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Picking

Hazelnuts ripen during September. The actual time of ripening varies from year to year and depends on late-summer warmth. Expect the first hazelnuts to fall around early- to mid-September. A word of warning though! The first nuts to fall are often empty, so it is worthwhile waiting a week or so before making your collection. Where they are accessible, it is better to collect directly from the tree and leave the ones on the ground for the mice.

The ideal time to collect is when the nut is easy to remove from the husk. This indicates that they are just about ready to fall. Carefully pull the clusters of nuts from the branches and keep in buckets or breathable bags.

Extraction and storage

Perhaps the simplest way to extract hazelnuts is to pick them individually out of their husks. This can be time-consuming if you have a large number, but allows a very simple test to be performed. This test separates those hazelnuts that will grow from those that may not.

The nuts (without their husks) are thrown into a bucket of water. Those that sink will more than likely grow, those that float won’t (or will produce a much smaller seedling). Simply discard the ‘floaters’, somewhere where the mice can clean up, and keep the ‘sinkers’.

Pretreatment

Mix the ‘sinkers’ with an equal amount of horticultural sand (one handful of sand to one handful of seeds). Find a pot large enough for this mixture and a bit more. Place a few stones in the bottom of the pot for drainage and cover these with sand. Add the seed/sand mixture and cover with a few centimetres of sand. Label the pot and place somewhere shady.

Hazelnuts are a great food for mice. Wherever you put them, mice will find them! You will need to cover your pots with some wire mesh with a small enough mesh size that mice can’t get through. Leave the pots for the winter.

Sowing

When the seeds show signs of germination (check them from the end of February) it is time to sow them. In pots, simply place two seeds about 2-3cm deep, firm and water. Keep the pots moist.

In seedbeds, we can broadcast the seed. Aim for about 400 ‘sinkers’ in each square metre – you should get 200 plants. The seeds must be pressed into the soil either by rolling or by using a large flat board. Cover the bed with 2cm of horticultural grit.

Don’t forget those mice! They will still discover your hazelnuts and, before long, you’ll be left with nothing but a seedbed full of holes! Cover your beds with netting and your pots with wire mesh. When the plants are about 15cm tall you can remove the protection. Hazelnuts are also a favourite food of jays and pheasants.

Growing

Maintain protection from our wildlife during the growing season. Hazel doesn’t readily suffer from pests or diseases, so it should only be necessary to keep your pots or beds weed-free. Feed regularly and water during dry spells.

Hazel can reach 40cm in one year. However, you do not need to transplant them for a second year provided they have enough space. If they do not have 10cm of space around them, they should be transplanted. Re-pot your pots where necessary and keep well-fed during the second year.

Planting

Plant your hazel tree into its new home when it is two-years-old. Prepare the site well by clearing away any weeds or grass and make a hole big enough to accommodate the root ball. Plant carefully in the hole, to the same depth as it was in the pot or seedbed, and firm back the soil.

If you want to establish a hazel coppice area, let the plants grow for three or four years then cut them back to the ground. This will encourage the growth of strong, straight stems typical of coppiced hazel.

Picking

The cones can be collected from the trees from about October onwards. The later you leave it, the fewer seeds will be left in the cones as they begin to disperse. They do not have to be completely brown, but they should have already started to turn brown. Collect them into cotton or hessian bags preferably. If they are left in plastic bags they may heat up causing damage – they have a high moisture content.

Extraction and storage

The cones should be stored in a plastic, wooden or metal container – like a biscuit tin or bread basket lined with plastic sheeting. The container is placed somewhere warm.

As they dry, the cones will open and release their tiny seeds. We stack bread baskets on top of each other and the seeds fall through each layer to the bottom, lined basket. The seeds can be left like this all winter. To loosen the last of the seeds place the cones into a sealed bag and shake. This should release the remaining seeds.

Your extracted seeds can now be stored in plastic bags, sealed and labelled in a cool, dry place (the fridge is ideal – NOT the freezer).

Pretreatment

Four weeks prior to sowing, place your extracted seeds in a cotton bag and soak them in clean, cold water for 24-48 hours. The seeds should then be surface dried. This can be achieved by placing the full bag of seeds (tied tightly) in a spin drier and running this for a minute or so. Alternatively, an old pair of tights can be used, the bag of seed placed in the ‘foot’ and spun carefully around the head.

Mix the seeds with a little moist horticultural sand and place in loosely-tied plastic bags in the bottom of a fridge (not the freezer!). Four weeks at low temperatures for moist alder seed improves the speed and evenness of germination.

Sowing

Alder grows very fast provided plenty of moisture is available to them. Aim to sow during April on seedbeds or in a pot (around 5 seeds per pot and remove all but the strongest seedling).

Cover the seed thinly (3-5mm of coarse horticultural sand or grit). It is important that the seed is not covered too thickly as this could prevent germination. Firm the seeds gently.

Watering

Never let alder seeds or young seedlings dry out! These are trees that grow on damp ground and drying out can very quickly lead to the death of many plants. Stand pots in a shady, sheltered spot outside and water, from the top, until the seedlings emerge. Keep moist at all times.

Growing

Following pretreatment in the fridge, alder should germinate rapidly. Alder can produce its own nitrogen (the element essential for strong growth). Check this out when you dig up your seedlings in the winter. Look for the root “nodules” – small, orange lumps on the roots. This is the point where certain bacteria extract nitrogen from air pockets in the soil and make it available to the trees. Because of this, feeding alder in seedbeds is not so important, but they will benefit from a small application of fertilizer when they are about six weeks old.

It would not be unreasonable to expect up to 60cm growth in the first year, but the plants can be transplanted or left in the pots (repotting if necessary) for another year. Plants in pots will need to be fed regularly whilst they are actively growing (April-September).

Planting

When your alder is tall enough, it can be planted into its new home. Prepare the site well by clearing away any weeds or grass and make a hole big enough to accommodate the root ball. Plant carefully in the hole, to the same depth as it was in the pot, and firm back the soil.