Shagbark hickory is an iconic tree species that holds great cultural, ecological, and historical significance. The name depicts its distinctive shaggy bark, which peels away from the trunk in long vertical strips.
It is a supportive tree for wildlife, offering protection and camouflage for insects and lichen, and food for birds and other herbivores. This marvel has numerous benefits for humans. So much so that there are ongoing preservation efforts for shagbark hickories.
Interested to know more? let’s take a look.
What You’ll Learn:
What is Shagbark Hickory?
Belonging to the walnut family, Juglandaceae, the shagbark hickory is a deciduous hardwood tree. It’s a multi-purpose tree native to North America, scientifically named Carya ovata due to the oval leaves. Ovata is Latin for egg-shaped.
It is found wild as far north as Maine, southern Quebec, Ontario, and Minnesota, as far east as eastern Texas, and south to Georgia.
The tree’s foliage consists of compound leaves with five to seven leaflets.
As with many deciduous trees, the foliage color changes along with the seasons. The spring and summer display is vibrant green, transforming into stunning shades of yellow and golden-brown in the fall, after which the leaves drop from the tree.
The trees typically reach heights of 80 feet or more. Specimens have been found exceeding this height, like the 150-foot tall tree in Savage Gulf, Tennessee. These trees are often described as towering, with straight, erect trunks that are almost perfectly round.
The bark, as you may have guessed, truly stands out. It has a rough texture that peels off in long strips as the tree grows and matures, giving the trunk a shaggy appearance that lends texture to the winter landscape.
These trees mature slowly, taking over 40 years, at which point they begin to produce nuts. The life span of shagbark hickories is long, and some are at least 400 years old.
The slow growth rate contributes to its longevity and ability to withstand changing environmental conditions. The tree develops a dense, strong wood resistant to decay, pests, and disease.
By growing slowly, the shagbark hickory can allocate resources such as nutrients and moisture to its full advantage, ensuring its overall health and resilience.
The fruit produced by this tree is a nut similar to other hickory nuts. It’s not surprising, seeing as it’s part of the walnut group. Technically, the nuts are drupes, meaning they have a fleshy outer layer, and a succulent middle layer surrounding a hard seed inside.
The nuts are enclosed in a thick outer shell, edible with a sweet, rich butter flavor, making them a versatile ingredient in cooking, baking, or roasted.
Propagating Shagbark Hickory
There are a few ways to propagate this giant. Grab your gardening tools and plan on practicing some patience. Remember, this tree is a slow grower.
If you grow by seed, assume that the resulting tree won’t be identical to the parent. Seed growing can be a fun project or a good way to start some rootstock, but it’s not the best method if you’re looking to replicate a tree exactly.
From Seed
The best time to collect seeds for propagating is in the fall when the fully ripe fruit drops to the ground.
Carefully remove the outer husk of the nut and place the nut in a jar or container filled with clean, untreated water. You might want to use rainwater, filtered tapwater, or allow the water to sit on the counter for 24 hours first to evaporate unwelcome chemicals.
Allow the nuts to soak for at least 24 hours but no more than 48 hours. Change the water every 12 hours to discourage pathogens from growing.
If you see floating nuts, remove them and discard them. These are not viable. Gently scarify the seeds by scraping them with a nail file or chipping them with nail clippers.
Give the nuts 90-120 days of cold stratification at about 35°F. This involves placing them in moist soil in a bag. Seal the bag and place it in the refrigerator.
After stratification, in six-inch pots filled with well-draining potting soil, sow the remaining nuts (seeds) and cover them with an inch of soil. Better yet, plant them in raised beds outdoors in the spring.
Work in some well-rotted compost and sand to the soil before planting.
Place the pots in a warm, sunny spot or use a heat mat to promote germination. The seeds need at least eight hours of light, so provide supplemental lighting or place them in an area with full sun.
Keep soil consistently moist but not soggy, as it will rot the seed. It can take several weeks to months for germination to occur.
Once the seedlings have developed a few leaves, harden them off and transplant them outdoors. These plants rapidly develop taproots, so don’t leave them potted for too long. That’s why direct sowing is best.
By Grafting
Grafting a shagbark hickory involves taking a branch of the desired tree, called the scion, and attaching it to a compatible rootstock.
The purpose of multiplying your stock via this method is to combine the desired characteristics with the vigorous root system of rootstock.
Shagbark hickories are often grafted so that the new tree inherits the unique bark texture, nut quality, and desired traits of the parent tree.
For success, it’s important to use a compatible rootstock. In this case, other hickories, such as mockernut (C. tomentosa) or pignut (C. glabra), work well. A walnut rootstock may also be used.
For grafting purposes, always use a mature and healthy shagbark hickory for the scion. Cut the grafting piece 6-8 inches long during winter when these trees are dormant. Take the cutting from the previous year’s growth.
Wrap the scion in a damp, clean cloth or paper towel and place it in a plastic bag. Store it in the refrigerator for up to a week until you’re ready to work.
Using clean, sharp tools, make a diagonal cut on the rootstock and a corresponding cut on the scion wood. These should be like a puzzle that fits together, with a “V” shape on the rootstock and a pointed tip on the scion.
They need to fit tightly together for this to work. You want as much of the material on both sides to press against each other as possible.
Using grafting tape, secure the top and bottom pieces together.
Do not use grafting compound or paint. While these are useful initially to help the wound stay moist as it heals, they end up causing problems down the road. Let your plant heal using its own natural methods.
Your job is to help the tree avoid stress. Keep the new tree well-watered and appropriately fed until the grafting succeeds.
From Cuttings
This method is relatively straightforward and enables you to skip the seed germination process and initial growing periods. It can also produce a genetic replica of the tree, unlike with seed growing.
Using cuttings means you are replicating new plants that are miniatures of the parent.
In the spring, choose a healthy specimen and select a pliable branch of about a quarter to half inch in diameter. Make sure this branch is disease and damage-free before cutting.
Using a sharp, clean cutting tool, slice the branch at an angle to remove it from the parent tree. Make the cut under a leaf node, which is where the leaves emerge.
Snip off the bottom two-thirds of the leaves from the cutting. Then, apply root growth hormone like Bontone II to the end to assist with root development.
In a pot containing a well-draining, water retentive growing medium, insert the cutting. Firm it in place.
Place the ccontainer in a bright area out of direct sunlight. Keep the soil moist at all times, but be careful not to overwater.
In about a month, signs of root formation should appear in the form of new growth. If you aren’t seeing any, gently use your fingers to dig down into the medium and lift the cutting up to examine the base for root growth. If none has started, it’s like the cutting failed.
Once at least one new leaf has formed, harden the cutting off and plant it in the garden. Remember, you don’t want to leave the new plant in a container for too long or you will shock the plant when you move it.
Caring for Shagbark Hickories
When caring for young shagbark hickories, you’ll likely need to water regularly, every 7-10 days, particularly during drought. Make sure the moisture penetrates to the roots. As the trees mature, supplemental water is less necessary.
Of course, every environment is different. Depending on how dry or windy it is, what the temperatures are, and if you receive any moisture, you may have to water more or less often. Your aim should be to water when the top two inches of soil dry out.
Once the tree is a few years old, it will have developed an extensive enough root system that it should survive without supplemental watering unless it’s a particularly dry patch.
Trees should be planted in full to partial sun in soil that is loose, well-draining and slightly acidic. Choose your location carefully because this tree does not transplant well. Those that are transplanted often suffer from diseases later on.
Prune to the desired shape and size during the dormant winter season. Never remove more than a fourth of the branches at a time. Remove diseased or damaged branches anytime you see them.
Use a slow-release fertilizer in early spring to promote health and growth. These plants are sensitive to changes in soil fertility, which is why a mild, slow-release option is best. Something formulated for trees, like Jobe’s Fertilizer Spikes, works well.
To assist with water retention, mulch around the base with an organic mulch like wood chips, compost, or leaf litter. Avoid mounding the mulch against the trunk as this can contribute to diseases.
Problems and Solutions
Regularly check the tree for pests and diseases. The faster you identify a situation, the more likely you can resolve it quickly and restore your tree’s health.
Shagbark hickories can be targeted by a variety of pests and diseases, though if you keep your tree healthy and unstressed, they are generally problem-free.
That said, the texture of their bark means they are a hospitable hiding place for many creatures, some of which bring pathogens along with them.
Pests
There are some interesting insects that can infest shagbark hickories. Close and regular inspection of all the parts of the tree is the first step in battling any unwanted guests.
Hickory Bark Beetle
The hickory bark beetle (Scolytus quadrispinosus) burrows into the trunk, causing weakness and damage. Small holes will appear in the wood of the trunk. As the infestation worsens, the leaves will turn yellow and many will fall from the tree.
The adults are about a quarter of an inch long and dark brown or black. They rarely attack healthy trees. Following the care guidelines laid out here to keep the tree healthy helps to prevent an infestation or any that do visit from seriously harming the tree.
Bait traps will help you capture some of the beetles, but there isn’t much you can do once a tree is infested beyond help support the tree’s health.
Insecticide sprays don’t work unless you apply them prior to infestation, so the beetle is poisoned when it first lands on the tree.
Walnut Husk Fly
Rhagoletis completa targets the nuts, causing them to rot. You might see premature shedding of the fruit, black areas on the outside, and the presence of the adult flies. When you open the shell, you’ll find larvae feeding on the inside.
The adult is about the same size as a housefly, but it’s more colorful, with green eyes, a bright yellow spot where the wings meet, and a brown body. The wings are banded. The female deposits her eggs inside the nut shell, where they hatch and start feeding.
Most home growers can ignore these, as they only cause cosmetic damage to the nuts. The nutmeat on the inside might have black staining, but they’re edible.
Good gardening hygiene when working with these trees is really all that is necessary when growing shagbark hickories in the home garden.
Remove all fallen nuts to reduce the population growth of the flies. Don’t leave any nuts out during the winter or the pest will use them as a place to overwinter. You can also lay a tarp down in the summer to catch the larvae as they drop from the tree.
Hickory Tussock Moth
Hickory tussock moths (Lophocampa caryae) are brown and cream moths that are found primarily in eastern North America. It’s not the adults that you need to worry about, though. It’s the fuzzy white and black caterpillars that emerge from the eggs the female lays.
These caterpillars can be almost two inches long, with extended “tufts” of hair, which are actually setae at the front and back. While these hairs might look cute, they’re a defense mechanism and can become embedded in predator’s eyes and skin.
The adults lay eggs during the summer, and the caterpillars are present during the fall.
The caterpillars feed on the trees and rob the foliage of nutrients, causing them to drop. That’s why early defoliation indicates that the hickory tussock moth larvae have reached the tree.
Typically, they aren’t too much of a problem, and since they are native, many predators will feed on them to keep populations in check.
Handpicking and disposing of the caterpillars is an effective method for small infestations, but be sure to wear protective gear so the hairs don’t become lodged in your skin, mouth, or eyes.
Hand-picking is ineffective on mature trees, so use a spray containing Bacillus thuringiensis (Bt) to kill the caterpillars. Bt is a beneficial bacteria that makes quick work of all kinds of larvae. Pick up some of Bonide’s Captain Jack at Amazon.
Diseases
You might encounter one specific, fairly common disease when growing shagbark hickories. Anthracnose is a disease caused by the fungus Gnomonia caryae, which can quickly take hold, though it rarely causes severe destruction.
The disease is indicated by dark, sunken lesions on leaves, stems, and nuts. Look for the reddish-purple lesions on the leaves, which are usually the first indication. These are typically followed by defoliation of the tree in cool, wet weather.
To help eliminate the disease, or at least reduce it, remove all fallen leaves and plant debris when it’s present. Dispose of this away from the garden and compost heap, or you risk re-introducing the disease.
Fungal sprays usually aren’t necessary, but if the disease seems to be progressing despite your efforts, use a copper-based spray or a broad fungicide like Monterey Complete Disease Control.
Harvesting and Storing
Shagbark hickories only produce fruit every one to three years, so don’t panic if yours skips a year or two.
The time to harvest is in the fall when the nuts are ripe and have started to drop to the ground. Get to them before the squirrels and nut weevils do. Collect fallen nuts as soon as you can. The husks will be green, so don’t wait for them to turn brown like some species do.
Now for the challenging part. One of the reasons growing shagbark hickories commercially never caught on is because it’s hard to get the nutmeat out. But once you do, you’re in for a treat. Some people call the nuts the “black truffles” of the nut world.
That’s because they have a rich flavor that’s something like a walnut and a pecan. Well worth the fight. Once you’ve gathered the nuts, give them a month to dry out. This will make the process easier.
Use a hammer or a heavy-duty nutcracker to break the thick outer shells open. Now, pry out the nutmeat. You can eat the nuts raw or roast them a bit to reduce some of the bitterness. Either way, they’re a rare treat.
Store your nuts in a dry, cool place in an airtight container in a spot away from moisture and pests such as mice.
Nutritional Profile
The nuts are rich in nutrients from protein, fiber, healthy fats, and vitamins B and E. They are packed with fiber and minerals like calcium, magnesium, potassium, and iron. These elements are important in bone health, weight management, and blood sugar regulation.
You could say this is an unrecognized superfood, particularly as the nuts have antioxidant properties to help protect the body from free radicles and stress.
What’s more, those healthy fats include monosaturated fats and omega-3 fatty acids—all good news for reducing cholesterol levels and improving overall cardiovascular function.
This tree grows well in USDA Growing Zones 4-8. The plant prefers cold winters and moderate summers.
Companion Planting
There are numerous plants that go well with this tree. Wildflowers are a natural, low-maintenance choice, as are native grasses like big bluestem (Andropogon gerardi) and blue grama (Bouteloua gracilis).
Underneath the trees, use shade lovers like ferns and hostas. Planting legumes like peas nearby can help fix nitrogen into the soil.
Other Species
Hickory trees come in various shapes and sizes. If you’d like to explore other species in the Carya genus, here’s a list to consider.
- Shellbark Hickory (C. laciniosa)
- Pignut or Black Hickory (C. glabra)
- Mockernut Hickory (C. tomentosa)
- Black Hickory (C. texana)
- Scrub Hickory (C. floridana)
- Red Hickory (C. ovalis)
- Bitternut Hickory (C. cordiformis)
- Sand Hickory (C. pallida)
- Vietnam Hickory (C. tonkinensis)
- Chinese Hickory (C. cathayensis)
- Nutmeg Hickory (C. myristicformis)
Shagbark Hickory Plant Info
- Hardiness Zones: 4, 5, 6, 7, 8
- Soil: Sandy, loam, some clay, PH between 5.5-8.0, well-drained
- Sun Exposure: Full sun, at least 6 hours of direct sunlight per day
- Planting:
- Harvest seeds in fall, stratify for 3-4 months, start indoors, transplant after hardening off
- Scion grafts should be taken in winter
- Cuttings should be taken in spring
- Spacing: 25 feet
- Watering: Young plants should be watered when the top 2 inches of soil dry out
- Fertilizing: Add balanced, slow-release fertilizer in the spring
- Common Problems: hickory bark beetle, hickory tussock moth, walnut husk fly; Anthracnose