Maryland Native Plants
Juglans cinerea – Butternut
Planting and Growing
Juglans cinerea, commonly called butternut, is a small- to medium-sized tree that is best grown in full sun. Butternut is considered a lowland or riparian species and can often be found along riverbanks, in flood plains, swamps, and lowland forests. It should be planted in medium to moist soils but is considered drought tolerant. This species, like their relative the Black Walnut, produces an allelopathic compound called juglones. However, butternut produces it at such a low level that it does not impact nearby plants, even those considered “juglones sensitive” – see the Fun Facts section for more details!
Habit
Butternuts are a midsized canopy tree and are characterized by their short trunk and an open, sparsely foliated crown. Similar to Black Walnuts, they boast beautiful, pinnately compound leaves with 7-17 leaflets. They can be distinguished from the Black Walnut by their terminal leaflet. The bark of Butternut is ashy gray, at first smooth, soon divided into broad ridges, eventually deeply furrowed, the furrows separated by narrow, flat-topped ridges. Butternuts get their name from the large, ovoid fruits they produce in late fall. These edible nuts can grow individually or in clusters of 2 to 5, and have a sweet and oily taste reminiscent of butter.
Benefits to Wildlife
This species is a host plant for many species of lepidoptera including the Banded Hairstreak, Luna Moth, Regal Moth, Walnut Sphinx Moth, Banded Tussock Moth, and more. It is also the host plant for the Butternut Woollyworm. Additionally, these trees provide critical food and shelter to wildlife. Their highly oily, sweet nuts serve as an essential winter food source for squirrels, small mammals, and birds.
Imperial Moth
Regal Moth
Luna Moth
Butternut Woollyworm – photo by Bonnie Bell via the Maryland Biodiversity Project
Fun Facts
Butternut trees produce exceptionally rich, sweet nuts that taste similar to pecans.
The butternut tree is famous for the rich yellow and orange dyes its fruit husks and inner bark can produce.
Like maple trees, butternut trees produce a sweet sap that can be boiled down to make syrup. It has a unique, nutty flavor distinct from standard maple syrup.
Butternuts and Black Walnuts both produce a compound called juglones, and are therefore commonly considered to be allelopathic, or toxic to other plant species. However, our nursery staff have searched for scientific articles confirming the negative impact of the juglones compound on adjacent plant communities and have not found anything. The Morton Arboretum notes “that although it is ‘known’ as common knowledge in the gardening community, the allelopathic effect of black walnut has not been studied in depth. Much of what is known is based on one study done many decades ago. This means that any list regarding this topic is incomplete and some of the information may be anecdotal.” This is even more true of Butternuts and other related species, as they produce even lower levels of juglones than Black Walnuts do.
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Plant Information
Common Name: Butternut
Type: Tree
Family: Juglandaceae
Height: 40.00 to 60.00 feet
Spread: 40.00 to 60.00 feet
Bloom Time: May to June
Bloom Description: Yellowish-green
Pollination: Wind
Sun: Full sun
Water: Medium
Maintenance: Medium
Suggested Use: Shade Tree
Flower: Insignificant
Fruit: Showy, Edible
Tolerate: Rabbit, Drought
(Information from Maryland Biodiversity Project, Towson University, NC State Extension, and the Morton Arboretum)