Common hazel grows wild in the forests (Corylus avellana), from which comes several cultivars. It is a shrub, while the tree species is Turkish hazel (Corylus colurna), it is planted in parks or is used as a rootstock to derive the common hazel as a tree. Cultivated varieties are derived from common hazel and pontic hazel (Corylus pontica) and long-capped hazel, also known as Lambert's or Lombard's (Corylus tubulosa). We currently have many human-bred varieties. The varieties of hazel are divided into four groups: Lam-bertówki, Zellerówki, hybrids of Lambertines with Zellerkids and hybrids of Zellerkids with Lambertines with a predominance of the former.
Lambert Nuts are cylindrical in shape, surrounded by a tightly tubular casing, much longer than a walnut.
The Zeller group produces spherical or spherical-elongated nuts with a different cover, but not tubular. The fruit cover is characterized by deep indentations, and ripe nuts fall out of the casing more easily than in Lambertines.
Hybrids of Zeller's and Lamberk's show a clear advantage of Zeller's. During the period of maturation, the cover unwinds and the walnut comes off very easily. Three varieties are recommended for allotment and home gardens: Barcelona-Catalan, The giant from Halle and Gubeński.
Hazel is a shrub and is usually grown in a bushy form. However, studies have shown, that it bears fruit better, when it is run in the form of a tree, what is obtained, grafting noble varieties on Turkish hazel – by nature creating trees. Research on keeping non-grafted noble varieties of hazel in the form of a tree has shown, that if it was a typical form, so about one trunk, after being damaged by frost, it was very difficult to "bring it out"” back, that is, rebuild. So it's best to get out of the root collar 5-6 trunks, that is, to form an intermediate form between a typical tree and a shrub. This form allows the plant to be gradually rejuvenated, and in addition, it reduces the likelihood of damaging all trunks simultaneously. But who wants to have a hazel tree, he must select one or more twigs and remove side shoots from them up to the height, on which he wants to put the crown, e.g.. to the height 80 cm. Hazel cut in this way produces a lot of suckers from the root neck, which must be systematically removed.
The easiest way to propagate hazel is from seeds, although noble varieties, so that they do not lose their value, better to multiply by layering. Sow the nuts immediately after harvesting. Reproduction "by deposition” it consists in sprinkling the shoots with earth, in order to force them to form adventitious roots. We cut off the rooted shoots from the mother plant, thus obtaining seedlings. You can strong too, one-year-old shoots, grown from the mother plant, bend it to the ground and unfold it, by attaching to it with wire pins, and then cover them with a layer of thick earth 2-3 cm. As shoots, which struck, they lengthen, their base is covered with earth, until the height of the cover is 15-20 cm. In late autumn, the cover is opened and the twig and the rooted side shoots are cut off. Then it is cut into pieces like this, to separate rooted side shoots. Unrooted twigs are left for the next year for rooting.