Shagbark Hickory

From the second season onward (not at planting): measure the trunk diameter 5 inches above the ground. Spread 1 lb of 10-10-10 per inch of trunk diameter under the outer edge of the canopy, never more than 1/3 lb of actual nitrogen per inch of trunk diameter per season. Time it to the last few weeks of dormancy, before budbreak - late February in Kentucky and the mid-South, March where winters run longer. Do not broadcast onto frozen or snow-covered ground; the fertilizer will run off with snowmelt before roots can take it up. Soil test yearly and lime as needed so the pH never drops below 6.0. Trunk diameter is the honest proxy for how much root and canopy there is to feed, and fertilizer placed at the canopy periphery lands over the feeder roots rather than the trunk. Applying just before budbreak puts the nitrogen there when the tree starts pulling on it.

Prune young trees lightly in late winter to pick out scaffold limbs with wide crotch angles and keep a single central leader. Clear the branches off the trunk to a height of at least 6 feet if you plan to band it with a metal squirrel guard. Once 10 to 15 well-spaced scaffolds have formed, cut the leader back to a lateral and let the tree run as a modified central leader. Bearing trees need very little: take dead limbs back to a side limb or the trunk. Wide crotch angles and a single leader are what keep a 70-foot tree from splitting at a fork decades later, and cuts made while the tree is dormant and leafless heal before the borers and bark beetles fly.

Just after pollination, spray the foliage with zinc sulfate at 1 to 2 lb per 100 gallons (1 to 2 tablespoons per gallon) on young trees, or 5 to 10 lb per 100 gallons on mature trees. Repeat twice more at two to three week intervals. For soil application use zinc chelate instead of zinc sulfate. Zinc is the trace element nut trees run short of first, and when it is lacking the nutlets simply fail to set - the crop is lost at the very beginning rather than late.

Irrigate through summer dry spells on bearing trees. Water matters at two moments: before the shells form, and again after the shells harden. Newly planted trees need watering weekly through their first summer. Water scarcity before the shells form caps how big the nut can ever get, because the shell sets the envelope the kernel must later fill, and drought after shell hardening leaves you full-sized nuts with shrivelled kernels rattling inside.

Starting as the kernels begin to harden, spread a large sheet under the tree once a week and jar the limbs with a padded pole. Count the brown, long-snouted weevils that drop. Three or more out of one tree is the threshold to begin spraying. Weevils usually emerge after the first good rain once kernels harden. If you would rather not spray, shaking them onto the sheet and destroying them week after week genuinely reduces the damage. The female drills the shell and lays inside the nut; once the egg is in there the grub is sealed away from any spray, so the only window that exists is the days between her emerging from the soil and her laying.

Only if your jarring counts hit three weevils per tree, or the tree has a weevil history, spray carbaryl (Sevin) on the lower 8 feet of the trunk starting at shell hardening. Repeat for two to four applications at 7 to 10 day intervals. Do not apply after shuck split. Stop at least 14 days before you expect to harvest. Bifenthrin is the other labelled option. Weevils walk up the trunk after emerging from the soil, so a band on the lower trunk intercepts the females on their way to the nuts - the one place and time they are exposed. Once she has drilled the shell and laid inside the nut, no spray reaches the grub.

Bolt a 4-foot-wide tin or aluminum shield around the trunk with its lower edge at least 4 feet off the ground, four to six weeks before you expect squirrel damage. Fit it before the nuts ripen, not after the raids start. The shield works by denying squirrels any purchase on the trunk, so it has to be up before they establish the tree as a food source rather than in response to losses.

Gather hickory nuts as soon as they fall - do not let them lie. Hull them and spread the nuts on screens to dry. Crack a couple every few days to test; when the kernels are crisp, store the nuts in their shells in mesh bags somewhere cool, well ventilated, and out of reach of squirrels. Nuts left on wet ground pick up mold and off flavors, and the drying is what converts the kernel to storage condition - a nut bagged before its kernel goes crisp will mold in the bag.