Hazelnut Care & Pruning

Hazelnut grows naturally as a multi-stemmed bush, throwing new shoots from the root crown throughout its life. Formative pruning works with that habit rather than against it, selecting and keeping a small number of main stems - commonly three to five - and removing the rest. Suckers are not a nuisance to tidy up at leisure: left alone they crowd the stool, block light and air, and divide the water and nutrients that should be going to productive stems. Cut them at ground level, because a stub left 10-15 cm above the soil simply pushes out several new shoots in spring.

The second habit that governs everything is where the crop forms. In hazelnut the nuts come from buds at the tips of the previous year's shoots, so shortening those annual shoots removes next year's crop from that branch. Tipping the growth is the single most common pruning mistake, and it is committed most often by growers used to fruit trees, where heading cuts behave completely differently.

Timing follows from the plant's dormancy. The window runs from late November, once leaf fall is complete, through the peak month of January and into February, with the first ten to fifteen days of March as a last chance. After that, bud burst and the rise of spring sap close it. Do not prune below -5°C, when frozen wood turns brittle and the fibres tear instead of cutting; do not prune on wet or foggy days, when the open wound is an invitation to fungal spores; and do not prune in summer, when the bush is in active growth.

In a young planting the work is structural. Saplings go into holes prepared the previous autumn, typically 50x50x50 cm, with spacing of 5-6 m between rows and 3-4 m within them; planting finishes by mid-March so the roots establish before shoots start. Two or three compatible varieties in the orchard improve pollination, and support stakes are worth the trouble on exposed sites. This is also the period of highest disease risk: bacterial blight is at its most destructive between one and eight years of age, when a canker can girdle a young trunk and kill the plant outright.

In a productive orchard the annual routine settles down: remove dead, broken and diseased wood first, thin branches that cross, rub or close off the centre, take out suckers, and seal cuts thicker than about 2 cm. The restraint that matters most is volume - never remove more than about 30% of the canopy of one bush in a single season. A bush stripped back hard responds with a mass of vigorous, unproductive vegetative growth and loses more than it gains.

Ageing orchards need rejuvenation rather than maintenance, and it is best done gradually. Replacing worn-out stems with strong young ones over several seasons keeps the bush cropping while the new framework builds, whereas a single drastic cut sacrifices years of yield. In every age class the same two rules apply: cut back to the branch collar without damaging it and without leaving a stub, and take the prunings out of the orchard rather than stacking them at the edge.

Every benefit of pruning is also a disease measure. Air circulation through an open canopy shortens the time leaves stay wet, which is directly a reduction in fungal disease pressure - the powdery mildew guide names a crowded canopy as a factor that increases disease severity. Light reaching the lower branches evens up ripening. Spray penetrates to the inside of the bush instead of coating the outer shell. Harvest goes faster. None of that shows up as a single line in the accounts, but all of it does.

Hygiene during pruning matters as much as the cuts themselves. Disinfect shears and saws between bushes, and treat that as compulsory after working on a bush showing canker or bacterial blight symptoms. Cut cankered wood well below the visible margin, and destroy the material rather than leaving it in the orchard, where it becomes an overwintering site. See hazelnut diseases for the specifics on how far below an infection to cut.

The relationship runs the other way too. Heavy pruning combined with heavy nitrogen produces exactly the soft, watery growth that frost and infection exploit, so the pruning plan and the fertilization plan need to be made together rather than by different logic. Balance, not maximum vigour, is what a productive hazelnut bush is being managed towards.

Harvest preparation starts at least a couple of weeks before the first nuts come off. Mow or strim the ground cover under the bushes, clear stones, fallen branches and leaf debris, level anywhere water pools, and open up the orchard tracks. Seasonal labour should be arranged a month ahead, and the thresher, drying area and sacks checked before you need them. Ripeness is judged from the crop itself: the green husks begin to brown, the husk tips curl and open, the nuts loosen and drop at a touch, and the first nuts start falling naturally.

After picking, speed decides quality. Threshing should follow within 24-48 hours; leave it longer and the husk sticks to the shell and quality drops. Drying takes three to five days in good sun, and nuts go into storage below 6% moisture - damp nuts mould. Store in jute or other breathable sacks, never plastic, on pallets and about 10 cm clear of the walls, in a cool, dry, ventilated space, and check periodically for moisture and mould.

Post-harvest is also the start of the next season rather than the end of this one. Late August to early September is when the first protective copper application goes on, before the autumn rains begin; September-October is the best window for soil sampling; shallow cultivation under the bushes exposes overwintering weevil pupae; and pruning can begin from November. Frost planning belongs in this stretch too - identifying the hollows where cold air pools and checking equipment long before you need it, as set out in the frost protection guide.