common name: turkish filbert, turkish hazel
Scientific Name: Corylus colurna
This tree in Colorado These trees deal well with temperature extremes (zone 4), snowstorms and windstorms. Both the form and leaf shape closely resemble that of a littleleaf linden and therefore this tree makes an excellent substitute when a formal, medium sized, pyramidal tree is desired. Boulder has a nice row of established Turkish filberts and the current state champion (14” DBH). Their forestry staff plants several additional trees each year and has been impressed at how it has performed as a street tree.
Growth habit Has a densely pyramidal form when younger, very similar to that of a littleleaf linden. It is pyramidal-oval to almost round at maturity. Considered a medium sized shade tree, the mature size is approximately 40-50 feet in height with a 20-30 foot spread.
Foliage The attractive dark green summer foliage resembles that of a linden from a distance. The fall color is usually just a yellow-brown but a nice yellow color occurs periodically.
Fruit The filbert nuts develop inside an unusual bract that is actually a modified leaf.
Bark Besides the moderate size of this tree, the best characteristic is the mottled bark of gray, green, orange and brown. The interlacing of flaking bark makes it most attractive and desireable.
Insects and diseases The tree seems to be free from insect or disease problems. Even the aphids tend to feed elsewhere. When other species such as maples and lindens display scorch symptoms, the Turkish filberts remain green and vigorous.
Landscape value The tree is somewhat difficult to transplant and must receive supplemental watering for the first few summers. Once established it is quite drought tolerant. It is able to withstand somewhat alkaline soils but doesn’t like heavy clay soils that remain saturated.
Michael Dirr, Manual of Woody Landscape Plants (University of Georgia, 1990)
Michigan State University Extension
Colorado State University Extension