Performance of North American Hazelnut in Denver - Ask Extension
Curious about the performance of American Hazelnut versus Beaked Hazelnut in the Denver area - growth, water needs, tolerance to full south facing sun...
Knowledgebase
Performance of North American Hazelnut in Denver #868905
Asked May 17, 2024, 2:16 PM EDT
Curious about the performance of American Hazelnut versus Beaked Hazelnut in the Denver area - growth, water needs, tolerance to full south facing sun in Denver, nut production, wildlife support with an emphasis on insects e.g. lepidoptera, rather than squirrels.
Denver County Colorado
Expert Response
Both of these varieties can be grown in Denver. The Beaked Hazelnut is considered a more prolific producer, When looking at varieties, be sure it is tolerant to zone 4 temperature conditions. These trees can grow in full sun to full shade. Trees are wind pollinated and produce best if there are at least two trees for cross pollination. One fact to keep in mind is that they tend to sucker extensively. They need good loamy soil and adequate water, especially important that they receive water in Winter and during dry periods. The blossoms may also be susceptible to late spring freezes common to the Denver area.
This was not a helpful response.
It ignored my questions about these two species that are native to North America (I'm not interested in non-native varieties) e.g. wildlife support, water needs for Beaked vs American in this region, how they handle the higher elevations in Colorado relative to other areas, full sun will increase production but do they benefit from some afternoon protection like currants.
Based on this response I'm assuming there isn't much native plant knowledge here.
Also, I understand that the line between a shrub and small tree is rather arbitrary. But, especially given their tendency to form a thicket, I would think calling them (woody) shrubs would give a better impression of their growth habits to the general public than referring to them as trees.
We are sorry you didn't find our answer helpful. We don't have information about how these two species perform locally because they are not commonly grown or sold here; they are native to the east coast and much more common there in those moist conditions.
Neither of the arboretums at CSU or Regis grow American Filbert (Corylus americana) or Beaked Filbert (C. cornuta). Denver Botanic Gardens is growing both species at their York Street location but they were only planted recently so there isn't any data yet on how they will perform over time in Denver conditions.
Here is DBG's listing for their American Filbert:
https://navigate.botanicgardens.org/weboi/oecgi2.exe/INET_ECM_DispPl?NAMENUM=23739&DETAIL=1&startpage=1
and their listing for their Beaked Filberts:
https://navigate.botanicgardens.org/weboi/oecgi2.exe/INET_ECM_DispPl?NAMENUM=3285&DETAIL=1&startpage=1
As a side note, in my personal experience observing a non-native Turkish Filbert in Denver's City Park, it has fruited only once in about 30 years and the squirrels gobbled up the nuts.
Neither of the arboretums at CSU or Regis grow American Filbert (Corylus americana) or Beaked Filbert (C. cornuta). Denver Botanic Gardens is growing both species at their York Street location but they were only planted recently so there isn't any data yet on how they will perform over time in Denver conditions.
Here is DBG's listing for their American Filbert:
https://navigate.botanicgardens.org/weboi/oecgi2.exe/INET_ECM_DispPl?NAMENUM=23739&DETAIL=1&startpage=1
and their listing for their Beaked Filberts:
https://navigate.botanicgardens.org/weboi/oecgi2.exe/INET_ECM_DispPl?NAMENUM=3285&DETAIL=1&startpage=1
As a side note, in my personal experience observing a non-native Turkish Filbert in Denver's City Park, it has fruited only once in about 30 years and the squirrels gobbled up the nuts.
There is a lot to correct in this email
I grew a native American Filbert in Missouri (which is not on the East Coast but where it is native) that started producing nuts in 3 years and yes, squirrels like them, but not only squirrels. And, as I asked about in my original email, for other states I can find information about how they support other species like birds or lepidotera as discussed by the Missouri Department of Conservation
1) American Hazelnut (Corylous americana) has a range out to Kansas, up to Minnesota, and down to Louisiana
Claiming that they are an East Coast plant is problematic at best. Please stop reinforcing flyover stereotypes by ignoring areas outside the east or west coast with what you say.
2) Beaked Hazelnut (Corlyous cornuta)
Has an even greater range, which includes Colorado, as well as a Californian subspecies
Corylus cornuta var. californica
In fact, USDA Forestry Service lists Colorado first when running through communities where it is dominant in the page linked below
"Vegetation classifications describing plant communities where beaked hazelnut is dominant are listed below.
United States
Colorado:
thinleaf alder (Alnus incana subsp. tenuifolia)-beaked hazelnut/Fendler's waterleaf-Canadian white violet (Hydrophyllum fendleri-Viola canadensis) canyon shrubfield formations in Boulder County"
I grew a native American Filbert in Missouri (which is not on the East Coast but where it is native) that started producing nuts in 3 years and yes, squirrels like them, but not only squirrels. And, as I asked about in my original email, for other states I can find information about how they support other species like birds or lepidotera as discussed by the Missouri Department of Conservation
"Juvenal’s duskywing, a type of skipper, is one butterfly associated with American hazel. The spectacular Polyphemus moth uses a variety of larval host plants, but hazel is one of its favorites. The luna moth is another moth whose caterpillars eat hazel leaves, plus there are several noctuid and pyralid moths as well. The filbert worm — the larva of a type of tortricid moth — eats the nutmeats of hazel, acorns, beech, chestnut, and pecan"
I am glad to hear DBG has some planted; I hope that at some point they start supporting the development of native plant infrastructure like what you see from the Missouri Botanical Garden and their bi-annual native plant sale, which has been going on for nearly 3 decades
Or native gardens to show people ways to better reduce water use and support local ecology
