Quercus macranthera Seeds | Caucasian Oak

Large, deeply lobed leaves and heavy acorns of the Caucasian oak in autumn light — Caucasian Oak (*Quercus macranthera*): Fagaceae, the Caucasus and northern Iran.

LATIN NAME: Quercus macranthera

COMMON NAME: Caucasian Oak

Plant Profile

Caucasian oak is the oak of the mountains between the Black and Caspian seas, and it is one of the hardest of the white oaks, surviving winters that would kill most of its relatives. It grows twenty to twenty-five metres with a broad, heavy crown of large, deeply lobed leaves that turn a good yellow-brown in autumn, and its acorns are among the largest in the genus. The bark is grey and furrowed, and old trees carry a massive, layered framework of limbs. It is a tree of deep upland soil and cold air, and it is rare in cultivation outside continental Europe. The leaves are among the largest of the white oaks, up to twenty centimetres long on young trees.

Science & Biotechnology

The species name refers to the long anthers of its male flowers, a detail that separates it from the closely related Q. robur at flowering time. It is a diploid white oak and hybridises with Q. robur and Q. petraea where their ranges overlap in the Caucasus, which has complicated the delimitation of wild populations. Provenance trials in northern Europe show it to be among the most cold-hardy of the white oaks, and it has been recommended as a forestry species for continental climates. Its large acorns store well, which makes it easier to handle than most oaks in a nursery. Its timber is also ring-porous and takes a stain well, which is one reason it was favoured for veneer.

Uses & Benefits

The wood is hard, heavy and durable and has been used in the Caucasus for construction, wheels, tool handles and fuel, and the bark for tanning. The acorns are large and, after leaching, have been used as food and fodder, though they are bitter. In the garden it is a big, dignified shade tree for a park or a large lawn, tolerant of cold and wind, and its autumn colour is better than that of most white oaks. It is also used as a rootstock in some eastern European orchards, where its hardiness is the point. In its native range it is a component of the Hyrcanian forests, the relict woodland belt along the Caspian slope, which is itself a conservation priority.

Growing from Seed

Sow acorns in autumn, two to three centimetres deep, and leave the pots outside for the winter; they need cold and they germinate early. The radicle emerges within weeks, so do not delay sowing once the acorns are ripe. Grow the seedling in a deep pot for two years, because the taproot is long and transplanting is the main cause of failure. Plant out into deep, well-drained soil in full sun, and keep the ground clear around the young trunk for the first three seasons. The acorns are heavy and fall close to the trunk, so collect them before the squirrels do. Weed control matters more than feeding in the first years.

Our Take

A big, cold-hardy oak with the largest acorns in the genus, and one that needs space and a long lease. It is a tree for a park, not a border.

Tree Seeds