A showy Missouri native tree, the Shellbark Hickory, Carya laciniosa, creates a large canopy perfect for places that need shade. The tall, straight trunk features bark that peals away in large curly pieces, giving the tree its name. Male flowers of long catkins pollinate the short female flowers on the same tree. The female flowers give way to nuts encased in a green husk ripening in fall.
I. Appearance and Characteristics
Carya laciniosa, the shellbark hickory, in the Juglandaceae or walnut family is also called kingnut, big, bottom, thick, or western shellbark, attesting to some of its characteristics. It is a slow-growing, long-lived tree, hard to transplant because of its long taproot, and subject to insect damage. The nuts, largest of all hickory nuts, are sweet and edible. Wildlife and people harvest most of them; those remaining produce seedling trees readily. The wood is hard, heavy, strong, and very flexible, making it a favored wood for tool handles. A specimen tree has been reported in Missouri with 117 cm (46 in) diameter at breast height, 36.9 m (121 ft 1 in) tall, and a spread of 22.6 m (74 ft 2 in).
Shellbark hickory is widely distributed, but is nowhere common. The range extends from western New York through southern Michigan to southeast Iowa, south through eastern Kansas into northern Oklahoma, and eastward through Tennessee into Pennsylvania. This species is most prominent in the lower Ohio River region and south along the Mississippi River to central Arkansas. It is frequently found in the great river swamps of central Missouri and the Wabash River region in Indiana and Ohio. It’s also found scattered in the Hudson valley in New York state
In part due to the activities of humans, shellbark hickory has become rare in its natural range. The heavy seeds do not travel far from the parent tree and many stands have been lost to forest clearing and lumber harvesting. It is also not planted much as an ornamental due to its slow growth and difficulty of transplanting.
II. How to Grow and Care
Shellbark hickory requires a strategic approach to cultivation, given its size and growth habits. With a need for ample space, shellbark hickory thrives in well-draining soil and full sun conditions. Special care points include its sensitivity to transplanting and the necessity for patience, as shellbark hickory has a slow growth rate and may take years to mature fully.
Sunlight
Shellbark hickory plants are adaptable to grow in partial shade to full sun. However, it grows the best with full sunlight which means at least 8 hours of sunshine should be received.
Temperature
Native to North US, China and the rest of Asia, shellbark hickory grows in an annual temperature ranging between 4 to 18 ℃, with 27 ℃ in summer and -15 ℃ in winter. Extreme temperatures observed range from 46 ℃ to -40 ℃. Throughout the distribution of shellbark hickory, the mean annual rainfall ranges from 64 to 127 cm. During its peak growing season, rainfall ranges between 51 to 102 cm. Although it seems shellbark hickory loves moist, it is somehow drought-tolerant and cannot stand waterlogging.
Watering
Shellbark hickory thrives in its native environment where it has adapted to withstand periodic dry spells, indicative of a plant that appreciates some drought tolerance. Its water habits are balanced, requiring moisture without being waterlogged. For optimal health, shellbark hickory should be watered once every 1-2 weeks, aligning with its moderate need for hydration. Commonly grown outdoors due to its size and growth habit, shellbark hickory is particularly sensitive to overwatering during its dormancy time in colder seasons when the plant’s water uptake significantly decreases.
Soil
Shellbark hickory can grow on a variety of soil conditions including moist sandy, loamy and clay soils, from moderately acidic to alkaline. But they perform superbly in moist, rich, slightly acidic to neutral (pH 6.1-7.3), silty loam that is well-drained.
Fertilizing
Fertilize shellbark hickory with balanced nutrition fertilizers for overall health or high nitrogen fertilizers to stimulate early growth. Apply once annually in late winter or early spring, with quantity determined by tree size and soil test results. Avoid excesses, which may harm shellbark hickory. Seasonal changes influence nutrient uptake; less is needed during dormant periods. Apply at drip line, not near trunk, and water well to incorporate. Proper fertilization improves vigor, enhances nut production, and builds resilience.
Planting Instructions
You can start your shellbark hickory planting with either seeds or saplings. However, as shellbark hickory is a medium- to slow-growing tree, it is recommended to plant saplings bought from a nearby nursery or gardening store. The excellent growth of shellbark hickory is observed on raised beds with adequate moisture. You can make raised beds that fit the size of the root ball of the saplings for transplanting.
Prepare beds by digging deep earth up, loosening and mixing with the garden soil at a sunny location. Multiple trees should be spaced 6 to 7 m between the rows if grown in the orchards or as open field cultivation. What you should know is, none of the Carya species are suitable for containers due to their deep, straight root system. You can only grow shellbark hickory in your garden or orchard.
Pruning
Generally, pruning is not a necessity of shellbark hickory but light pruning throughout the year can improve the light reception of inner foliage. Trimming is favored for the newly grown plants as well, which promotes growth. Don’t mess the main truck, just remove weak, broken and dead twigs on the secondary branches when noticed.
Propagation
Shellbark hickory is a species known for its appealing, rugged appearance and valuable nuts. Propagation primarily involves sowing, where stratified seeds demonstrate the best germination rates. Seedlings require carefully prepared soil, rich in organic matter and well-draining, to thrive. Consistent moisture is essential, especially in the early stages of development. For successful growth, provide a site with ample sunlight and space, accounting for its future large stature. Protect young plants from wildlife predation to preserve the developing crop.
Transplanting
Optimum transplantation time for shellbark hickory aligns with the vernal rejuvenation period, ensuring strong root establishment. Choose sites with deep, fertile soils, offering ample sunlight. If relocation is necessary, prioritize minimal root disturbance to facilitate acclimatization.
III. Uses and Benefits
The seeds within shellbark hickory nuts are edible and consumed by ducks, quail, wild turkeys, squirrels, chipmunks, deer, foxes, raccoons, and white-footed mice. A few plantations of shellbark hickory have been established for nut production, but the nuts are difficult to crack, though the kernel is sweet. The wood is used for furniture, tool handles, sporting goods, veneer, fuelwood, charcoal, and drum sticks.
IV. Harvesting and Storage
Notice that only shellbark hickory trees older than 10 years start producing nuts. Harvest in fall when the brown, readily ripe nuts drop down on the ground. If the ripe nuts still stay on the tree, a gentle shake can promote free falls onto the ground. Pick the nuts from the ground before rodents and birds, remove the remaining husks and store the nuts with the outer shell where cool and dry if you are not eating them immediately. You can also crack the outer shell and store the meat of the nut by refrigerating or freezing.