Turkish Hazel: A Slim Street Tree, a Grafting Rootstock and Nuts on the Side

Stand under a Turkish hazel in autumn and listen to the bristly clusters of fruit cracking open, and you rarely guess what a quiet all-rounder is rustling above you. The Turkish hazel is not just a larger hazel bush but a species in its own right, with its own stature: an upright tree that outlasts decades, shrugs off the urban climate and has served nurseries for generations as the rootstock onto which cultivated hazels are grafted. And, almost incidentally, autumn brings down nuts that take some work but taste good.

A tree, not a bush

The most important difference first: the common hazel (Corylus avellana) grows as a multi-stemmed shrub, keeps pushing new shoots out of the ground and usually stays under five metres. The Turkish hazel, by contrast, forms a single, straight trunk with a dense, conical to egg-shaped crown. It reaches 15 to 20 metres, more in good spots, and can live for over 100 years.

Both belong to the birch family (Betulaceae), so they are close botanical relatives. In the garden, though, they behave completely differently. The Turkish hazel produces no root suckers, so it does not run wild and needs no constant thinning out of old shoots. Its bark is a signature in itself: pale grey, corky and, with age, deeply fissured lengthwise, almost like a coarse net.

The Turkish hazel originally comes from south-eastern Europe and, across its natural range, reaches as far as the Himalayas. That origin explains a lot: it is equally at home with hot, dry summers and cold winters. Exactly this range is what makes it so interesting for our gardens and towns.

The climate tree for town and front garden

Among specialists the Turkish hazel has for years topped the lists of future-proof urban trees, and for good reason. It tolerates what troubles most trees: baking paved surfaces, compacted soil, road salt in winter, exhaust fumes and weeks of drought. Its deep taproot keeps it stable and draws water from layers that shallow-rooted species can never reach.

For the home garden that means the Turkish hazel is a tree that copes even with a difficult spot, where a beech would long since be struggling. It casts only moderate shade, its foliage rots down well and its crown stays comparatively narrow, so it fits into a medium-sized front garden too.

The quiet worker: Turkish hazel as a grafting rootstock

Perhaps the most inconspicuous, yet most important, role of the Turkish hazel plays out underground. In the nursery it is used as the rootstock onto which cultivated hazelnut varieties are grafted. The reason is its habit: because the Turkish hazel produces no root suckers, you get a clean trunk with a crown instead of a sprawling bush.

That gives you a hazelnut as a standard or half-standard, one you can mow and harvest under, rather than a broad thicket. Such little trees are especially handy for small gardens, because the ground beneath stays usable. Anyone buying a grafted hazel should keep an eye on the graft union, though, and consistently remove wild shoots that break out of the rootstock below it.

Site and planting

The Turkish hazel is undemanding but appreciates a free-draining soil that never stands permanently wet. It likes a spot in sun to partial shade and gets by on at least four hours of sun a day. Waterlogging is the one thing it really dislikes, otherwise it grows on almost any garden soil.

The best planting time is autumn, roughly CW 40 to 46, as long as the ground is open and frost-free. Set bare-root trees during dormancy between autumn and early spring; containerised stock works year-round. Autumn has the advantage that the tree already forms fine roots by spring and then powers away.

1. Dig the hole generously

   Twice as wide as the root ball, the same depth. Loosen the base with a digging fork so the taproot finds its way down.

2. Set the stake

   For standards, drive a support stake in at an angle against the main wind direction before the tree goes into the hole, so you do not injure any roots.

3. Plant without going too deep

   The graft union or root flare stays above the soil. Fill in soil, press it down with your hands, do not tread it hard.

4. Watering ring and soaking

   Form a small earth wall as a watering ring and soak it thoroughly until the soil is fully moist.

5. Mulch

   A layer of leaves or bark mulch over the root zone holds moisture and protects the young tree.

Flowering, pollination and the nuts

Like all hazels, the Turkish hazel flowers early in the year, often as soon as February or March, long before the leaves appear. The male flowers hang as yellowish catkins, the female ones are tiny red brushes on the buds. Pollination is entirely by wind; insects play no part in it.

A single tree does bear, because male and female flowers sit on the same specimen. The crop is richer, though, when a second hazel stands nearby, because the flowering times of male and female often overlap only partly on the same tree. A common shrub hazel in a neighbour's garden also helps as a pollen donor.

The fruit differs markedly from the garden hazel. On the Turkish hazel several nuts sit tightly packed in a strongly slashed, bristly-spiny husk that turns brown in autumn and splits open. The individual nut is smaller than a cultivated hazel and has a strikingly thick, hard shell.

Harvest and use

The nuts are ripe from September, mostly CW 36 to 41. The easiest way is to wait until the clusters of fruit fall by themselves and gather them from the ground. If you want to get ahead, you can pick them from the moment the first ones turn brown and let them ripen off in the dry.

The honest note: the thick shell is tough, and an ordinary nutcracker meets its limits. In return the kernel is small but firm and aromatic, with the typical hazelnut flavour. For birds, squirrels and dormice the nuts are a feast anyway, so part of the harvest always goes to the neighbourhood in the branches. If you do not mind the effort of cracking, you get a nut that stores well and keeps for months in a cool, dry place.

Compared with the walnut, which needs a lot of space as a single tree and whose fallen leaves shape the soil, the Turkish hazel stays simpler and slimmer. It is more the tree for the edge of the plot, one that gives shade, feeds birds and casually drops a few nuts.

Care, pruning and health

Here the Turkish hazel makes it easy for you. A formative cut in the first years, shaping a clear framework of leading branches, is quite enough. After that a healthy tree needs no regular pruning. If you do cut at all, then in late winter, though you should keep in mind that hazels bleed heavily in early spring, so a cut in autumn or early summer is gentler.

Diseases and pests are rarely an issue with the Turkish hazel. It is considered noticeably tougher than the shrub hazel and is barely troubled by the usual problems. That makes it a tree you can largely leave to itself once it has taken.