Hazel is a hardy nut bearing tree where;
Corylus avellana is the native Hazel or Cobnut and, Corylus maxima is the Filbert.
The trunk of the tree is often contorted and often produces many shoots (suckers) from its base.
The grower can either allow these shoots to develop and form a shrub or remove them to form a standard tree.
If allowed to grow avellana can grow to 6metres (20ft) high with a similar spread, and maxima to around 3 metres (10ft) high with and spread.
Apart from being a source of nuts, they are also quite attractive trees producing catkins (male) and inconspicuous flowers (female) in spring.
Catkins are formed in late summer/early autumn but do not mature until January / February the following year.
Inconspicuous dark-red flowers appear at the same time that the catkins are opening and lengthening.
The hazelnut forms from the ovary of these flowers.
The flowers are wind pollinated and this takes place just prior to the leaves opening.
In some seasons this process and ultimately the quality of the crop can be affected by the timing of the leaf burst.
For example; In cold winters the leaf burst is generally quite late thus allowing pollination to take place before the leaves open.
In mild winters the leaf burst can be earlier and the open leaves hinder the pollinating process, resulting in a poor crop.
In terms of wildlife, hazels are often hosts to a multitude of insect life for example, ladybirds are attracted to aphids that dwell in the leaves.
Then there are the insects such as; butterflies, damselflies and dragonflies that are attracted to this plant either for food, shelter or prey, these in turn attract birds.
This can be done by either sowing seed or layering.
Collect and sow a few nuts as soon as they are ripe into pots of seed compost and place in a coldframe to germinate.
Alternatively, sow a few into a pre-prepared nursery bed .
Mice may be attracted to seeds sown in the nursery bed so delay this method of sowing until spring.
Once germinated pot on into individual pots of potting compost and grow on in a coldframe for another year before planting out.
Form a shallow slit trench under a low growing two year year old stem.
Peg about 300mm (12") of the stem down with pieces of bent wire into the slit trench, refill the trench and lightly tread on it with the sole of your foot.
If the stem wants to spring out of the trench cut the underside of it and break / fracture it (do not completely sever it) this should reduce the springiness.
Once rooted (this usually takes around one year) you may find that the stem has rooted at each leaf node along the length of the layer.
These can be cut into individual rooted sections and potted on into individual pots and placed in a cold frame to grow on for another year before planting out in their final quarters.
Plant out in a sunny spot,in fertile, free-draining, neutral soil.
Idealy select an area that is protected from easterly winds to reduce the risk of bud damage in spring.
Established Hazels do not require pruning as such, it is better to coppice them, however in the first year after planting it is advisable to;
a) Reduce each main stem to the single best leading shoot and remove any side branches that are greater than half the diameter of the main stem.
b) Remove crossing dead or damaged branches.
c) Remove any inward growing side branches.
It may take up to five years to get large harvests!
Prior to this it may be a battle with you and the squirrels and mice as to who gets the few nuts that have formed.
The nuts are ready for harvesting when the husks start turning brown, usually from September onwards.(the squirrels/mice tend to pick them sooner)
Store the nuts in a cool dark place.
Pests and Diseases:
The nuts may be attacked by Hazelnut Weevils.
The hazelnut weevil is a beetle with a long snout or proboscis which has positively elephantine proportions in the female.
She uses it to drill a hole into the young nut as soon as it is set and the shell is still soft.
A single egg is laid in the developing kernel, and the hole heals over so there is no sign of infestation.
The egg hatches into a grub which feasts on the kernel until the nut falls.
The evidence of an attack is a hole in the nut shell where the young weevil emerged.
This is when a fruit is formed wthout fertilisation by pollen and has no seed.
A symptom of this problem is that the nuts remain on the branches all winter.