American hazelnut hedge spacing - Ask Extension
Last fall we bought two young American hazelnut shrubs. This spring I plan to transplant them to the eastern edge of our fenced back yard, spaced so t...
Knowledgebase
American hazelnut hedge spacing #893450
Asked March 02, 2025, 6:01 PM EST
Last fall we bought two young American hazelnut shrubs. This spring I plan to transplant them to the eastern edge of our fenced back yard, spaced so they will grow together into a west-facing hedge. We're hoping to create a noise-reducing privacy screen that also produces nuts and attracts wildlife.
My question is how far apart to space the two plants. I have seen online recommendations of 3 feet to 12 feet apart. Again, our purpose is to create a dense hedge rather than two distinct trees. How close together can these shrubs be planted and remain healthy? Also, would 4 feet from the fence line give them sufficient room to grow? Our yard is not large, so we want the hedge as close to the perimeter as possible.
Thanks for your help!
Howard County Maryland
Expert Response
American Hazelnut is a suckering species, meaning that it can produce a group of stems arising from the root system some distance (eventually) from the original planting location. This natural tendency to spread a bit (they are not aggressive, so won't get out of control) means that they will fill-in the space between the two shrubs if they aren't placed too far apart. It's hard to predict how far each shrub will spread, and how much time it will take to get a certain width. The branch spread will generally be wider than the suckering diameter, and tends to be about two-thirds of the canopy height. Canopy height ranges anywhere from 8 to 18 feet tall, depending on site conditions and genetics.
Since you don't want to crowd the plants too early in life, where they will compete more for moisture, nutrients, and root space (heavy competition can stunt growth and hamper productivity of the nuts), it's a bit of a gamble as to how far apart to plant them, since it's impossible to predict what each individual plant will do as far as growth rate and mature size. For simplicity, if we assume that each shrub will mature around 10 feet tall and have a width of about 6 feet, then you'd probably want to plant them around 4 feet (perhaps 5) apart (center-to-center of the their current size, not canopy edge-to-edge). Sucker growth can help them fill-in over the years, and it's more likely they'd sucker in a sunny exposure compared to semi-shade. West-facing exposures tend to be pretty sunny in summer if there's no other trees/shrubs or buildings blocking the light.
A distance of 4 feet away from a fence might be a bit snug if you meant 4 feet from the center of the plant, but if you meant 4 feet from the plant's projected mature size, that should be fine. Plants never really stop growing; the national champion American Hazelnut, at least at the time of when one of our reference books was written, was a Maryland specimen around 20+ feet in both height and width. However, shrubs and trees do tend to slow down in growth rate as they get older, and since (over the long term) it's not uncommon among multi-stemmed shrubs for the oldest stems to die out as younger growth replaces them, at some point, their height becomes a bit more stable/stagnant.
Branches and roots will grow where they have room and the best access to light (branches) and moisture, oxygen, and nutrients (roots), so the shrubs would make do if you had to have them close to the fence. The consequences of that, though, may simply result in a shrub that progressively leans away from the fence if it needs more light or room for branch spread, and/or the roots enter the yard on the other side of the fence and spread suckers there. If the neighbors are fine with this, then there's no major issue with that, but if they didn't want that growth on their property, they could cut down suckers (not a big threat to plant health, but it might stress the plant if a lot of growth is removed). If they happened to try using herbicide on the suckers, that could damage much more of the plant on your side if they selected a systemic herbicide. Therefore, if you're wary of neighbor interference in the health of the plants, plant them as far onto your property (given the presumed mature size of the shrubs) as you are able.
The type of fence may also influence your decision on how far in front of the fence to plant them. A solid fence will be more restrictive to branching than an open fence. It will also reduce air circulation, which can help to try off leaves after rain/dew and reduce disease outbreaks since leaf surfaces that take longer to dry are more vulnerable to infection by disease spores. Although it's not a leaf spot type of infection, Filbert Blight is a fungal disease of concern for hazelnuts, though fortunately the native species is less susceptible to serious damage from this infection than European hazelnuts.
Miri
Since you don't want to crowd the plants too early in life, where they will compete more for moisture, nutrients, and root space (heavy competition can stunt growth and hamper productivity of the nuts), it's a bit of a gamble as to how far apart to plant them, since it's impossible to predict what each individual plant will do as far as growth rate and mature size. For simplicity, if we assume that each shrub will mature around 10 feet tall and have a width of about 6 feet, then you'd probably want to plant them around 4 feet (perhaps 5) apart (center-to-center of the their current size, not canopy edge-to-edge). Sucker growth can help them fill-in over the years, and it's more likely they'd sucker in a sunny exposure compared to semi-shade. West-facing exposures tend to be pretty sunny in summer if there's no other trees/shrubs or buildings blocking the light.
A distance of 4 feet away from a fence might be a bit snug if you meant 4 feet from the center of the plant, but if you meant 4 feet from the plant's projected mature size, that should be fine. Plants never really stop growing; the national champion American Hazelnut, at least at the time of when one of our reference books was written, was a Maryland specimen around 20+ feet in both height and width. However, shrubs and trees do tend to slow down in growth rate as they get older, and since (over the long term) it's not uncommon among multi-stemmed shrubs for the oldest stems to die out as younger growth replaces them, at some point, their height becomes a bit more stable/stagnant.
Branches and roots will grow where they have room and the best access to light (branches) and moisture, oxygen, and nutrients (roots), so the shrubs would make do if you had to have them close to the fence. The consequences of that, though, may simply result in a shrub that progressively leans away from the fence if it needs more light or room for branch spread, and/or the roots enter the yard on the other side of the fence and spread suckers there. If the neighbors are fine with this, then there's no major issue with that, but if they didn't want that growth on their property, they could cut down suckers (not a big threat to plant health, but it might stress the plant if a lot of growth is removed). If they happened to try using herbicide on the suckers, that could damage much more of the plant on your side if they selected a systemic herbicide. Therefore, if you're wary of neighbor interference in the health of the plants, plant them as far onto your property (given the presumed mature size of the shrubs) as you are able.
The type of fence may also influence your decision on how far in front of the fence to plant them. A solid fence will be more restrictive to branching than an open fence. It will also reduce air circulation, which can help to try off leaves after rain/dew and reduce disease outbreaks since leaf surfaces that take longer to dry are more vulnerable to infection by disease spores. Although it's not a leaf spot type of infection, Filbert Blight is a fungal disease of concern for hazelnuts, though fortunately the native species is less susceptible to serious damage from this infection than European hazelnuts.
Miri
