Pruning and training
Pruning new plants
Cobnuts and filberts grow on their own roots so you do not need to worry about rootstock selection. They are usually bought in as one year old whips which are straight up and down with no branches.
- Prune the leader to the height of 45cm (18in) in the winter after it has been planted
- The following summer it will produce laterals (sideshoots). Remove any shoots growing low down on the main stem and any other laterals that are badly placed. Well-placed laterals should be shortened by a third
- The following winter, remove any excessively strong, upright growth. To create a well-balanced framework, tip prune the sideshoots
- The shape you are aiming for should be open centred with no more than eight to ten leaders growing upwards and outwards
- Stop (remove the tip of) the main laterals when they reach a height of 1.8-2.1m (6-7ft), cutting them back to a bud or weak lateral. This will encourage sideshoots which will bear the catkins and flowers
Pruning established plants
Summer pruning: In August you can use a technique called "brutting" to get established bushes to crop more heavily. By hand, break the longer side-shoots of this season's growth by bending in half but leave the broken section hanging on. This opens up the bush and lets in the light to encourage more female flowers to form on the weaker growth. It also reduces vigour.
Winter pruning: Winter pruning is undertaken to remedy congested growth. The ideal time to winter prune cobnuts and filberts is when the catkins are releasing their pollen. The disturbance will release more pollen and increase the rate of pollination.
- Shorten the brutted branches from the summer to three or four buds
- Leave the short twiggy weak growth alone as this mainly carries the female flowers
- On mature bushes remove up to a third of old or overcrowded shoots. Cut them right back leaving only a 2.5cm (1in) stub; new branches will re-grow from this point
- Keep the centre open and free of inward-growing shoots
- Remove any suckers from the base of the tree
Harvesting and storage
Cobnuts and filberts should start to produce nuts after three or four years. They should be harvested when the husks begin to turn yellow around late September.
Store the nuts in a dry, airy room or shed in slatted boxes in shallow layers or in net bags hung up. They need to be turned regularly to ensure they are drying evenly. Once they are dry remove the husks and store as before.
If squirrels are a problem, you may need to harvest your crop before they have ripened; however, they will not develop such a good flavour.