Cobnuts or hazelnuts are not very large nuts, but they are sweet, tasty and easy to crack. The trees are easy to grow and have the advantage of producing catkins or tassels of male flowers from midwinter to early spring. The female flowers are inconspicuous red tufts. Fortunately, both types are wind pollinated, which compensates for the lack of pollinating inserts so early in the year. There are several self-fertile varieties, so it is not necessary to grow more than one if you are short on space. They are perfect for providing shade in which to sit plants as well as to grow shade-loving plants. They are really a large bush, rather than a tree, growing to no more than about 4m/13ft high, which makes them suitable for a small garden, unlike many of the other nut trees.
The main visual difference between cobnuts and filberts is that the husk surrounding the shell does not completely cover the cobnut – you can still see the tip of the nut – whereas on the filbert the husk completely encloses it. The trees produce better crops if they are pruned and maintained, but they can be planted in a wilder part of the garden and left to their own devices if you prefer.
Unlike most fruit, cobnuts like a partially shaded spot that is sheltered from strong winds. The soil should be free draining but moisture retentive, and it should not be too rich. Plant the young bushes in autumn or early winter at distances of about 4.5m/ 15ft. Mulch with manure to help retain moisture around the roots.
Pruning and training
Both can be grown in two ways. They are either grown as a tree with a short “trunk” about 45cm/l 8in high with up to a dozen branches or as a stool, in which all the main stems come directly from the ground, more in the manner of a bush. Whichever way you choose, train the plants to be open-centred. Heavier crops can be obtained by “brutting” which opens up the bush so more female flowers can form. This involves the curious practice of part-breaking some of the outer side shoots and letting them hang down.
Harvesting and storage
Pick the fruit as the husks are beginning to turn yellow. The nuts are borne after three to four years. They can be eaten fresh or died and then stored until you need them
Pests and diseases
These plants have few problems with the exception of squirrels that steal the nuts.