Planting acorns, nuts and seed: collecting, storing and the first year

Sow a white-oak-group acorn the week it falls, because it puts down a root within days and keeps poorly. Red-oak-group acorns, most nuts and much of the small seed need a cold, damp winter before they sprout. Either sow them outdoors in fall and let the winter supply it, or hold them damp in the refrigerator, not the freezer, and sow in spring. The rest is sound seed, no drying for the kinds that die of it, a pot deep enough for a taproot, and hardware cloth against squirrels, mice and jays.

At Blue Whale Trees we offer most of the species we grow as acorns, nuts or seed as well as saplings. All of them are collected from the same proven parent trees as our saplings and listed under acorns, nuts and seed. The choice for each main group runs like this, and the sowing planner gives the dates for any species we grow:

Collecting sound acorns and nuts

Acorns picked off the tree are immature and may never sprout, and the first to fall are often the poorest of the crop.

“Ignore the first acorns that fall because they are often damaged or of poor quality.” (Mississippi State University Extension, Growing Your Own Oak Seedlings)

Gather once most of the acorns are coming down, and soon after. Acorns begin to dry the moment they land. In hot, dry weather three or four days on the ground can kill them, or a week for chestnuts. Carry them in a bucket or a breathable sack rather than a plastic bag, and keep them cool and shaded.

Sort them next: discard any acorn still holding its cap, since a ripe one slips easily out of its cup, overcup oak excepted. Also discard any with rot, mold or a small hole. The hole usually means an acorn weevil. Weevils and other acorn insects take a bigger share of a light crop than of a heavy one, and none spreads to sound acorns in storage.

Water makes the last cut: sound acorns sink, and a floater has an undeveloped embryo or other damage. After dry weather some good acorns float until they have soaked overnight, and after rain some bad ones sink until they have dried for a few hours. Overcup acorns float even when sound, and the same test sorts husked walnuts and chestnuts.

White oaks sprout at once, red oaks wait for spring

The oaks we sell as acorns fall into the two groups set out in red oaks and white oaks, most of them among our rare and uncommon oaks, and the group sets the calendar. White-group acorns have little or no dormancy.

“White oak acorns do not exhibit dormancy […] Under natural conditions, acorns begin germinating soon after they fall” (USDA Forest Service, Fire Effects Information System, Quercus alba)

White oak sends its root down in fall and holds the shoot back until spring, which keeps the shoot from freezing, and a root snapped in handling grows back. Our white-group acorns belong in the ground in fall, because white-group acorns sprout in storage and keep worse than red-group acorns. Overcup oak is the white oak that waits: its acorns stay dormant over winter and germinate in spring after the floodwaters recede, one of the ways floodplain trees survive high water.

Red-group acorns carry a dormancy that cold, damp weeks release, so a fall sowing needs nothing more, and weeks in a refrigerator used for storage count as the chilling. Some sprout in the bag, and a sprouted acorn can still be sown. Ours include cherrybark oak and bear oak, a red oak in which white oak’s pause between root and shoot has been reported.

Eight of them, by group and by when to sow them:

Hickories, walnuts, chestnuts and hazelnuts

Most nuts have a dormant embryo, and dormancy is how a seed waits for better conditions, which for a nut that falls in October means spring. Weeks of cold, damp conditions release it, in the ground or in a refrigerator, and nurseries call the treatment stratification.

Hickory nuts, from shagbark to the northern pecan, should soak for two to four days before their cold months. During the soak, change the water once or twice a day. Shagbark’s dormancy lifts after 90 to 120 days. Pecans from southern sources are nearly free of dormancy, and northern ones need the cold. Hickory nuts and walnuts survive drying, which acorns do not, so dormancy, not moisture, sets their calendar.

Black walnut can go in husked in fall, but in the Northeast stratified nuts sown in spring came up at more than twice the rate of unstratified nuts sown in fall. Husking does not stop rodents, as was once claimed; a screen does.

Chestnuts, like acorns, die if they dry. Float Chinese chestnuts as soon as they are gathered, soak overnight any picked up dry, and store them at 34 to 37 degrees in a bag that is not airtight. Allegheny chinquapin can sprout on the tree in a wet fall, so it goes in the ground as soon as it drops. American hazelnut should stay damp too, because drying deepens its dormancy.

Small seed: hard coats, two winters and pawpaw

In the wild, American persimmon seed usually comes up in April or May, but some waits two or three years, held back by a covering that caps the root. Unlike pawpaw, persimmon seed can be dried and stored.

Pawpaw seed must never dry out or freeze, because either can kill the dormant embryo.

“If seeds are dried for 3 days at room temperature, the germination percentage can drop to less than 20%.” (Kentucky State University, Pawpaw Planting Guide)

In a 1998 Kentucky study, pawpaw seed lost half its viability drying from 37 percent moisture to 25, and only about one seed in eight sprouted without chilling. Keep it in the refrigerator in a bag with a little damp sphagnum moss, or sow it outdoors in fall and expect it to germinate the next summer, in late July or August. Cucumber magnolia and sweetbay magnolia seed must also be kept moist to stay alive.

Eastern redbud has two locks, a coat that water cannot get through and an embryo that wants cold. Dip the seed in boiling water for 15 seconds and soak it for a day, or leave it overnight in water poured at about 190 degrees, then chill it or sow it in fall. Black locust has the coat alone, so hot water is all it needs, and a home grower files through the thick coat of Kentucky coffeetree.

The slowest seed has two dormancies: a warm spell grows the root and a winter releases the shoot, so in the wild the seedling appears the second spring after the seed falls. White fringetree, witch hazel, gray dogwood and Carolina silverbell all work this way to some degree; sow them outdoors in fall as soon as they are cleaned and leave the bed alone for two springs. Stored seed of northern arrowwood viburnum goes in the ground in spring, to get its summer before its winter.

Storing seed, and where to sow it

Store seed in a plastic bag with the top folded over, not sealed, because damp seed breathes fast enough to use up the oxygen in a closed bag within weeks. A little peat, sand or sphagnum, soaked and squeezed until no water runs, keeps it damp. Keep the bag at 34 to 40 degrees in the refrigerator, never the freezer, since storage below about 23 degrees usually kills acorns, and every two or three weeks pick out anything moldy or soft. The sowing planner counts the weeks for each species and says when to check the bag and when to plant.

Where to sow comes down to the taproot. A white oak seedling ends its first year three or four inches tall over a taproot more than a foot long, and black walnut taproots have gone down more than four feet in a year. A shallow seed tray has no room for that: the root reaches the bottom and turns, and circling roots are how a tree ends up strangling itself.

So sow a taprooted seed where the tree will grow, in a nursery bed, or in a pot. The pot should be at least a foot deep, with ribbed sides and an open bottom. Stand it off the ground so the root is air-pruned instead of circling. Pawpaw wants a tree pot 14 to 18 inches tall. A bed goes in full sun on well-drained ground, four to seven acorns to the square foot, and a fall-sown bed gets a mulch against frost heaving that comes off as the seedlings emerge.

Pin a lid of hardware cloth over every bed and pot until the seedlings are up. The lid is needed because squirrels dig acorns, blue jays and grackles raid nursery beds, and mice and other rodents eat them. The mesh sizes and the cages that come next are in protecting young trees from animals.

The first year and the first move

Oak and most nut seedlings want the whole stem in full sun, water at least weekly when rain is irregular, and no weeds, which otherwise slow or kill them. Pawpaw is the exception, because full sun can kill a germinating pawpaw; shade it through its first summer and sometimes its second.

A foot-deep pot holds a seedling for one season, and most go out at the end of it. Forestry nurseries plant oaks as one-year seedlings, and pawpaw seedlings are usually sold at one. The Forest Service advises field-planting persimmon, with its strong taproot, at the end of its first season. Keep pots on a bench, because roots grow from a pot on bare soil into the ground and tear when it is lifted. Kept a second year, a seedling needs a bigger pot and its circling roots straightened or cut at planting.

Move it while dormant, after several frosts have hardened it off. Pawpaw, with fleshy, brittle roots, moves best in spring as growth starts. Taprooted oaks also move better in early spring than in fall, as transplanting young trees explains. Dig deep, since a bed-grown seedling’s root runs deeper than its top is tall, set the root flare at the soil line, and cage it the same day, as for a bare-root tree on arrival.

Then comes the wait, longer above ground than below. A shagbark hickory in the Ohio Valley stood under eight inches tall at three years, over a taproot 2.6 feet deep. A persimmon is about eight inches after its first year. A redbud can make 6 to 12 inches in a nursery season and flower at three or four years. A pawpaw grows slowly for two years, then faster, fruiting at about six feet in five to eight years. After that the slower oaks may make 20 feet in 10 to 12 years and the faster ones 30 to 40, and the growth estimator gives the range for each of our species by site.

Common questions

Can you plant acorns in the fall?

Yes: white-oak acorns root within days and go in the week they fall, and red-oak acorns sown in fall get their winter in the ground and come up in spring.

Can you store acorns in the freezer?

No, because storage below about 23 degrees usually kills them; keep them in a loosely closed bag in the refrigerator at 34 to 40 degrees.

How long does it take to grow an oak from an acorn?

A white oak ends its first year three or four inches tall over a foot of taproot, ready to plant out, and a slow oak may then make 20 feet in 10 to 12 years.

Sources

• Quercus L., oak: USDA Forest Service, Woody Plant Seed Manual, Agriculture Handbook 727 (F.T. Bonner, 2008): the signs of a ripe acorn, flotation and its two traps, insect damage in light crop years, storage in loosely closed bags and the lethal cold below minus 5 degrees Celsius, the dormancy of each oak group, bear oak’s delayed shoot, sowing depth, one-year planting stock, and the jays and grackles that dig up seedbeds.
• Woody Plant Seed Manual, genus chapters: USDA Forest Service, Agriculture Handbook 727 (2008): the Carya, Juglans, Castanea, Corylus, Diospyros, Magnolia, Cercis, Robinia, Gymnocladus, Chionanthus, Hamamelis, Cornus, Halesia, Viburnum and Prunus chapters, for stratification periods, tolerance of drying, seed coat treatments, double dormancy, sowing depths and when persimmon seedlings are planted out.
• Silvics of North America, Volume 2: Hardwoods: USDA Forest Service, Agriculture Handbook 654 (1990): white oak’s root-first germination and first-year taproot, the first-year and third-year growth of shagbark hickory and its stratification period, the first-year height of persimmon and the first-year taproot of black walnut.
• Quercus alba, Fire Effects Information System: USDA Forest Service: white oak acorns without dormancy, germinating soon after they fall.
• Quercus lyrata, Fire Effects Information System: USDA Forest Service: overcup oak’s buoyant acorn, its dormancy over winter and its germination in spring.
• Growing Your Own Oak Seedlings: Mississippi State University Extension (Self, Rousseau and Beliech, 2024): skipping the first acorns to fall, sorting and floating, refrigerated storage and mold checks, seedbed spacing, pots a foot deep with open bottoms, first-season light and water, lifting after frost, and oak growth over ten to twelve years.
• Pawpaw Planting Guide: Kentucky State University: keeping pawpaw seed from drying or freezing, 70 to 100 days of stratification, tall containers for the taproot, shade for young seedlings, spring transplanting, the age of nursery seedlings and the years to first fruit.
• Requirements for seed germination in North American pawpaw: Finneseth, Layne and Geneve, Seed Science and Technology 26 (1998), abstract at the University of Kentucky: the 12 percent of seed that germinates without chilling and the viability lost as the seed dries.
• Acorn and Nut Collection Guide: Virginia Department of Forestry (2026): breathable bags, cool storage and no freezer for collected acorns and nuts.