Turkish Hazel
Basic Information
Common Name: Turkish Hazel
Scientific Name: Corylus colurna
Native Habitat: Southeastern Europe to Western Asia
History / Discovery / Cultivator
The Turkish Hazel, Corylus colurna, is a tree with a history deeply intertwined with both its natural distribution and its ornamental use. Its native range stretches from southeastern Europe, encompassing regions like the Balkans, up through Turkey and into parts of Western Asia, reaching as far east as the Himalayas. While the exact “discovery” of the plant isn’t attributed to a single individual in the way some other plants are, its existence has been known for centuries within these regions.
Historically, the nuts of Corylus colurna have been a food source, though not as widely cultivated for nut production as the common hazel (Corylus avellana). However, its primary value has always been its impressive form and resilience, leading to its extensive use as an ornamental tree.
The cultivation of Corylus colurna as an ornamental likely began in Europe during the 17th and 18th centuries. Its upright, pyramidal shape and dense foliage made it a desirable addition to parks and large gardens. There’s no specific “cultivator” to name, but rather a gradual appreciation and adoption of the tree by gardeners, landscapers, and botanists over time. Botanical gardens played a significant role in showcasing its features and promoting its wider planting.
One key factor that contributed to the Turkish Hazel’s popularity is its tolerance of urban conditions. It’s notably more resistant to pollution and compacted soils than many other trees, making it a particularly useful choice for planting in cities. This adaptability has been a major driver of its continued use in landscaping.
Furthermore, the Turkish Hazel exhibits good resistance to Eastern Filbert Blight (EFB), a fungal disease that severely affects the common hazelnut. This resistance has made it a valuable rootstock for hazelnut orchards, as well as a preferred choice for ornamental planting in areas where EFB is prevalent.
Over the years, selection for desirable traits has led to the development of various cultivars of Corylus colurna. These cultivars may differ in terms of their size, shape, and nut production. However, the species itself remains a popular and widely planted tree, appreciated for its stately appearance, hardiness, and relative ease of care. Its story is one of gradual recognition and appreciation for its inherent qualities, rather than a sudden discovery or the work of a single individual. It is a testament to the long-term value of a robust and adaptable tree that can thrive in a variety of environments. Its presence in landscapes around the world is a direct result of its inherent qualities and its ability to withstand the challenges of urban life, cementing its place as a valuable and enduring species.
Plant Care Summary
| Category | General Requirement | Notes |
|---|---|---|
| Light | Full Sun | Prefers at least 6 hours of direct sunlight daily. |
| Water | Moderate | Water deeply during dry periods, especially when young. Once established, it is relatively drought-tolerant. |
| Humidity | Moderate | Not particularly sensitive to humidity levels. |
| Temp. Range | Hardy | Extremely cold hardy, tolerating temperatures well below freezing. |
| Soil Type | Well-draining | Adaptable to various soil types, but prefers well-drained soil. |
| Fertilizer | Minimal | Usually doesn’t require fertilization, but a balanced fertilizer in early spring can promote growth. |
| Toxicity | Non-toxic | Generally considered non-toxic to humans and pets. |
Botanical Insights
Adaptations
The Turkish Hazel possesses several noteworthy adaptations. Its thick bark provides considerable protection against fire and physical damage. The tree’s tolerance of urban conditions, including pollution and compacted soils, is a significant adaptation for survival in developed environments. Its resistance to Eastern Filbert Blight is another key advantage, allowing it to thrive in regions where the common hazelnut struggles. The tightly packed crown and upright growth habit allow it to effectively capture sunlight, even in crowded environments. Furthermore, its deep taproot provides access to water and nutrients deep in the soil profile, making it more drought-tolerant than many other trees.
Propagation Methods
- Seed: Seeds require stratification (a period of cold, moist storage) to break dormancy. Germination rates can be variable.
- Grafting: Grafting is a common method for propagating desirable cultivars. It allows for the reliable reproduction of specific traits.
- Layering: Ground layering can be used to propagate Turkish Hazel, although it is a slower process.
Toxicology
Corylus colurna is generally considered non-toxic to humans, dogs, and cats. Ingestion of large quantities of the nuts might cause mild gastrointestinal upset, but serious reactions are very rare. The leaves and bark do not contain any known toxins that would cause significant harm if ingested. However, it is always advisable to prevent excessive consumption of any plant material.
Common Problems
Pests:
- Aphids
- Spider Mites
- Scale insects
Diseases:
- Powdery Mildew
- Leaf Spot (various fungal pathogens)
- Dieback (caused by stress or fungal infection)
Other:
- Iron Chlorosis: Yellowing leaves due to iron deficiency, often in alkaline soils.
- Nut Drop: Premature nut drop can be caused by stress, insufficient pollination, or pests.
- Slow Growth: Can be slow to establish, especially in poor soil conditions.
Rarity & Value
Rarity:
While not exceedingly rare in cultivation, mature, well-formed specimens of Corylus colurna can be difficult to find. Its relatively slow growth rate compared to some other trees means that it takes time to reach a significant size. Certain cultivars with specific characteristics, such as unusual leaf color or shape, might be considered more rare and sought after by collectors. Also, truly old and majestic examples of this tree in perfect form are becoming rarer due to urbanization and development.
Value:
The value of a Corylus colurna specimen is influenced by several factors. Larger, more mature trees generally command a higher price due to the time and effort required to grow them. Trees with a straight trunk, symmetrical crown, and healthy foliage are also more valuable. Cultivars with unique or desirable characteristics (e.g., weeping forms or unusual bark) will also fetch a premium. The current market demand for large, shade trees also plays a role in determining its value. Its relative resistance to pests and diseases compared to other similar trees also increase its desirability and market value.
