If you’re planning to add hazelnut trees to your garden, one of the first questions you’ll have is about their size. Understanding how tall do hazelnut trees grow is key for spacing, planning, and ensuring they thrive in your space.
Most hazelnut trees, which are often called filberts or cobnuts, are actually large shrubs that can be trained into tree form. Their ultimate height depends heavily on the specific type you choose and how you manage them.
This guide will walk you through everything that influences their height, from variety to pruning, so you can make the perfect choice for your yard.
How Tall Do Hazelnut Trees Grow
On average, most common hazelnut varieties (Corylus avellana) reach a mature height of 12 to 20 feet. When grown as a natural shrub, they often spread just as wide, forming a dense, rounded shape.
However, some types can suprise you and grow taller under ideal conditions. It’s important to remember that “hazelnut tree” is a bit of a catch-all term. The true maximum height comes down to a few critical factors.
Key Factors That Determine Hazelnut Tree Height
Several elements work together to decide just how big your hazelnut will get. You can control some of these, but others are simply built into the plant’s genetics.
Variety and Species: This is the biggest factor. European hazelnuts (C. avellana) tend to stay smaller, while American hazelnuts (C. americana) can be more shrub-like. The contorted filbert (C. avellana ‘Contorta’) is usually kept under 10 feet.
* Rootstock: Many commercial trees are grafted. A vigorous rootstock can push a tree to the taller end of its range, while a dwarfing rootstock will keep it compact, sometimes as short as 8-10 feet.
* Pruning and Training: This is your main tool for control. You can prune a hazelnut to be a single-trunk tree or let it grow as a multi-stemmed shrub. The choice directly impacts final height and shape.
* Growing Conditions: Like all plants, hazelnuts grow better with optimal sun, water, and soil. A stressed tree in poor soil may stay stunted, while a happy tree in rich, well-drained earth may reach its maximum genetic potential.
Popular Hazelnut Varieties and Their Typical Heights
Here’s a quick look at some common choices and their expected mature sizes. This will help you narrow down your selection.
European Hazelnut (Corylus avellana)
This is the most common type for nut production. They are typically grown as a bushy shrub but are easily trained to a single trunk.
* ‘Barcelona’: A very popular variety. It grows vigorously to 15-18 feet tall and wide if unpruned.
* ‘Ennis’: Known for large nuts, it has a similar growth habit to ‘Barcelona’, reaching 15-20 feet.
* ‘Hall’s Giant’: True to its name, this is a robust grower that can easily reach 18-20 feet tall.
American Hazelnut (Corylus americana)
This native species is more often grown as a wildlife shrub or for its brilliant fall foliage. It’s generally more shrub-like and spreads by suckers.
* It typically grows 8-15 feet tall, but often forms thickets wider than it is tall through its suckering habit.
Contorted Filbert (Corylus avellana ‘Contorta’)
Also known as Harry Lauder’s Walking Stick, this is grown for its fascinating twisted branches, not for nuts.
* It is a slow-grower and usually maxes out at 8-10 feet tall and wide, making it a good ornamental choice for smaller gardens.
How to Manage and Control the Height of Your Tree
You are not at the mercy of your tree’s genetics. With smart practices, you can manage its size effectively.
Pruning for Shape and Size Control
Pruning is essential. The best time to prune is in late winter when the tree is dormant. Here’s a simple approach:
1. Year 1-3 (Establishment): Choose 5-7 strong, well-spaced main branches to be your framework. Remove any weak, crossing, or inward-growing shoots.
2. Annual Maintenance Pruning: Each year, cut back the previous season’s growth by about one-third. This encourages branching and keeps the tree compact.
3. Sucker Removal: If your tree is grafted, promptly remove any suckers growing from the base below the graft union. For American hazelnuts, you’ll need to remove suckers regularly to prevent thicket formation if you want a single plant.
Training as a Tree vs. a Shrub
* Single-Trunk Tree: Select one strong, central leader and remove competing stems. This creates a classic tree form that can make harvesting easier and allows for underplanting.
* Multi-Stemmed Shrub: This is the natural habit. It requires less initial training and can create a great privacy screen or windbreak. It will, however, take up more lateral space.
Spacing and Planting Considerations
Always plan for the mature size, not the size of the sapling you bring home from the nursery. Proper spacing prevents overcrowding and reduces disease.
* For nut production: Space trees 15-20 feet apart if you are training them as single trunks.
* For a hedgerow or shrub border: You can plant them closer, about 8-12 feet apart, and allow them to grow together.
* Remember: They need full sun for best nut production—at least 6-8 hours of direct sunlight daily. Planting to close to a building or under large trees will limit their growth and yield.
Common Problems That Can Stunt Growth
Sometimes, a hazelnut tree not reaching a reasonable size is a sign of a problem. Here are a few culprits:
* Eastern Filbert Blight (EFB): This is a serious fungal disease that can kill branches and entire trees, severely stunting them. Plant resistant varieties like ‘Jefferson’ or ‘Yamhill’ if EFB is in your area.
* Poor Soil and Drainage: Hazelnuts dislike “wet feet.” Heavy, waterlogged clay soil will cause root rot and poor growth. They prefer well-drained, loamy soil.
* Lack of Pollination: Hazelnuts are not self-fertile. You need at least two compatible varieties for cross-pollination to get nuts. A lonely tree might not grow with the same vigor, though it will still grow.
FAQ About Hazelnut Tree Size
How fast do hazelnut trees grow?
They have a moderate growth rate, typically adding 1 to 2 feet per year under good conditions once established.
Can I keep a hazelnut tree small?
Yes, absolutely. By choosing a naturally compact variety and committing to annual pruning, you can maintain a hazelnut at 8-10 feet tall. Some dwarf varieties are even smaller.
What is the spread of a hazelnut tree?
The spread is usually equal to its height, especially when grown as a shrub. A tree pruned to a single trunk will have a narrower spread, more like 10-15 feet.
Do hazelnut trees have deep roots?
Their root system is relatively shallow and fibrous, spreading widely near the surface. This makes them good for erosion control but means they need watering during droughts.
How long until a hazelnut tree produces nuts?
You can expect your first small harvest about 3-4 years after planting, with good production starting around year 6-8.
Choosing and growing a hazelnut tree is a rewarding long-term project. By starting with the right variety for your space and goals, and using pruning as your primary tool, you can enjoy both its beauty and its harvest for many years to come. Remember, the answer to “how tall do hazelnut trees grow” ultimately lies in your hands as much as in the seeds.