I’m sure I’m not the only one who had the thought “I didn’t know that butternuts grew on trees” when hearing of a butternut tree. Not to worry, the world is as it should be and butternut squash still grows on vines on the ground.
The butternut tree gets its name from the nut that it produces, which greatly resembles a butternut squash. The juglans cinerea, or white walnut tree, grows all over North America, yet is not super easy to come by. To better help find one on your next forest walk, read on to learn more about the butternut tree!
If you’re interested in other kinds of our gentle giant neighbors, read up on 101 Types of Trees from around the world!
Referred to as either butternut trees or white walnut trees, these deciduous beauties are native to the United States and Canada. Although it is not a staple tree in the average mesophytic forests (they’re often to be found growing as individuals) you may just stumble upon on by chance, if you know what to be looking for.
This tree is extremely slow-growing (only a few inches a year) and will grow to be an average of 20 meters in height — although it has happened that they grow to be over 40 meters tall. This is unfortunate, as they rarely live to be past 75 years of age. Live slow, die young, as they say.
What do Butternut Trees Look Like?
Butternut tree bark is light gray and rough in texture, a very generic type of tree bark. This is not the way to identify a butternut tree. The trunks are rather wide and sturdy, which leads to a generously open canopy, making them a decent shade tree.
In the canopy, you will find butternut tree leaves that alternately arranged and pinnately shaped. Each compound leaf contains anywhere between 11 and 17 leaflets that are around 3 inches long. The leaf texture is rather downy, and its color is more of a limey-yellow green than can be found on most trees.
A bit of an unusual detail, the leaf production of a butternut tree is tied to photoperiod rather than temperatures in the air. Whereas most deciduous trees lose their leaves once temperatures drop, the butternut leaf gets its dropping cue from the amount of daylight in the day.
In the fall, once the amount of daylight dips below 11 hours a day, the leaves of a butternut tree will fall. In the spring, once the amount of daylight reaches more than 14 hours per day, then the new flourish of leaves will sprout.
Where do Butternut Trees Grow?
A healthy butternut tree can only be found in certain regions of the United States and Canada. Their range extends from New Brunswick to southern Quebec in Canada, and they are spread from Minnesota to Arkansas, to northern Alabama.
Due to their growing preferences, they are completely absent from the deep south in the United States. Butternut trees are unfortunately very susceptible to forest fires, but they are rather resistant to wind storms.
What are the Growing Conditions of a Butternut Tree?
The butternut tree proliferates anywhere between 600-1500 meters above sea level, and this is because it is rather intolerant of consistent heat. The tree needs those cool nights that higher elevation regions can provide.
Butternuts prefer soils that are well-drained, and that is near stream banks or other bodies of water. Although it does occur that they grow in dry, rocky soils (certainly with origins in limestone), they are generally going to be found near stream benches, and in the talus fields of rocky slopes.
The butternut tree tends to grow as an individual, rather than in one giant butternut stock. Since they so seldom grow in groups, it is easier to find them in reference to the other hardwoods that they grow near.
However, it is important that there are disturbances in the forest canopy. The butternut tree cannot grow if it is hidden under a tight shade, and this classifies them as a very shade-intolerant species.
Mesophytic forests (forests that are neither too dry and hot, nor wet and cold) that contain:
- river birch
- sugar maple
- yellow poplar
- white oak
will probably also contain a small collection of butternut trees as well. In regions that don’t contain these trees, they will commonly be associated with:
- black cherry
- black walnut
- red maple
- sweet birch
- white ash
- white pine
- yellow birch
How do Butternut Trees Reproduce?
The butternut is a monoecious species, meaning that it possesses both male flowers and female flowers. However, it is unlikely that the flowers will mature both at the same time, and so it becomes necessary for pollinators to bring pollen from other mature trees for it to be properly pollinated. This means that butternut trees can be self-pollinating, but that is rarely the case due to delayed flower maturity.
The flowers of butternut trees develop as catkins, which are clusters of tiny flowers with indistinct or no petals found at the ends of twigs. The male catkins are staminate, bright yellow-green color and they develop from auxiliary buds. Female catkins are pistillate, with a light pink stigma, and they will grow on the current years’ shoots.
The fruit from a mature tree that comes from pollination is a nut shaped like a lemon. They grow in small bunches of 2-6, and the nut is encompassed by a green butternut husk. These fruits are one of the easiest ways to identify a butternut tree, and they are a delicious and edible nut!
How is Butternut Tree Wood and Foliage Used?
The wood of a butternut tree is very lightweight. It’s tightly grained and takes polish rather well, and it is highly resistant to rot, making it a favorite wood for woodcarvers. Due to its easy workability and attractive grain, it’s also a popular choice for furniture manufacturing as well.
The butternuts themselves are eaten by all sorts of small and large mammals, and birds that have the knowhow on how to remove the protective husk. Humans will also harvest butternuts and make them into oils for ointments.
The rinds of nuts have been used traditionally for many decades in natural dyeing as well. The husk or rind of the butternut nut contains a natural and vibrant orange dye. To concentrate the color, it may also be boiled with butternut bark.
Interestingly enough, in the early 19th century, folks who lived in areas with prevalent butternut trees — like southern Illinois and Indiana — were referred to as “butternuts” since most of their clothing was dyed the color of butternuts. During the civil war, that nickname was then given to confederate soldiers, as their uniforms were dyed using butternut pigment as well.
What Diseases are Butternut Trees Subjected To?
There is a disease called “butternut canker” that butternut trees are susceptible to. Originally thought to be brought on by the fungus melanconis juglandis, it was soon discovered that this fungus simply resulted in further infection to the tree. As we know, fungi are usually quite quick to infect vulnerable areas.
The main fungus culprit of a butternut canker disease is actually the sirococcus clavigignenti-juglandacearum. This parasitic fungus was brought to the United States in the early 20th century through an importation of infected Japanese walnut trees. However, Japanese walnuts appear to have disease resistance, and for this reason, in order to combat the disease, people have started making hybrids of butternuts and Japanese walnuts called “buartnuts”. These hybrids are disease-resistant trees, more capable of maturing into a healthy tree.
The butternut canker disease will begin by killing branches and stems of the lower canopy, where cankers will start to develop on an infected tree. These cankers are vulnerable wounds, where other types of fungi will start to attack the area, ultimately killing the tree within 5 years.
Another disease that butternuts are susceptible to is “bunch disease”. The main symptom of this ailment comes in the form of a “witches’ broom”. This appears as a dense mass of uncontrolled branch growth, kind of like cancerous cells, that start to appear in the canopy of the tree. These clusters fail to become dormant in winter and are eventually killed by frost. These dead branches then make the tree vulnerable, where fungus species will come in and infect the tree further.
Are butternut tree nuts edible?
Yes, they are! They are very oily nuts that are rich in nutrients and have been eaten by many Native American people for many centuries. However, since butternut trees are quite a few and far between, they are not a very common nut to snack on a forest walk.
Is butternut tree wood good for firewood?
Once the butternut wood is free of moisture, it can make good firewood. However, since the tree is not very common, and makes for a very attractive piece of furniture, many consider it to be a waste to burn a butternut tree for firewood.
How do you identify a butternut tree?
The easiest way to identify a butternut tree is in the summertime when its fruit appears. Butternut fruit is a lemon shaped green husk that encompasses a tasty and protein-rich nut.
How fast do butternut trees grow?
Butternut trees are a very slow-growing tree species, barely growing 5 inches in a year.
How long do butternut trees live?
Slow growing and short-lived, butternut trees seldom tend to live past the age of 75 years old.
Why didn’t my butternut tree grows nuts this year?
If a butternut tree grew nuts one year and not another, this is because they produce fruit in alternate bearing years. Trees are not like most flowers in that they flower every year in a specific season. For many species of trees, not every year will be a heavy crop yield. Some years they may not produce any fruit at all, or simply a lighter crop.
What does a nut from a butternut tree taste like?
It is said that a butternut nut resembles walnut in flavor – very mild, slightly sweet, oily, and fatty. A rich and tasty nut, eat can be eaten raw or cooked, young or mature.
How long does a butternut tree take to fruit?
A butternut tree will reach sexual maturity between 2-4 years of age and will produce fruit in alternately bearing years until the end of its life, which is around 75 years.
What does the bark of a butternut tree look like?
The bark of a butternut tree is light gray, with vertically arranged random fissures. The ridges between fissures are smooth and platy.
How do you open butternut tree pods?
Using a regular nutcracker will be successful in opening a butternut nut pod. Otherwise, using a knife, and something sharp to crack it open may work as well.
Where do butternut cankers come from?
Butternut cankers come from a fungal disease that attacks the butternut tree. The butternut canker disease works by killing branches on the lower crown of a tree, where they will start to develop these uncontrolled cankerous growths. These growths act as wounds, which then make the tree vulnerable to other types of fungus.
How long can butternut trees survive with a canker?
When a butternut canker develops on a tree, it means that certain branches of the tree are already dead. Once this happens, the entire tree will likely die within 5 years of the original cankerous developments.
How can you tell the difference between black walnut and butternut?
The easiest way to tell the difference between a black walnut tree (juglans nigra) and a butternut tree, is through its bark. The bark of a black walnut tree is much darker in color, though the texture is pretty much the same.
Additionally, you can tell the difference between the two trees by their fruit. The fruit of a black walnut tree is much more round in shape, whereas the butternut tree fruit is more shaped like a lemon.