Shagbark Hickory

(Carya ovata)

I ruined many good white T-shirts, when I was a boy, harvesting hickory nuts in fall by creating a makeshift bag out of my T-shirt. The neighborhood kids and I would then sit in a circle around whomever was cracking the nuts waiting to get tiny bits of the sweet nutmeats.

The Shagbark Hickory is a member of the walnut family, Juglandaceae. The genus name, Carya, is the Greek word for walnut. The species name, ovata, is Latin for ovate or round for the shape of its fruit (nut). The common name refers to the way the bark of the tree curls away from the tree in long plates, giving the tree a shaggy appearance. Other common names for this tree are Scalybark Hickory, Shellbark Hickory, and Upland Hickory. The genus Carya is composed of pecans and hickories. These trees are medium to large, long-lived, deciduous trees with tall trunks. The Shagbark Hickory grows to an average of 60 to 90 feet with a spread up to 45 feet. The Champion Tree is in Sumter National Forest in South Carolina. It is a massive 153 feet tall with a 3-foot diameter trunk.

This tree instills patience. When planting a Shagbark Hickory tree, you are planting a tree for future generations to appreciate. It is slow to grow and slow to mature. It sometimes takes 30 to 40 years to produce its first good crop of nuts. Also, extracting the nut meats is extremely tedious and time consuming. But, on the upside these trees can live hundreds of years.

Description

The Shagbark Hickory is like the walnut. It is a tall tree with pinnately compound leaves, but the Shagbark only has 5 to 7 (usually just 5) leaflets. The final 3 leaflets are larger than the rest with the final leaflet being the largest. The smooth, glossy, yellow-green leaves are arranged alternately and are 8 inches to 14 inches long with an 8-inch to 12-inch spread. The leaflets are broadly ovate to elliptic with pointed tips and finely serrated edges. Each leaflet has tufts of hair at the tip of each tooth along the leaf margin. In fall, the leaves turn brilliant golden yellow and then end in a deep golden brown before dropping.

The thick, crooked twigs are red brown to light grey and end in large, hairy brown, terminal buds with 2 to 4 overlapping scales. The Shagbark Hickory’s branches are large and stout with dark grey bark. Branches start high on the tree and form in alternate positions ascending the tall straight trunk.

Male (staminate)flowers are 3-to-6-inch, pendulous, green, hairy catkins. Female (pistillate) flowers are short, 1/8-inch, conical spikes at the tips of young shoots. Both flowers open when the leaves are nearly full-sized in March, but the male catkins first appear in late fall.

The fertilized fruit of the Shagbark Hickory form in clusters of 1 to 3 at the end of the branches. These fruits are nearly round edible nuts. The nuts are covered in a thick, dark-green husk that is flattened at one tip and divided into 4 equal sections with indented margins. The husk or involucre turns brown to brownish-black when mature and splits at the base when ripe. The boney nut inside the husk is light- brownish white and has a relatively thin shell enclosing a sweet edible seed.

The bark of young Shagbark Hickories is smooth and gray, but as the tree ages, the bark becomes more ragged and begins to exfoliate into 1-to-3-inch strips up to 12 inches long. These strips or plates of bark curl outward at each end, thus giving the tree its distinctively shaggy or rough unkept appearance. 

These trees have extremely long taproots with spreading lateral roots. The taproots can sometimes be   1 1/2 times the length of their trunks as young saplings 3 to 6 feet tall. This fact makes the trees difficult to transplant in a nursery or orchard setting.

The overall habit of the Shagbark Hickory is an irregular oval shape with a wide top running 2 to 4 times longer than broad. The crown is rounded with leaves formed in large clumps down the tree.

Identifying Factors

1. The exfoliating planks of bark is the most distinguishing characteristic.
2. The compound leaves, usually made up of 5 leaflets, turn vibrant yellow or gold bronze in fall before dropping.
3. The leaves of the Shagbark Hickory are aromatic. They have a faint scent of apples when crushed, whereas other hickories smell astringent.
4. The husks of the nuts are split at the base into 4 sections and have indented margins.

Habitat /Range /Zone

Shagbark Hickories tend to grow along river bottoms, on upland slopes, at the edges of mixed hardwood forests, in moist fertile valleys, on mountain ridges, and sometimes in open fields. Shagbarks range across a broad region of North America. They are found from southwest Quebec Canada, east to southern Maine, southward to northern Florida, westward to eastern Texas and northward to southeast Minnesota. The only exception to this broad range is a few clusters growing along the southern Gulf Coast and lower Mississippi Valley. These trees live in zones 4 through 8 and have good cold hardiness down to -40 degrees Fahrenheit. They prefer a humid climate but can adapt to a wide range of climatic conditions. They are also somewhat resistant to fire damage, even more so than maples.

General Culture

Shagbark hickories like full sun to partial shade. They prefer deep, loose, loamy, well-drained soils because of their deep tap roots, but they can tolerate other soils, even heavy clay soils. They do not like sandy soils. Their tap root grows faster than the stem above ground, sometimes 2 to 3 feet the first growing season. They like a habitat where the soil is evenly moist through the year.

Irrigation & Fertilization

Water your young tree thoroughly once a week until it is well established. After that, the tree should be fine except in times of drought. By keeping your tree well-watered it is less likely to have pest problems.

Fertilize your tree once a year, in early spring, after it has become established. Continue fertilizing every spring until it begins bearing nuts at about 10 to 15 years of age. Use a balanced granular fertilizer like 10-10-10 at the rate of 1 pound per caliper inch of trunk (i.e. a 3-inch caliper tree would take 3 pounds of fertilizer). Do not use a high nitrogen fertilizer as this will cause excessive foliage growth and less nut production. Each year spread the fertilizer out evenly to just beyond the drip line.

Pruning & Training

No pruning is required on Shagbark Hickory trees. They only require periodic removal of crossed branches and damaged or diseased limbs.

Pollination

Shagbark hickories are monoecious, meaning both male and female flowers are produced on the same tree. Male flowers are long, narrow catkins that hang freely in groups of 3 from each stalk. Female flowers appear at the tips of twigs in groups of 2 to 5. The flowers develop with the leaves in late April or early May. The primary means of pollen dispersal is by wind. Shagbark hickories are self-fertile, but yields can benefit from planting more than one tree.

Propagation

Hickories grow best when planted from seeds (nuts). Nuts can germinate without a cold treatment, but a period of cold stratification is recommended.

Collect the nuts in fall and soak them in room temperature water for 2 to 4 days. Make several water changes during this period as the water gets clouded with tannins. Let the nuts dry for a day. After they have dried, place them in plastic containers of moist sand. Keep the nuts refrigerated for 90 to 150 days. Cold stratification for 90 days at 30- to 40-degrees Fahrenheit seems to be optimal for the best germination.

Pest & Disease

Shagbark Hickory trees are vigorous and, if undamaged, usually have no serious pest or disease problems. Normally they live trouble-free and rarely need any special care. But they can be affected by a long list of diseases such as anthracnose, crown gall, powdery mildew, and viral bunch disease. These trees are the most susceptible to canker rot fungus, so be sure to scrape out any soft, discolored wood before this fungus gets a toehold in the tree.

Just like diseases, pests seldom threaten these tree’s long-term health, although they can be affected by up to 180 different species of insects and mites. Hickories can be seriously damaged by a few pests such as caterpillars, leafhoppers, twig girdlers, pecan weevils, lace bugs, and aphids. But, the most potentially damaging to the entire tree is the hickory bark beetle. Nut production can be adversely affected by such pests as hickory nut curculios, pecan weevil, and shuck worms, which can cause premature dropping of nuts.

Harvest & Storage

It is best to gather hickory nuts before they fall to the ground, otherwise you will be competing with our wildlife friends. The nuts ripen in September and October. The outer husk on the nuts will start to split and can be removed easily once they are ripe.

To harvest the nuts lay a tarp or old sheet on the ground and shake the tree vigorously. It may take several attempts over the course of a few weeks to gather most of the nuts. Or, you can be daring and wait until after a windy day to pick the nuts up off the ground, but the squirrels may get there first.

Let the nuts cure for about 3 weeks in a protected area before storing them or beginning to eat them raw. Remove the husks, then crack the outer shell of the nuts with a hammer while wrapped in an old towel or with a nutcracker.

The nuts can be stored in a cool place for 3 to 6 months if left in their shells. The shelled nut meats can be kept refrigerated in an airtight plastic bag for up to a week or they can be stored frozen for up to a year.

Culinary Uses

Hickory nuts can be eaten raw out of your hand or added to salads and savory dishes like walnuts. The nut meats are sweet and nutty with a unique flavor. The nuts can be ground up to make flour, candy, and a nut milk like almond milk. They can also be used in baking muffins and cakes like pecans. A porridge can be made by boiling down the ground nut meats and the oil that forms can be skimmed off to make a nut butter.

A complex flavored syrup can be made in 2 different ways from the Shagbark Hickory. The sap can be boiled down to make a syrup like when making maple syrup. In the second method, pieces of the bark are boiled down and simmered to make an amber-colored simple syrup that has a smoky, earthy flavor.

Charcoal made from hickory wood is renowned for its wonderful hickory flavor when smoking meats such as bacon and ham. It is also used when grilling barbeque.

Nutritional Benefits

Hickory nuts are teaming with vitamins, minerals, protein, fiber, and good carbohydrates. The nuts are full of vitamin A, vitamin C, Vitamin B-6, vitamin B-1, and fatty acids. They are also a good source of potassium, iron, calcium, phosphorus, magnesium, and dietary fiber.

These nuts are excellent appetite satisfiers and can enable people to lose weight by fighting off urges to overeat. Their complex carbohydrates provide a steady source of energy and ward off fatigue by preventing sudden insulin fluctuations. The nuts high fiber content improves gastrointestinal health and digestion.

Cardiovascular health can be improved by eating hickory nuts because the nut’s oil balances good and bad cholesterol. They increase good cholesterol (HDL) and decrease bad cholesterol (LDL). Their high fat content and vitamin B1 optimize the function of vital systems such as the cardiovascular, nervous, and musculoskeletal systems. The minerals, calcium, magnesium, and phosphorus found in hickory nuts also improve bone density.

Native American Uses

Hickories, just like walnuts, were used in multiple ways by native peoples. The most important use, of course, was as a food source. The word hickory is derived from the Algonquian word, “pawcohiccora”, describing an oily nut milk made from pounding hickory nut kernels that had been boiled. This sweet nut milk was used by the Creek in their hominy and corn cakes.

Many tribes ate the nuts raw as a seasonal treat and others boiled the nuts down to make a cooking oil. The Winnebago, Dakota, and Cherokee boiled down the nuts along with their shells to create a soup. In areas where there were no maples or sycamores, hickory sap was used to make a sweetener and syrup. The Iroquois boiled and ground up the nuts to make baby food and mixed this same mash in with their corn pudding or corn soup. Many tribes ground the nuts to make a nut meal to make different breads. Ground nuts and honey were also used as a breakfast food. The Cherokee, Meskwaki, and many other tribes dried and stored the nuts for winter use.

Native Americans also used hickories medicinally. The Ojibway and Chippewa peoples steamed the young shoots and leaves to make a drug to treat headaches and convulsions. The Cherokee chewed pieces of hickory bark for sore mouth and throat ailments. The Potawatomi applied the liquid from boiled bark to sore muscles and arthritic joints. Other tribes made hickory bark infusions to keep their muscles pliable during hunting and athletic events. The Iroquois mixed hickory sap with bear grease to make a bug repellent.

Tribes had a great amount of uses for hickory bark as fiber for basketry and bindings. The wood was used for hunting supplies, implement handles, and building. The Cherokee utilized the inner bark for chair bottoms and baskets. Whereas the Iroquois and Omaha used the bark to make snowshoe lashings as well as using the wood to make the rims of their snowshoes. Hunting supplies such as arrow shafts, blow gun darts, and bows were made from the strong elastic wood. The Seminoles and Cherokee made barrel hoops, tool handles, and containers from the wood.

Ornamental Uses

Shagbark Hickories have limited uses in most landscape settings. But, because they do make an attractive large shade tree with interesting bark texture and open branching, they can be a unique specimen tree. Hickories are best utilized in parks, or naturalized locations like pastures or at the edge of open woods.

They do not make good lawn or street trees because of their slow growth, leaf litter, and nut production. It is best to plant them well away from buildings, sidewalks, driveways, and parking lots. Falling nuts and nuts on pavement can be hazards as well as their litter can be a landscape maintenance nightmare. Also, the tannins from the nut husks can stain concrete surfaces.

Other Uses

Hickory wood is wonderful as firewood, for charcoal production, and for barbecuing. The wood has a high efficiency level when burned making many BTUs per pound burned. It burns for a long time with little or no smoke. The wood is also prized for its strength, hardness, and resistance to impact.  Hickory wood is used for tool handles, furniture, agricultural implements, gun stocks, baseball bats, and construction timbers.

Hickory nuts are a good source of food for wildlife. Squirrels, chipmunks, bears, foxes, rabbits, field mice, deer, rabbits, turkeys, ducks, and quail feed off the nuts. Bats even live in the bark plates.

American settlers made wagons, wagon wheels, cabin doors, and farming tools from the fine wood. Settlers also made a yellow dye from the inner bark.

Related Varieties & Recommended Varieties

Eleven of the world’s 25 hickory species live in North America. The shagbark hickory (Carya ovata) is the most common hickory in the Southeastern US. But there are 4 other common hickory varieties:

Shellbark Hickory (C. laciniosa) – is like the shagbark but is found in wetter soils and has larger nuts. The leaves are also larger and have 7 leaflets with orange twigs. Shellbarks grow 70 to 90 feet tall.

Mockernut Hickory (C. tomentosa) – has 7 to 9 leaflet per leaf. Their nuts are smaller and harder to crack. Mockernut bark is smooth with diamond shaped furrows. They grow 50 to 70 feet tall.

Pignut Hickory (C. glabra) – has 5 to 7 leaflets per leaf and their nuts are much smaller with a bitter astringent aftertaste. Pignuts grow to 50 to 60 feet.

Bitternut Hickory (C. cordiformis) – has 7 to 9 leaflets per leaf and small nuts so bitter that squirrels usually don’t eat them. They grow to 50 to 75 feet.

There are also two other sub-species of the shagbark, Carolina Hickory (C. ovata var. australis) and Southern Shagbark (C. carolinea-septentrionalis).

There are several cultivars of shagbark hickories that have been selected for flavor and cold hardiness over several decades: ‘Grainger’ from Tennessee, ‘Wilcox’ from Ohio, ‘Ben’s Big Sweetie’ from Illinois, and ‘Harold’ from Wisconsin.

Pecans (Carya illinoinensis) are also in the same genus with hickories. There is a pecan and hickory cross called a hican. These two trees were crossed for nutmeat size and cold hardiness. Some varieties are ‘Palmer’, ‘Burton’, and ‘Pixley’ that has good flavor and has promise as a landscape tree.

Hazards & Cautions

As mentioned earlier, hickories are messy trees. Because of the amount of leaf litter, nut litter, and staining nut husks, they should not be planted near structures, walkways, or paved areas. Their roots can also break-up concrete and asphalt pavements by heaving.

The nuts can pose a chocking hazard to small children. Also, people with nut allergies should be aware of possible problems.

References & Related Links                                                                                                 

1. Bacon, Josephine; Clifton, Claire; Conner, David; Fielder, Amy; et al. National Geographic Edible: An Illustration Guide to the World’s Food Plants. Global Book Publishing: Lane Cove, Australia, 2008.
2. Bennett, Chris. Southeast Foraging. Timber Press: Portland, 2015.
3. Dirr, Michael A., Heuser, Charles W. The Reference Manual of Woody Plant Propagation: From Seed to Tissue Culture. Varsity Press: Athens, GA, 1987.
4. Kershner, Bruce; Mathews, Daniel; Nelson, Gil; and Spellenberg, Richard. National Wildlife Federation: Field Guide to Trees of North America. Sterling Publishing: New York, 2008.
5. Kirkman, L. Katherine, Brown, Claude L., and Leopold, J. Donald. Native Trees of the Southeast: An Identification Guide. Timber Press: Portland, 2007.
6. Little, Elbert L. National Audubon Society: Field Guide to North American Trees – Eastern Region. Albert A. Knopf: New York, 1980.
7. McCreary, Rosemary. Taylor’s 50 Best Trees: Easy Plants for More Beautiful Gardens. Houghton Mifflin Company: New York, 1999.
8. Peterson, Lee. Peterson: Field Guide to Edible Wild Plants of Eastern & Central North America. Houghton Mifflin Co: New York, 1977.
9. Russell, Tony. Smithsonian Nature Guide: Trees. Dorling Kindersley: London, 2012.
10. Sibley, David Allen. The Sibley Guide to Trees. Alfred A. Knopf: New York, 2009.

Suppliers

1. Alpha Nurseries, Inc. – Holland, MI – (269) 857-7804 – info@alphanurseries.com
2. Chief River Nursery – Grafton, WI – (800) 367-9254 – info@chiefrivernursery.com
3. Cold Stream Farm – Free, Soil – (231) 464-5809 – info@coldstreamfarm.net
4. Kollar Nursery – Pylesville, MD – (410) 836-0500 – kollarnursery.com
5. Native Forest Nursery – Chatsworth, GA – (706) 483-3397 – nativeforestnursery.com