A Complete Guide To Chestnut Oak – What You NEED To Know

Chestnut Oak is a deciduous hardwood tree native to Eastern North America. Scientifically known as Quercus montana, it grows 60-80’ tall & wide in full sun and well-drained soil, and it’s leaves host numerous pollinator larvae.  It’s leaves makes a beautiful orange-yellow display in Autumn & produces very large acorns that are favored by wildlife.

In this article:

• What is Chestnut Oak
• What are the pros and cons of Chestnut Oak
• Identification / Characteristics
• How to grow and care for Chestnut Oak
  • How to grow Chestnut Oak from seed
• What Wildlife, Pests, and Diseases effect Chestnut Oak
• Where to buy Chestnut Oak
• Uses of Chestnut Oak
• Final thoughts

What is Chestnut Oak

Also known as Rock Chestnut Oak, Mountain Chestnut Oak, I first encountered Chestnut Oak more than a decade ago while hiking on Massanutten mountain in Virginia when the acorns were dropping fast (and plunking me on the head). The acorns when falling were beautiful yellow-brown with red streaks, and I gathered some thinking they could make a good decoration. This was obviously when I was fairly botanically ignorant, as I was eventually disappointed when they dried to a solid brown. Nonetheless, this solid tree with interesting bark has many characteristics that we should admire.

One of the less thought of Oak trees, Chestnut Oak is mostly found on the ridges and mountain tops of Appalachia. An inhospitable environment for many plants, it is a medium size tree typically reaching 60-80′ tall. And it still cuts a stately appearance as it can grow where many other Oak trees cannot. It also has some of the most distinct bark, rivaling that of Shagbark Hickory or Hackberry. But this is definitely one of the most drought-tolerant of the Oaks.^{[1][2][3][4][5]}

The botanical name of Chestnut Oak was previously Quercus prinus, but was recently classified to Quercus montana in 2005.  So, in various references you should treat these names as synonyms.^[6]

Most often one would encounter Chestnut Oak in the wild on some lonely slope in the Appalachian mountains. You would notice it as you passed by and saw the thick, chunky bark. Or if you happened to get plunked on the head by a rather large strange colored acorn that was yellow with red spots. But the lumber made from this tree is valuable, as it is quite hard, durable, and rot resistant.^[7][8]

Native Range of Chestnut Oak

Natural habitat

The natural habitat of Chestnut Oak is on rocky mountain sides in Appalachia, dry upland locations such as bluffs, and other areas where few other Oaks can grow.^[4] And it is probably the most common Oak inhabiting the ridge tops of the Appalachian Mountains. 

I do a fair amount of hiking in the Appalachian Mountains in Pennsylvania and I frequently encounter Chestnut Oak on ridges and slopes, where it is often the dominant species.  In fact on the rockier sections of the Appalachian Trail I would say it is just about the most common tree. It does manage to grow in lower areas with more moisture, however these more hospitable environments provide more competition. 

Chestnut Oak Reference Table

Scientific Name	Quercus montana and Quercus prinus (synonym)
Common Name(s)	Chestnut Oak, Rock Chestnut Oak, Mountain Chestnut Oak
Native Range, USDA Zone	Eastern United States, USDA Hardiness Zones 4-8
Bloom Time	April
Bloom Duration, Color	Yellow-Green drooping catkin flowers
Height	50-70′
Spacing / Spread	50-70′
Light Requirements	Full sun
Soil Types	Sandy loam, loam, clay loam
Moisture	Dry to medium – must be well drained
Fauna Associations / Larval Hosts	Birds, mammals, numerous insects hosted

Pros and Cons

Pros

Height

Reaching heights of 60-70’ tall, Chestnut Oak makes an excellent shade tree.  It’s round crown is also attractive when grown in the open.^[2]

Interesting Bark

The bark of Chestnut Oak is very distinct.  It’s thick and chunky appearance give an indication as to the strength of the wood underneath. 

Fall Colors

Chestnut Oak makes a beautiful fall display. The numerous leaves produce by this tree makes for an impressive sight as a single specimen or as a forest.

Wildlife

Numerous forms of wildlife utilize this tree.  As Doug Tallamy shows in his book Natures Best Hope^[9], Oaks are the true keystone species hosting numerous pollinators.  Hundreds of species of butterfly and moth will lay their eggs on this tree.  And those caterpillars will in-turn feed numerous baby birds in Spring and Summer, further helping the food chain.

Finally in Autumn the acorns are a preferred food of Black Bear, Bluejays, chipmunks, raccoons, squirrels, whitetail deer, wild turkey, and other game birds.

Cons

Messy leaves

If grown in a residential setting where you wish to have a lawn, know that you will have to rake/relocate the leaves each fall.  Like all Oaks, they produce lots of leaves.  But remember, lots of caterpillars and butterflies overwinter in the leaves. Burning or throwing them away will kill them.  Perhaps try to just spread the leaves as a light mulch in your flower beds.

Large acorns

Chestnut Oak acorns are very large.  In fact they are just about the largest of any acorn.  So, if you have hard soil or a sidewalk, these can pose a hazard to walk on.  Now, if you have enough wildlife around, they will probably dispose of almost all acorns for you.

Identification and Characteristics of Chestnut Oak

Growth Rate

Depending on conditions Chestnut Oak will grow 12-24” per year, making it’s growth rate medium.^[2]  In the dense hardwood forests it will grow slower, as there is less sunlight available.  While if grown as a shade tree but in full sun conditions, it’s growth rate can approach two feet per year.

Seedlings can be particularly slower to grow, as the tree focuses on producing roots initially.  Seedlings germinated in an uncut forest were found to be only 6” on average after 10 years.  While those with some logging were 24”.  However, in optimum conditions, or at least full sun saplings were found to be about 60”-72″ tall after 10 years (on average).^[10]  Optimum conditions and adequate water should mean a much faster growth rate.

Height

Chestnut Oaks typically grow 60-80’ tall at maturity.  But in certain conditions they can get larger.  The largest recorded Chestnut Oak tops out at a whopping 144’ and is located in the Great Smoky Mountains National Park.

Trunk

Chestnut Oaks when grown in the open will make a straight trunk with alternate branching.  The crown will by pyramidal when young, and round to oval when mature. It is generally considered a very attractive shape.

Bark

Chestnut Oak has some of the most interesting and identifiable bark of all Oak trees.  It’s makes thick, chunky ridges with deep furrows.  The color ranges from brown to black, and often is gray. 

But this bark is easy to spot from a distance, and stands out compared to other Oaks with more generic bark such as Black Oak or Pin Oak.

Another interesting fact regarding Chestnut Oak bark – it is roughly 12% tannin and was used in the production of sole leather tannins quite heavily.^[3]

Leaf

Leaves of Chestnut Oak are typically 4-6” long by 1-1/2” to 3-1/2” wide, lanceolate to ovate in shape, dark green on the upper surface and white-green on the underside.  They have rounded dentate margins.^[3][4]

Overall the leaves of Chestnut Oak are very similar to Chestnut Trees and Swamp White Oak….however, Swamp White Oak leaves have white undersides while Chestnut Oak undersides are green. This is to say nothing of the different environments you find the trees in! With Chestnut Oak being on dry, well-draining rocky ridges and Swamp White Oak growing in moist lowlands.^[10]

Flower

Chestnut Oak trees are monoecious (male or female).  Flowers emerge in Spring from buds that are in the terminal bud cluster from the previous year’s shoots. 

Male flowers appear as dangling catkins, and female flowers are close at stem.^[2]  Like all Oaks, the flowers are not showy – they are just for reproduction.  The flowers are wind-pollinated, and do not rely on bees, butterflies or moths.

Acorns

Large crops of acorns each year, with bumper crops every few years.  In abundant years you can hear near-constant dropping of acorns in large stands of trees.

The acorns of Chestnut Oak are very large, over 1” diameter and long.

When do Chestnut Oak trees produce acorns?

Chestnut Oaks can produce acorn crops in as young as seven years old.  But typically will begin producing regular acorn crops at twenty years of age.^[2]

Root

Chestnut Oak initially develops a deep tap root, but will eventually lose it, changing to lateral roots.  Larger and mature trees will have 6-10 lateral roots that are extend roughly 10-30’ (3-10 m) from the crown up to depths of 36” (1 m). 

The root system generally extends to an area that is five times larger than the crown.  So, grown in the open this can make for a wide-spreading root system.

It has been documented that Chestnut Oak seedlings will have a higher root to shoot ratio than White Oak or Red Oak, and put more energy into root development over branching.  It is speculated that this may account for Chestnut Oak’s ability to adapt to dry or xeric sites.^[2][10]

Grow and Care for Chestnut Oak

Sunlight Requirements

Chestnut Oak will grow best in full sun, which is at least six hours of direct sunlight per day. It can also grow in partial shade, which is 4-6 hours per day.^[2]

Young trees that germinate in the forest are somewhat shade tolerant.  Meaning that for the first few years they can tolerate minimal sunlight.  However, if holes do not open in the canopy they will likely die. 

Soil Requirements

For soil texture, Chestnut Oak primarily needs a soil-type that drains well.  Sandy loam, loam, and silts.  In general is soil contains at least 15% silt, it will do well.^[2][3][4]

If you are unsure  of your soil’s drainage, you should consider testing it.  We have a detailed guide for testing soil drainage here.

Moisture Requirements

For moisture, Chestnut Oak does best in dry to medium-moist sites.  However the soil needs to be well-drained.^[2][10]

Chestnut Oak does not like wet feet or moist soil.

Maintenance

Chestnut Oak can be pruned in late Winter or very early Spring.  If you happen to notice a dead or dying branch, you can remove that anytime. But you may wish to cover the open wound with shade cloth or some breathable barrier, as this can help prevent insects from transferring disease.

But if the pruning is of your choice, do it in late Winter or early Spring.  Insects really are the primary vectors of most tree diseases, as they transfer spores and germs when they land on the open wounds.  Pruning at late Winter or very early Spring ensures they are not active, and allows the tree time to form scabs.

Fertilizer

Chestnut Oak will not require any supplemental fertilizer.

How to Grow Chestnut Oak from Seed

How to harvest Chestnut Oak acorns

Because Chestnut Acorns are prized by wildlife or at risk from insects boring into the nut, it is important to collect acorns not long after falling from the tree.  To do this, monitor the tree from late August into early October, as this is when the acorns will begin falling. 

When they fall, you must be quick.  Go out with a bag and gather up twice as many acorns as the number of trees you want.  Take them home and make sure the outside surface is dry to prevent mold.

If you wish to store the acorns, you can do so in a sealed plastic container in the fridge.  But do not let them get wet, and know that as part of the White Oak family it can sprout in humid environments.

How to determine acorn viability

Not all of the acorns you collect will be viable.  A significant number of them may be mal-formed inside, or have been compromised by parasitic larvae.  In fact Chestnut Oak acorns are often infested with larvae of nut weevils such as Conotrachelus sp. and Conotrachelus spp., and the moth Valentinia glandulella as well as several gall wasps.^[2] Thus, we need to make two tests to determine if the acorns will be viable.

First, we need to remove the cap of the acorn.  Do this by twisting it off or with the aid of a screwdriver. 

After removing the cap, examine the acorn closely and look for any holes.  If you notice a small hole present, discard the acorn as it is most likely infested with the larvae of a beetle, weevil, or some other insect.

The second test we must conduct is the float test.  This is where we drop our acorns into a container with water and wait a few minutes.  After several minutes have passed, remove any acorn that floats. 

The float test may seem a bit curious, but it’s purpose is to identify acorns that were deformed internally, or even aborted.  An acorn that doesn’t have it’s interior embryo form correctly or is aborted will be filled with air rather than the seed.  Thus, a bad acorn will float.  If interested, you can read a short article where I discuss some of the scientific literature backing up the validity of this test.

If you are interested in reading more on the accuracy of the float test, I’ve written up a summary of several published papers here.

Germinating and planting Chestnut Oak acorns

Chestnut Oks are a member of the White Oak family, and as such can germinate without any special conditions.  You can sprout in a moist towel or soil/sand mixture if you wish, or just plant them.

Sprouting Chestnut Oak acorns

Sprouting acorns before planting is a great way to know with 100% confidence that you have a viable acorn.  Note that it does help to soak the acorns in water overnight before starting. 

To sprout acorns, get a container with lid and some moist paper towels, or fill it half-way with a moist mixture of potting soil, sphagnum peat moss or sand. 

Place acorns into the mixture sideways, and press them in so they are about 1/3-1/2 into the mixture.  You can also use moist paper towels (moist, not wet).  Place a moist paper towel in the bottom of the mixture, then place a layer of acorns.  Then cover with another moist paper towel.

Place the container out of direct sunlight, and preferable in a cool dry place.  Check it daily for sprouted acorns.  Remove any that get moldy, and spray the towels or sand to keep it moist. 

Most of the time you will have a very high germination rate.

How to plant Chestnut Oak acorns

The following procedure works if you wish to sprout them, or just plant them after collecting them. 

Fill a suitable container at least 9” tall with moist potting soil.  Plant the acorns to a depth of 1-2”.   The acorn (sprouted or just collected) will grow a taproot during the remaining Fall months.

The container with planted acorns should go through a winter, as it does in the wild.  But there is a catch – if the acorn freezes solid, for prolonged periods it will not survive.  So, we can leave our container outside for the Fall, as long as it is protected from squirrels with hardware cloth or chicken wire.  But when the coldest part of winter sets in, you should take it inside of an unheated garage or shed.  If you live down South where freezing isn’t common or often, then you can leave it outside.^[11]

Just make sure that the soil needs to stay moist.  So, check your container periodically by picking it up to make sure there is still moisture present. Once the coldest parts of Winter are gone, you can take it back outside.

Caring for Chestnut Oak saplings

By mid to late Spring your acorns should have sprouted and be pushing through the soil.  Once they have made several sets of true leaves they can be planted out to their final location. 

If you planted multiple acorns per container, you may have multiple germinations per container.  In which case you should consider thinning or separating the seedlings.

While it is true that they can live in the container for a long time, it is best to plant them in the ground so that their taproot can continue to form.

Planting Chestnut Oak saplings

To plant an Oak Sapling, dig a hole twice as wide and 1.5 times as deep as the container.  Fill the hole with water and wait for it to fully drain (should take less than 60 minutes).

An optional step now is to throw a handful of compost into the hole.  This provides organic matter, and can help the seedling get established faster as well as provide some nutrients. 

Plant your sapling and backfill.  It is perfectly ok to throw in a couple more handfuls of compost when backfilling.

Direct sowing Chestnut Oak acorns

Chestnut Acorns can be direct sown in the fall. After collecting and testing viability (see above sections), you can plant the acorns 1-2″ deep. But, make sure you protect them with a screen or hardware cloth to prevent squirrels or raccoons from digging them up!^[11]

Protecting young saplings

Oak trees are frequently browsed by deer.  And racoons, skunks, and squirrels also like to dig up freshly planted trees.  So, it is necessary to protect them.

To protect them, I strongly recommend a tree shelter or cage.  You can purchase 4’ plastic tree shelters for less than $10 (less then $4 if you buy a lot).  These tree shelters will act as a miniature greenhouse, and stay on even after the tree outgrows them, which gives them further protection from deer rubbing their antlers on them.

Wildlife, Pests, and Diseases associated with Chestnut Oak

Pollinators

Although the flowers are wind pollinated, Chestnut Oak is still incredibly valuable in that it hosts hundreds of insect species.  Moths and butterflies lay their eggs in the leaves, which in turn hatch caterpillars that eat the leaves.  And birds eat these caterpillars and use them to feed to their young.  All native Oaks are considered a keystone species, meaning that they are just about the most important plant species for wildlife.^[9]

Birds

As noted above, birds eat caterpillars that are found in the leaves and feed them to their young.  But beyond that, Blue Jays and turkeys eat the acorns in the fall.

Older trees will also provide a place for cavity building birds to nest – Chickadees, House Wrens, Nuthatches, Owls, and Woodpeckers.^[10]

Other mammals

There are other wildlife that eat the acorns in fall.  Black Bear, Chipmunks, Deer, mice, and squirrels all consume the acorns.  Squirrels, burying many of them to dig up later for Winter food.^[2][3][10]

Deer and Rabbits

Deer will browse young foliage of Chestnut Oak and eat the saplings.^[10]  Rabbits may chew on the softer bark of young trees in the coldest parts of Winter when other food is scarce.

Disease

Yellowing leaves

If you notice the leaves of Chestnut Oak turning yellow before Autumn, it could be caused by chlorosis, which is a condition of iron deficiency.  It is often a symptom of high pH levels in the soil.  So, test your soil prior to planting, or consult an arborist for treatment options.^[2]

Oak wilt

Chestnut Oak is susceptible to oak wilt, which is a fatal disease beginning with die back of limbs and is often fatal.  This disease is spread by insects touching fresh wounds, so it is important to only prune oaks in late Winter (after the coldest parts have passed), but before insects emerge in Spring.

A twig-blight fungus (Diplodia longispora) is common among Chestnut Oak.  Also die-back or branch cankers in It’s northern range.  And although it is more resistant than other oaks, heart rot or branch rot fungi can attack it.^[2]

Other diseases that effect Chestnut Oak

A twig-blight fungus (Diplodia longispora) is common among Chestnut Oak.  Also die-back or branch cankers in It’s northern range.  And although it is more resistant than other oaks, heart rot or branch rot fungi can attack it.^[3]

Pests

The invasive Gypsy moth will attack Chestnut Oak, sometimes completely defoliating the tree.  This can be fatal.  Contact an arborist or your local ag extension office for treatment options.^[2][3][10]

Additionally there are canker worms, tent caterpillars, and the half-wing geometer that can defoliate the tree as well. There are some wood boring insects that can be harmful to Chestnut Oak.  Ambrosia beetles can be particularly damaging such as the Columbian Timber Beetle, Platypus & Xyleborus beetles.    And there are three timber worms that can be harmful.^[2][3]

Where you can buy Chestnut Oak

Chestnut Oak is not typically sold in nurseries, but occasionally it can be available. You can find specialty nurseries that deal in Native Plants on our interactive map.

Uses of Chestnut Oak

Landscaping with Chestnut Oak

Chestnut Oak can make for a great shade tree in a residential yard, provided it has adequate soil drainage. It can look great as a specimen, or as a grove.

Companion Trees

Chestnut Oak is often found with other oak trees and hardwoods.  Some trees that commonly are found with/near Chestnut Oak include Hickories, Sugar Maple, Tulip Tree, Sweet birch, Sweetgum, Black Cherry, Black Walnut, Red Maple.

Below is a list of companion trees to Chestnut Oak:

• Black Cherry
• Black Walnut
• Hickories
• Red or Sugar Maple
• Tulip Tree
• Red Pine
• Virginia Pine
• Other Oak trees (Red Oak, Black Oak, White Oak)

Understory plants

I’m going to list some common understory plants you can find growing under Chestnut Oak.  Note that these are trees and shrubs that grow underneath Chestnut Oak in mature hardwood forests!  Some of these plants will not do well in the sun or residential landscaping.

• Blueberry (low and high-bush)
• Blackberry
• Huckleberry
• Maple Leaf Virburnum
• Witchhazel
• Black Haw
• Spice Bush (only in full shade on dry sites)
• Partridge Berry

Lumber

The lumber made from Chestnuk Oak is strong, dense, heavy, and clear with a Janka hardness of over 1200 lbf (~5460 N).  It has been noted that it has better heartwood decay resistance than other oaks such as white oak, red oak, and black oak.^[2][7][8]

The bark of Chestnut Oak contains roughly 12% tannin, and was heavily used in the production of sole leather until roughly 1950.^[3]

Medicinal Uses

Unlike many other species, I have not been able to locate any medicinal uses for Chestnut Oak.

Native American Uses

The large acorns of Chestnut Oak were used for food by the Iroquois, and the bark was used to make a brown colored dye by the Cherokee.^[12]

Final Thoughts

Although not as popular as it’s larger cousins, Chestnut Oak is an important component of the Appalachian and piedmont ecosystems. It makes an impressive site lining the rocky ridges, and can also look great in residential landscaping. Furthermore, this tree has some of the most interesting bark with it’s large chunky appearance and deep furrows. The only drawback is that it does produce some of the largest acorns of any Oak tree, which could get messy in a yard or hazardous on a sidewalk.

Find more native trees here