Common Name: Caucasian alder
Type: Tree
Family: Betulaceae
Native Range: Iran, Transcaucasus
Zone: 5 to 8
Height: 50.00 to 80.00 feet
Spread: 25.00 to 50.00 feet
Bloom Time: January to April
Bloom Description: Female catkins mature from red to green, male catkins are pale yellowish-green
Sun: Full sun to part shade
Water: Medium
Maintenance: Low
Suggested Use: Shade Tree, Naturalize
Other: Winter Interest
Tolerate: Clay Soil, Wet Soil
Culture
Best grown in evenly moist, fertile, well-draining soils in full sun to part shade. Prefers part shade when young and can tolerate more sun as the tree matures. Tolerant of a wide range of soil types, including poor, clayey, and wet soils. Does not tolerate drought well. Hardy in Zones 5-8.
Noteworthy Characteristics
Alnus subcordata, commonly called Caucasian alder, is a medium to large, deciduous tree native to wooded gorges, stream banks, and river valleys in the Hyrcanian forests south of the Caspian Sea in northern Iran and west of the Caspian Sea in far southern Azerbaijan. Mature trees will reach 50-80' tall with an 25-50' wide, broadly oval to conical canopy of spreading branches. The young twigs and buds are covered in a dense layer of fine hair. The ovate to broadly elliptic foliage has irregular margins ranging from scalloped to singly or doubly serrate, slightly cordate to rounded bases, and will reach 2.75-6" long and 2.5-3.75" wide. The minute, apetalous flowers are held in separate male and female catkins. Pendulous, slender, 3-6" long, greenish-yellow male catkins hang from the branches in clusters in mid to late winter. The 1" long, ellipsoid, female catkins emerge in spring either singly or in groups up to five. They mature from red to green and finally form a dark brown, woody, cone-like fruiting structures holding samaras (winged seeds).
Genus name is the Latin name for alder.
The specific epithet subcordata means "almost cordate" in reference to the leaf bases.
The common name Caucasian alder refers to part of this trees native range. It can be found in the foothills of the Talysh Mountains in far southern Azerbaijan which is part of the Caucasus region.
Problems
Watch for sapsuckers such as aphids and scale. Most alders are susceptible to severe trunk and stem cankers.
Uses
Accent or specimen tree for lawns or parks. Fast-growing pioneer species suitable for naturalizing near streams or other low-lying areas. The persistent, cone-like fruiting structures and greenish-yellow male catkins offer horticultural interest in winter.