots of organic matter to the soil as nutrient-poor conditions will encourage them to flower and fruit.
Walnuts also like a free-draining soil, but one that retains moisture. Good, deep loam-based types are best, but just about any moist area that is also free from winter waterlogging will be suitable. If the ground dries out completely in hot summers there is a risk that the nuts will drop before they are ripe – opt for another tree if this applies to you. Walnuts will need a relatively sheltered site that doesn’t sit in a frost pocket. Late, hard frosts will seriously knock back emerging foliage and flowers making a good crop unlikely. Sweet chestnuts are only suitable for plots with an acidic soil. Once established they will spread to become large trees, so ensure you have adequade space for them. Pick a light, well-drained piece of ground in a position that isn’t prone to late frosts – sandier areas are well-suited to chestnuts.
If you have a sunny, south-facing wall and can prepare your soil by digging in plenty of organic matter consider an almond. It is best grown in a wall-trained fan, much like peaches and nectarines, so that it can soak up the sun’s rays and increase the chances of successful nut formation. Pick a late-flowering variety such as ‘Mandaline’ – its blossom appears at the end of April.
The best time to plant any tree is during autumn, when bare-root specimens may be bought from the nursery ready to go. Do this in November and the root system can settle in well before the growing season gets underway in spring. At this time of year, the soil will still be warm from the summer, helping roots to find their feet before the cold descends. If you want to get started right now, however, don’t worry too much, as trees may be planted at any time during their dormant period, from mid-October right through until February, so long as the ground is workable and isn’t frozen or wet.
Most trees are planted in much the same way. Dig out a hole with your spade that’s at least one-and-a-half times the width and depth of the root system. Set the tree at the same level it was buried to before – look for a change of colour on the stem, which will reveal the original soil depth. Fill back a little of the earth then spread out the roots evenly along the bottom of the hole. Continue adding soil, pressing in firmly as you go to get rid of any air pockets. Walnuts and chestnuts will benefit from the support of a tree stake for the first few years of their development and this should be knocked into position at planting time. Tie the trunk to the stake at a couple of intervals using rubber tree ties – loosen them as the plant grows.
Almonds should be planted so that the central stem emerges about 25cm from the wall allowing the plant to soak up the rain. Incline the tree towards the wall using horizontal wires stretched at 30cm intervals to support the branch framework. Look for plants grafted onto a dwarfing rootstock such as ‘St Julian A’.
Once your trees are in the ground they need little encouragement settling in. If the weather is at all dry, water heavily during the first spring and summer after planting. This is particularly important for thirsty nuts such as sweet chestnut and walnut. It is better to water generously less often than to simply wet the surface at regular intervals and encourage shallow rooting.
Keep the base of trees weed-free to help them establish. Most will benefit from a clear area of at least 1m radius beneath them so that there is no competition for moisture. Hazels grown as a standalone tree within a lawn should have the grass surrounding them mown short, which will also make collecting the nuts considerably easier in autumn. Other trees may be mulched in the spring to a depth of around 5cm to suppress weeds. Keep organic matter from touching the trunk as it could lead to rotting.
To increase your chances of achieving a harvest of nuts from almonds, you will need to give them extra attention, particularly during spring when late frosts can batter the blossom. If the temperature looks set to drop to near freezing, cover wall-trained trees with a layer of horticultural fleece to keep flowers intact. Later blossoming varieties stand the best chance of success but in cold springs you may need to help pollination along by gently teasing a cotton-wool bud into the centre of each flower, mimicking a bee.
Given enough hand watering, there isn’t too much to do when it comes to looking after your runner bean plants. But you should be on the lookout for any seasonal pests or diseases. In the early stages of growth, stay vigilant for signs of bean seed fly – their tiny white grubs eat into seeds and young stems, and can cause seedlings to fail. Traditionally, the best way to deal with an infestation was to dust the drills with derris powder – but what was once considered a natural pesticide (it’s derived from plant extracts) has been found to be toxic and a ban is imminent. Instead, use a fleece covering to protect young plants (this will also boost growth by warming the seedlings), switching to better-ventilated mesh as summer wears on, to ensure they stay protected but don’t overheat.
Of course, planting to attract predatory insects – such as yarrows for ladybirds – will help fight off unwanted visitors. Slugs and snails may also attack young shoots – keep an eye out for holes and tell-tale slime trails, especially first thing in the morning (these critters are most active at night). There are plenty of organic ways to deter slugs and snails – try surrounding the plant with a continuous circle of crushed eggshells, or adding grit to your mulch – as they won’t fancy slithering over either of those sharp surfaces.
There are several diseases to look out for – foot rot, bean rust and mildew are among the most common. An otherwise healthy plant should grow out of the latter if you keep it well mulched and watered, but remove any badlyaffected areas. Bean rust, identified by white spots that later turn rusty brown, is a fungal disease. It usually occurs too late in the season to do any significant damage, but you should remove any plants that have been struck down to minimise the risk of it spreading. You can spot foot rot by checking the stem bases – if they’ve gone black and begun to rot, your plant is probably being attacked by this fungal infection. There’s no remedy, so prevention is essential – making sure you’re rotating your crops effectively is a good first step.
It will be obvious when your nuts are ready for harvesting. Hazelnuts will turn brown and can be picked from the tree for eating fresh or storing. To do the latter, place the nuts into a tray and leave them in a warm place for up to a week before putting them in airtight containers. Some sweet chestnuts, such as ‘Marigoule’, will be ready to enjoy from late September and in as little as four years from planting.
Walnuts may be harvested early, in late June, for pickling, but you’ll have to wait until October if you want to savour them the traditional way. Remove the husk from the shell, wearing gloves if you are concerned about staining your fingers. Clean off the nuts and then dry them off in a warm place. Almonds form a soft, outer flesh, which must be removed at the end of summer to reveal the nuts.
Most nuts require only minimal pruning to keep them healthy. Hazel bushes may be bulked out by autumn pruning in the first four to five years. Cut back that season’s growth by half, making a cut to an outward-facing bud. Once the bush begins flowering, switch your pruning regime to the spring, cutting back previously fruited branches to just a few buds which will encourage new growth. A late summer pruning should then remove any crossing branches or those at the centre of the bush to keep it open.
Suckers – shoots growing away from the main plant – should be snipped back to where they emerge. Walnuts are pruned in autumn when there is less risk of causing the tree to bleed its sap. Keep pruning to a minimum, removing crossing or poorly positioned branches. The same timing applies to sweet chestnuts. In both cases, aim to develop a clear trunk up to head height, allowing branches to grow out above this point.
Almonds may be pruned once the fruits have set – around July. Cut away crossing branches and any shoots growing into or away from the wall. Tie new shoots to the horizontal wire supports so they develop a fan arrangement.
Only plant trees when the ground is not frozen. Dig out holes that are generous in size and that give the roots plenty of space to spread out.
The last chance for planting bare-root trees before they launch into growth. Knock tree stakes into place for walnuts and sweet chestnuts.
Apply a springtime mulch of organic matter around the base of trees. This will lock in the moisture while keeping weeds at bay.
Prune almonds to remove stray shoots and any overlapping branches. Finish harvesting walnuts for pickling early in the month.
Cut out badly placed branches from hazelnut bushes. Prune the branches clogging up the centre of the bush to keep it open.
Begin harvesting and enjoying nuts, including early-ripening varieties of sweet chestnut and hazelnut. Dry off any you want to store.
Unfortunately, we’re not the only ones to enjoy nuts – the common grey squirrel loves nothing better than pilfering your hard-earned crop, so some form of defence is needed. With more than 2.5 million grey squirrels in England and Wales (versus just 15,000 reds), this isn’t a small problem. Some over-protective gardeners resort to setting traps for the crafty tree dwellers, but then they are left with the unenviable task of dispatching the poor beasts. Grey squirrels are non-native animals and are classed as vermin, which means if you set out to catch one you are legally obliged to kill it.
A far more humane option is to prevent squirrels reaching your trees in the first place. For this you require a sturdy fruit cage with tough, wire netting that isn’t easily gnawed. The nets will need to be buried into the ground at least 15cm deep and then regularly checked for any gaps, which a persistent squirrel will quickly breach.
Alternatively, for larger trees such as walnuts, consider adding baffles (curved or angled obstructive devices) to the trunks of the trees to physically prevent the squirrels climbing up. These should be set at shoulder height and need to be at least a metre wide. Position new plants out of jumping distance from surrounding trees so squirrels can’t drop in for a free meal. Prolific nut-bearers, such as the hazels, should give a big enough haul to satisfy both human and squirrel connoisseurs.
Related Forum Topics
Nuts: Varieties To Try
A new variety from France that should make almond growing a lot easier. It is self-fertile and well-suited to the British climate.
Pink-white blossom leads to a pleasing crop of nuts. This variety is self-fertile and is resistant to peach leaf curl, which can sometimes infect almonds..
This vigorous American variety of cobnut is grown commercially as it achieves bumper yields of good-sized nuts. It is self-fertile and quick to establish
Cobnut Red Zellernuss
With its red-tinged leaves and husks, ‘Red Zellernuss’ is a very pretty choice. It is fast growing and consistently produces a heavy crop.
Filbert Halle Giant
A vigorous, upright bush that will yield a good-sized harvest. The sweet tasting filberts can be stored for the traditional winter nut bowl.
FIlbert Kentish Cob
The most popular of all the cobnut and filberts, thanks to its heavy crops of large, long,– light-brown nuts which have a good flavour.
Sweet Chestnut Marigoule
This reliable chestnut produces a crop early in the season. It can be grown on its own and forms deep-brown nuts.
Sweet Chestnut Marron De Lyon
A self-fertile French variety of chestnut that begins yielding its nuts as early as three years after planting, so you won’t have long to wait.
The most popular variety of walnut thanks to its combination of hardiness, speed to cropping and relatively compact size. It will form a decent, wellflavoured yield of elongated nuts.
Pick this variety if you have a small plot. It bears plenty of nuts four years from planting and reaches just 6m tall. It's self-fertile so you can successfully grow a single tree without a pollinating partner.
It’s great when a plant is ornamental as well as productive. Nut trees have decorative value by the spadeful. Many are worth growing as specimens within a lawn where they can show off their splendour.
Hazel trees are known for their beautiful pale-yellow springtime catkins, which dangle from the branches like little streaks of gold. The prized nuts look attractive too, with their frilly husk surrounds, and there’s even a red-hued variety for extra appeal – look out for the ‘Red Filbert’.
Many nut trees, such as the sweet chestnut, can also be expected to put on a bright autumn display as their leaves join other trees to produce fiery colours before they fall. If you’re after a spectacular floral display, you can’t do much better than a wall-trained almond. The branches are covered in a spray of pale pink, dark-centred flowers in spring which look just as stunning as any of the other flowering shrubs.