Cobnuts are one of the most rewarding crops a small orchard can offer. They need little in the way of pruning, tolerate a bit of shade, and crop reliably once established. The tricky part is not growing them — it is catching the nuts at the right moment and getting them dry enough to keep. Get that right, and you will be eating your own cobs well into the new year.

Knowing When the Crop Is Ripe

Cobnuts do not ripen all at once, and they certainly do not wait for you to be free at the weekend. Ripening begins in late August in most of the UK and can run through to mid-October, depending on variety and the summer we have had. Warm, sunny Augusts push things along; cool, wet ones slow them down.

The first sign is colour. The husks — that leafy green sleeve wrapped around each nut — shift from green to a yellowish, then brownish green, and begin to dry and split away from the shell. A ripe cobnut drops cleanly from the husk when you cup it in your hand. If you have to tug, it is not ready.

The most reliable indicator, though, is simply that the nuts start hitting the ground. Once that begins, you are in business — and you are also in a race.

Collect Little and Often

Fallen nuts need picking up promptly. A cobnut lying on damp grass overnight will take on moisture, and damp nuts are the ones that go mouldy in store. Squirrels, jays, mice and voles all know exactly when your crop is ready, and they will not wait for you to get round to it.

• Walk the trees daily during the falling period, ideally in the morning.
• Use a wide, shallow basket rather than a deep bag, so nuts are not crushed or sweated together.
• Shake the branches gently as you go — nuts that are ready will drop, and you save yourself several days of visits.
• Leave the husks behind where you can. They make decent compost and save you carrying extra weight.
• Keep an eye on the ground for nuts with a neat round hole in the shell, which means the nut weevil has beaten you to it.

It is worth noting that green, unripe cobnuts are a delicacy in their own right — picked in July, they can be pickled or eaten fresh with a little salt. But for storing, only fully ripe, brown-shelled nuts are any use.

Drying: The Step That Decides Everything

Fresh cobnuts contain a great deal of water, and if you store them while they are still damp, they will either go mouldy or turn rancid. Drying is not optional, and it takes longer than most people expect.

Spread the nuts in a single layer on shallow trays, slatted if you have them, and put them somewhere genuinely airy — a loft, a spare room, a shed with the door propped open, a garage with ventilation. The ideal is a dry, cool-to-mild spot with moving air. Full sun is not necessary and can dry the shells too fast while the kernels inside still hold moisture.

Turn the nuts every few days so that air reaches all sides. Depending on conditions, drying takes anywhere from two to six weeks. Speed it up with a fan if the weather is humid; do not be tempted to use a hot oven, which ruins the flavour and texture.

You will know they are ready when the kernels rattle inside the shells and the shells feel noticeably lighter. Crack one open — the kernel should be firm, plump and snap rather than bend. A good test is to weigh a sample at the start and again later; fully dried cobs lose roughly a fifth to a quarter of their weight.

Storing for the Months Ahead

Once dry, cobnuts keep well in a cool, airy place. The traditional method — mesh bags, hessian sacks or open trays in a cold shed or unheated room — still works beautifully. Aim for somewhere between about 5°C and 10°C, with good air movement and no damp.

• In-shell nuts store best, keeping their flavour for six to twelve months.
• Shelled kernels are far more perishable because of their high oil content. Use them within a few weeks, or freeze them.
• Avoid sealed plastic containers for in-shell nuts, which trap moisture and encourage mould. Paper, cloth and mesh are your friends.
• Check stored nuts monthly. Remove anything shrivelled, mouldy or light for its size.

A quick float test is useful before storing or using: drop the nuts into cold water. Sound, well-filled cobs sink; empty or weevil-damaged ones float. Dry the sinkers thoroughly before returning them to store.

Troubleshooting and Making the Most of the Crop

Mould is the usual culprit when stored nuts fail. It almost always traces back to collecting wet nuts, drying too briefly, or storing in a sealed container before the nuts were truly ready. If you find a patch of mould, throw out everything in contact with it — mould spreads.

Rancidity is the second problem, and it affects shelled kernels fastest. A stale, oily, slightly bitter taste means the oils have gone over. Freeze shelled kernels in small batches if you cannot use them quickly.

Small holes in the shell, often with a little powdery frass inside, mean the nut weevil got there first. There is no cure once the larvae are inside, but good hygiene helps: clear fallen nuts and husks promptly, and do not leave old nuts lying under the trees, where weevils overwinter.

Finally, give your trees something back. A mulch of well-rotted compost in spring, a light feed, and a little judicious thinning of congested branches will keep light and air moving through the canopy — which means better ripening, easier picking, and fewer disease problems next season. A small orchard of two or three well-chosen cobnut trees can easily produce more nuts than a family can eat, and they make a generous gift once dried and bagged.