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A Forager’s Year

No. 71

Hickory

Carya tomentosa, C. glabra, C. ovata

mockernut, pignut, shagbark

Nut & seed nuts

Drawing: Britton & Brown, Illustrated Flora (1913)

Find
Common in the right habitat
Effort
Real work
ID risk
Beginner
Origin
native
Uses
  • Eat raw / salad
  • Baking & desserts
  • Nut milk & oil
  • Roasted nuts

Season

  1. Jan
  2. Feb
  3. Mar
  4. Apr
  5. May
  6. Jun
  7. Jul
  8. Aug
  9. Sep
  10. Oct
  11. Nov
  12. Dec

in season peak

What these mean

Find

1 Everywhere · 2 Common in the right habitat · 3 Patchy · 4 Elusive. This is about how much there is, not whether you may pick it. It is based on iNaturalist sightings within 25 km (about 15 miles) of downtown DC, counted on October 3, 2026. The four rules that each plant’s “Find” reason refers to: (A) the estimate is the confirmed sightings, plus the unconfirmed ones (scaled down where the plant has lookalikes in its genus), plus the sightings marked as planted; (B) the tier by estimate: 1,500 or more is tier 1, 250–1,499 tier 2, 50–249 tier 3, under 50 tier 4; (C) tier 1, Everywhere, also needs a source saying the plant is common in lawns, sidewalks, yards or gardens, vacant lots or towns, or at least one DC street tree of it per km of sidewalk, otherwise it is tier 2; (D) if a reliable source says the plant is rare in this region, or that wild plants rarely bear the harvest, only planted sightings count. iNaturalist is a website and phone app where people post photos of the plants and animals they see. A sighting is “research grade” when other users have confirmed what it is; “needs ID” sightings are not confirmed yet, and “cultivated” ones are marked as planted.

Effort

1 Grab & eat · 2 Quick kitchen prep (under about 30 minutes) · 3 Real work (hours, or cooking needed for safety) · 4 Project (days or equipment). Scored on the simplest worthwhile use; each plant’s page says why.

ID risk

How hard it is to harvest safely. Beginner: no dangerous lookalike, and the edible part is not easily confused with a toxic part. Careful: a toxic lookalike, or toxic parts that end up in the harvest unless removed (for example elderberry stems, unripe ground cherries), or other parts of the plant rated medium-or-higher toxicity, with reliable features to separate them. Expert only: a potentially deadly lookalike that is hard to separate, or (for not-recommended harvests like pokeweed) a plant whose safe preparation can’t be guaranteed. Toxic parts that are obviously separate and thrown away anyway (pits, seeds, skins) don’t raise it; the Toxic parts mark carries that warning.

Native or not, and the invader stars

Origin is where the plant comes from: native, non-native, or mixed (the harvest covers both). The stars rate plants on invasive plant lists: ★★★ Virginia DCR “High” or Maryland prohibited invasive · ★★ Virginia “Medium” · ★ Virginia “Low” · ☆ listed only by the Maryland Invasive Species Council or the Mid-Atlantic Plant Invaders guide (advisory) · no stars: native or not listed.

Seasons

Start, peak and end are given in thirds of a month: early, mid or late. A plant counts as in season for a month if it is in season at any point in that month. Some greens and roots have a second window, in spring or fall; their page shows each window. A season that runs across New Year is shown as one window.

What it looks like

Hickories are tall native trees with compound leaves. Each nut sits in a husk that turns from green to brown or blackish as it ripens. Mockernut and shagbark husks split to the base in four sections, releasing the nut; pignut’s husk splits only about halfway and tends to cling to the nut. Mockernut leaflets are often fuzzy underneath, and its nuts are notoriously hard to open. Shagbark is easy to recognize by its bark, which separates into long, shaggy strips that curve outward. Shagbark kernels are sweet; pignut kernels range from sweet to bitter, so taste one first.

Safety

Bitternut hickory (C. cordiformis) has intensely bitter, astringent, high-tannin kernels, and the Silvics Manual calls them unfit to eat. Identify trees before collecting. Pignut kernels range from sweet to bitter, so taste one first. Tree-nut allergy: FDA’s 2025 labeling guidance took hickory nut off its list of major tree-nut allergens for lack of strong evidence. That is a labeling decision, not proof the nut is safe for people with tree-nut allergies.

Lookalikes

  • Bitternut hickory Carya cordiformis harmless (may be edible)

    Bitternut is the hickory with sulfur-yellow, pointed buds. Its bark is granite-gray in an interwoven pattern, not shaggy; its leaves have 7 to 11 finely toothed leaflets; and its thin husk, in four ridged sections that come to a point, holds a thin-shelled nut the size of a nickel to a half dollar (Keystone Tree Crops Cooperative’s harvester’s handbook). Its kernels are intensely bitter and astringent (USDA’s Silvics Manual calls them unfit to eat); identify the tree and taste one kernel before collecting.

Safety flags

Safety marks and flags: what this means

Deadly lookalike / Toxic lookalike: a cited source names a lookalike of that danger. Deadly means a source says eating it may be fatal or calls it deadly, or NC State rates it high severity with life-threatening symptoms (sources sometimes disagree; for example Virginia creeper). Each plant’s Lookalikes list says how to tell them apart; “harmless (may be edible)” lookalikes are listed so you know a mix-up isn’t dangerous. Cook first: cooking is needed for safety (for daylilies it is a precaution, not a sourced requirement). Eat in moderation: a source says to limit quantity or frequency (for example oxalates in sorrels and dock, ginkgotoxin, safrole). Spray risk: a source says the plant is commonly treated with herbicide in parks or lawns (invasive control, lawn weeds) or, for ginkgo, sprayed to stop fruiting. Contamination: a source says the plant concentrates pollutants. Each plant’s Safety flags list gives the details and sources.

ID risk
Beginner
Why
No toxic lookalike. Bitternut hickory kernels are intensely bitter and unfit to eat but not described as dangerous; taste pignut kernels first.
Soil risk
low
ID risk: what this means

How hard it is to harvest safely. Beginner: no dangerous lookalike, and the edible part is not easily confused with a toxic part. Careful: a toxic lookalike, or toxic parts that end up in the harvest unless removed (for example elderberry stems, unripe ground cherries), or other parts of the plant rated medium-or-higher toxicity, with reliable features to separate them. Expert only: a potentially deadly lookalike that is hard to separate, or (for not-recommended harvests like pokeweed) a plant whose safe preparation can’t be guaranteed. Toxic parts that are obviously separate and thrown away anyway (pits, seeds, skins) don’t raise it; the Toxic parts mark carries that warning.

Soil risk: what this means

Based on the part you eat, following the urban-soil lead guidance on the Field safety page: higher for greens, shoots and roots; moderate for flowers; low for fruit, nuts and sap.

Field safety for every outing (poison ivy, ticks, soil, and more)

When to pick

Starts
mid Sep
Peak
early Oct–early Oct
Ends
early Dec

Hickory nuts ripen in September and October (USDA Forest Service Silvics Manual; Woody Plant Seed Manual). In southwest Virginia’s mountains, shagbark, mockernut and pignut ripen from mid to late September (Virginia DWR), and Penn State Extension suggests gathering hickories in October and November. Nuts keep falling into December (Silvics Manual), but squirrels start on them before they are ripe and keep eating until they are gone, so late pickings are thin. The early-October peak is an estimate. Crops are irregular: good shagbark crops come every 1-3 years with little in between (Silvics Manual), pignut every 1-2 years (Woody Plant Seed Manual), and mockernut crops vary a lot from year to year.

How the dates were worked out

Every start, peak and end was re-checked in October 2026. “Sourced” means a source opened during the check states that timing for the DC or Mid-Atlantic area. “Estimated” means no source states it exactly; the reason, the evidence and the source links are under “How the dates were worked out” on each plant’s page. Peaks are often estimated, because few sources name a peak. iNaturalist evidence means research-grade sightings near DC, by month, of the plant at that stage (for example, in fruit). iNaturalist is a website and phone app where people post photos of the plants and animals they see. A sighting is “research grade” when other users have confirmed what it is; “needs ID” sightings are not confirmed yet, and “cultivated” ones are marked as planted.

Season basis: estimated: peak, end

Start

sourced

Peak

estimated: No dated DC source; early October is the midpoint of the Sept-Oct ripening and dispersal window for the three species. iNat fruiting counts (all hickories, 3 each in Sep, Oct, Nov) are too sparse to show a peak.

End

estimated: Sources give dispersal into December range-wide but no third; early December matches the last DC iNaturalist record (Dec 10). Squirrels eat nuts until the supply is gone (Silvics), so December finds are few.

Evidence

start: Virginia DWR (Sept 2018, SW Virginia): black walnuts and shagbark, mockernut and pignut hickories ripen 'about this time', i.e. mid to late September. Silvics (shagbark, mockernut, bitternut) and the Woody Plant Seed Manual table give ripening September-October for all three DC species. | peak: Woody Plant Seed Manual: mockernut, pignut and shagbark ripen Sept-Oct and disperse Sept-Oct; Penn State Extension (Lehigh Co., PA) says hickories can be collected in October and November. | end: Silvics (shagbark, bitternut) and FEIS (pignut, shagbark): seed dispersed September through December. Penn State Extension: collect in October and November. The last DC iNaturalist fruiting record is Dec 10 (2025); the iNaturalist counts cover the whole hickory genus (the Dec 10 record is a pignut).

Where to look

Upland oak-hickory slopes; the C&O Canal allows a bushel a day, but many towpath hickories (13 of 16 logged at Carderock) are bitter bitternut, so check the species. Rock Creek Park, where mockernut, pignut and shagbark are logged most near DC, bans nut gathering.

Habitats
disturbed ground & waste places, old fields & meadows, floodplain & stream-valley forest, upland oak-hickory woods
Habitats: what this means

Listed where the plant’s own sources place it in that habitat. “Disturbed ground & waste places” means a cited source places it on disturbed areas, sites, soil or ground, on waste places or waste ground, on construction or abandoned building sites (old home sites count), on rubble or in strip mines. When the source gives examples of the disturbed places, at least one example must be of that kind. Examples that do not count: natural or forestry disturbance (treefall gaps, fire, windthrow, flood scour, old riverbanks and creeks, clear-cuts); roadsides, railroads and rights-of-way; and abandoned fields, pastures and farmland, which are “Old fields & meadows”. “Vacant lots” only where a source says vacant or empty lots.

Most-logged places

You may pick here

  • C&O Canal NHP (towpath, Georgetown to Great Falls MD and beyond)

    20 sightings · Legal to pick: yes · see them on iNaturalist

    Legal to pick under the C&O Canal compendium (by hand, personal use, daily limit; trail-side only at Great Falls MD). Of these, 3 are at Carderock.

No picking here (4 places)
  • Rock Creek Park

    22 sightings · Legal to pick: no · see them on iNaturalist

    Look but don’t pick: Rock Creek Park’s compendium bans gathering any fruit, nut, berry, seed or greenery.

  • Huntley Meadows Park

    14 sightings · Legal to pick: no · see them on iNaturalist

    Look but don’t pick: Fairfax County parks ban removing any plant part without written permission.

  • Four Mile Run stream valley (Arlington/Alexandria)

    11 sightings · Legal to pick: no · see them on iNaturalist

    Look but don’t pick: Arlington County park rules (flora shall not be removed or disturbed) and Alexandria’s permit rule both apply.

  • Glencarlyn Park

    11 sightings · Legal to pick: no · see them on iNaturalist

    Look but don’t pick: Arlington County park rules say flora shall not be removed or disturbed.

Most-logged places: what this means

The places with the most research-grade iNaturalist sightings within 25 km of downtown DC (re-counted in October 2026 over every named place, campuses, condominiums and private grounds included), each marked legal to pick or not. A sighting inside several named places counts once, for the smallest of them, but a sighting inside a National Park Service park never counts for a private, campus or unchecked place. iNaturalist shows where people walk and log plants, not true abundance. Private campuses, condominiums, museums, estates and utility land (Pepco’s power-line land near Sligo Creek) are marked “no” (pick only with the owner’s permission); public university campuses, city parks and other places whose picking rules were not checked (county stormwater land, the U.S. Capitol Grounds, Greenbelt’s North Woods, federal facilities such as the National Zoo) are “unknown”. A place needs at least 2 sightings, so plants with very few sightings (rugosa rose) have no places. No most-logged places are named for at-risk plants (ramps, chinquapin, American chestnut); chinquapin’s page names Mason Neck State Park, where picking is legal, and asks you to leave most nuts. For some places, mostly Rock Creek Park, the iNaturalist map shows more sightings than the count here, because a map link cannot leave out exactly the sightings credited to another place. iNaturalist is a website and phone app where people post photos of the plants and animals they see. A sighting is “research grade” when other users have confirmed what it is; “needs ID” sightings are not confirmed yet, and “cultivated” ones are marked as planted.

Ways to use it

  • Crack in a vise and pick out the meats. This is slow work: about 3 hours yields roughly 1.5 cups (Farm and Dairy)
  • Roast lightly to bring out the flavor, then use in granola, cookies, fudge or hickory-nut cake (Farm and Dairy)
  • Bake into quick breads, cookies and a pie made like pecan pie, or scatter on salads, soups and pilafs (Missouri Dept. of Conservation)
  • Hickory-nut milk: pound the nuts, boil and strain them for a creamy liquid used in cooking (Missouri Dept. of Conservation)
  • Pawcohiccora: Powhatan people of coastal Virginia made 'pawcohiscora' (hickory milk, per John Smith) by grinding the nuts and steeping them in water (Historic Jamestowne)
  • Boil pounded nutmeats slowly and skim off the oil to use like butter (NativeTech)
  • Press for oil (Keystone Tree Crops Cooperative, which presses bitternut hickory): nuts are cured, dehusked, cracked and expeller-pressed, and the bitter tannins stay out of the oil. Raw nuts give a clean, neutral cooking oil, lightly roasted nuts a warmer finishing oil, with a smoke point around 450 F. Refrigerate after opening. Bitternut harvest runs from mid-September to early November, sometimes into December where squirrels and other wildlife leave the nuts; nuts on the ground in August are usually aborted, from weevils or other causes, and hold little or no kernel. Crack 10 to 20 nuts under each new tree to check their quality, and store nuts where air moves: in sealed buckets the husks mold within 1 to 2 weeks (KTCC harvester’s handbook).

Keeping

Dry them in the shell after gathering and store them cool in closed containers for months; freeze the picked-out meats.

Use within
months+
Keeps fresh
In shell, cool and dry: several months at room temperature once dried (WSU), and up to about a year refrigerated or 2 years frozen at 0°F (general guidance for nuts, OSU). Shelled nutmeats: several months refrigerated in a tightly closed container, 1-2 months at room temperature (WSU). A forager source reports in-shell hickories keep years cool and dry (Farm and Dairy).
Keeping basis
general guidance for its type

Ways to keep it

  • Dry as researched: roast & store; canning: n/a (not shelf-canned)

    Roasted nuts do not store as long as raw ones; use them within a few months (OSU).

  • Freeze as researched: freeze; canning: n/a (not shelf-canned)

    Freeze the shelled meats in airtight bags (WSU; Farm and Dairy).

  • Store whole as researched: store in shell; canning: n/a (not shelf-canned)

    Dry the nuts, then keep them in closed containers so Indian meal moths cannot get in, at 55°F or cooler, or refrigerate (OSU).

Canning: what this means

Shelf-stable canning, three levels. Lab-tested: a lab-tested recipe from the National Center for Home Food Preservation (NCHFP) or Oregon State covers this fruit and product, or a generic recipe for its kind (the line says so, for example chokeberry). Extension recipe: a published Extension recipe (University of Alaska Fairbanks, written for Alaska species; University of Maine’s dandelion jelly), or a process that is safe only with a pH meter; follow it exactly, never improvise. No tested recipe: refrigerate or freeze, don’t can. “Hot-bottled syrup” = maple and walnut syrup, which keep when bottled hot at full syrup density. The Canning line names the exact product each source covers, for example “whole berries” or “juice”; a product not named there (such as juice from a berry with only a whole-berry recipe) has no tested recipe.

Keeping basis: what this means

“Specific to this plant” or “general guidance for its type” (for example NCHFP guidance for leafy greens applied to a wild green).

Nutrition

Not researched: in October 2026, only the calendar’s plants of the month and chicory leaves were researched.

Native or not

Origin
native
Native range
eastern North America
Virginia invasive rank
not listed
Maryland invasive status
not listed
Native or not, and the invader stars: what this means

Origin is where the plant comes from: native, non-native, or mixed (the harvest covers both). The stars rate plants on invasive plant lists: ★★★ Virginia DCR “High” or Maryland prohibited invasive · ★★ Virginia “Medium” · ★ Virginia “Low” · ☆ listed only by the Maryland Invasive Species Council or the Mid-Atlantic Plant Invaders guide (advisory) · no stars: native or not listed.

Virginia DCR, Virginia Invasive Plant Species List (effective September 2024), verbatim: "Under the DCR Invasive Species Assessment Protocol, approved by the Virginia Invasive Species Working Group, January 2024, species were ranked as exhibiting high, medium or low levels of invasiveness based on their threat to natural communities and native species. Invasiveness rank is higher for species that: • Alter ecosystem processes, such as succession, hydrology or fire regime. • Are capable of invading undisturbed natural communities. • Cause substantial impacts on rare or vulnerable species or natural communities or high-quality examples of more common communities. • Are found widely distributed and generally abundant where present. • Disperse readily to new areas. • Are difficult to control." The list also states: "The list is for educational purposes only and has no regulatory authority."

Maryland Department of Agriculture, Maryland Prohibited Invasive Plant Law and Regulations page, verbatim: "Plants on the Maryland Prohibited Invasive Plant List may not be added to stock after the effective date and should not be sold after their phase-out period ends."

No official DC invasive plant list was found.

How the ratings were set

Find
Common in the right habitat Estimate 903 = 306 research-grade iNaturalist sightings within 25 km + 1,308 needs-ID sightings counted at 43% (in the October 5 genus count, 306 of the 713 research-grade Carya sightings here were mockernut, pignut or shagbark hickory) + 36 'cultivated' (planted) sightings (rule A); that is tier 2 by count (rule B). Only mockernut, pignut and shagbark are counted; bitternut hickory (387 research-grade sightings, the most-logged hickory here) is left out because its kernels are too bitter to eat (NativeTech), though its oil is pressed commercially. Final tier 2.
Effort
Real work Crack the hard shells in a vise and pick out the meats, slow work (about 3 hours for 1.5 cups); hickory milk is extra and pressing oil is a 4.
Find: what this means

1 Everywhere · 2 Common in the right habitat · 3 Patchy · 4 Elusive. This is about how much there is, not whether you may pick it. It is based on iNaturalist sightings within 25 km (about 15 miles) of downtown DC, counted on October 3, 2026. The four rules that each plant’s “Find” reason refers to: (A) the estimate is the confirmed sightings, plus the unconfirmed ones (scaled down where the plant has lookalikes in its genus), plus the sightings marked as planted; (B) the tier by estimate: 1,500 or more is tier 1, 250–1,499 tier 2, 50–249 tier 3, under 50 tier 4; (C) tier 1, Everywhere, also needs a source saying the plant is common in lawns, sidewalks, yards or gardens, vacant lots or towns, or at least one DC street tree of it per km of sidewalk, otherwise it is tier 2; (D) if a reliable source says the plant is rare in this region, or that wild plants rarely bear the harvest, only planted sightings count. iNaturalist is a website and phone app where people post photos of the plants and animals they see. A sighting is “research grade” when other users have confirmed what it is; “needs ID” sightings are not confirmed yet, and “cultivated” ones are marked as planted.

Effort: what this means

1 Grab & eat · 2 Quick kitchen prep (under about 30 minutes) · 3 Real work (hours, or cooking needed for safety) · 4 Project (days or equipment). Scored on the simplest worthwhile use; each plant’s page says why.

Sources

35 sources, each linked to the original.

  1. Rock Creek Park Superintendent’s Compendium (2026) National Park ServiceBacks up: picking rules
  2. 36 CFR 2.1 - Preservation of natural, cultural and archeological resources Legal Information Institute, Cornell Law School (text of federal regulation)Backs up: picking rules
  3. Maryland man fined $50 for picking berries ReasonBacks up: picking rules
  4. C&O Canal NHP Superintendent’s Compendium, effective September 11, 2026 National Park Service, Chesapeake and Ohio Canal NHPBacks up: picking rules
  5. 4VAC5-30-50. Flowers, plants, minerals, etc. Virginia Law Library (law.lis.virginia.gov)Backs up: picking rules
  6. iNaturalist research-grade observations of Carya tomentosa + C. glabra + C. ovata within 25 km of downtown DC iNaturalistBacks up: findability
  7. Carya tomentosa (mockernut hickory) Master Gardeners of Northern VirginiaBacks up: habitat, description
  8. Carya ovata (shagbark hickory) Master Gardeners of Northern VirginiaBacks up: habitat, description
  9. Harvesting, Handling, and Storing Nuts from the Home Orchard (FS 146, rev. 2013) Oregon State University Extension Service (PDF hosted by UC ANR)Backs up: keeping
  10. Food Safety and Preservation: Nuts & Seeds Washington State University Extension, Lewis CountyBacks up: keeping
  11. USDA PLANTS Database: Carya tomentosa (CATO6), native status USDA NRCSBacks up: native or invasive status
  12. USDA PLANTS Database: Carya glabra (CAGL8), native status USDA NRCSBacks up: native or invasive status
  13. USDA PLANTS Database: Carya ovata (CAOV2), native status USDA NRCSBacks up: native or invasive status
  14. Virginia Invasive Plant Species List (effective date: September 2024) Virginia Department of Conservation and Recreation, Division of Natural HeritageBacks up: native or invasive status
  15. Maryland Prohibited Invasive Plant Law and Regulations (Maryland Prohibited Invasive Plant List, updated January 2026; additions effective July 15, 2026; 'Next Plants To Be Assessed' 2026-2027) Maryland Department of Agriculture, Plant Protection & Weed ManagementBacks up: native or invasive status
  16. Non-Native Invasive Terrestrial Plant Species in the State of Maryland (updates approved through the April 18, 2024 MISC meeting) Maryland Invasive Species CouncilBacks up: native or invasive status
  17. Plant Invaders of Mid-Atlantic Natural Areas, Field Guide (Swearingen & Fulton, 2022; successor to the NPS/USFWS 5th ed., 2017) Mid-Atlantic Invasive Plant Council / Passiflora Press (hosted by Bugwood/Mid-Atlantic Invaders Tool)Backs up: native or invasive status
  18. Invasive Plants in the District DC Department of Energy & EnvironmentBacks up: native or invasive status
  19. FDA finalizes two guidance documents related to food allergens (Jan 2025) Covington & Burling LLP (summary of FDA guidance)Backs up: safety
  20. Carya cordiformis (Bitternut Hickory) NC State Extension Gardener Plant ToolboxBacks up: safety details
  21. Bitternut hickory (Silvics of North America) USDA Forest ServiceBacks up: safety, season
  22. Free Fall Food for the Asking: Locavore Living (Bruce Ingram, Sept 2018) Virginia Department of Wildlife ResourcesBacks up: season
  23. Growing Green: native nut tree species to be enjoyed (Sept 2024) Penn State Extension, Lehigh County (column in Lehigh Valley Press)Backs up: season
  24. Hickories (genus Carya) research-grade observations within 25 km of DC, by month (fruiting annotation) iNaturalistBacks up: season
  25. Mockernut hickory (Silvics of North America) USDA Forest ServiceBacks up: season, description
  26. Carya, hickory (Woody Plant Seed Manual, Agriculture Handbook 727) USDA Forest ServiceBacks up: season, description
  27. Shagbark hickory (Silvics of North America) USDA Forest ServiceBacks up: season, description, habitat
  28. Carya ovata (Fire Effects Information System) USDA Forest ServiceBacks up: season, description, habitat
  29. Carya glabra (Fire Effects Information System) USDA Forest ServiceBacks up: season, description, safety, habitat
  30. Hickory oil Keystone Tree Crops Cooperative (KTCC)Backs up: uses
  31. Assortment of whole hickory nuts Jamestown Rediscovery Foundation (Historic Jamestowne)Backs up: uses
  32. Shagbark hickory (field guide) Missouri Department of ConservationBacks up: uses, description, season
  33. Hickory (plant gathering) NativeTech: Native American Technology and ArtBacks up: uses, safety
  34. Yellowbud Hickory Harvester’s Handbook Keystone Tree Crops Cooperative (KTCC)Backs up: uses, safety
  35. Mother Nature’s best-kept secret: Hickory nuts Farm and DairyBacks up: uses, keeping