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A Forager’s Year

No. 68

Allegheny chinquapin

Castanea pumila

chinkapin

Nut & seed nuts

Drawing: Britton & Brown, Illustrated Flora (1913)

Find
Patchy
Effort
Quick kitchen prep
ID risk
Careful
Origin
native
Safety marks
  • Deadly lookalike
Uses
  • 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.

Safety marks and flags

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.

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

A thicket-forming native shrub or small tree, 15-30 feet, in the chestnut genus. Its leaves are pale and fuzzy underneath. Each small spiny bur, 3/4 to 1.5 inches, holds a single shiny brown nut. The nuts are sweet, and FEIS reports them often judged tastier than American chestnut.

Safety

Toxic lookalike: horse chestnut (Aesculus hippocastanum, often planted) and the buckeyes (Aesculus) are highly poisonous. NC State lists aesculin and aescin, with vomiting, paralysis and stupor, and says they may be fatal. Tell them apart by the leaves. True chestnuts have simple, toothed leaves set one at a time along the twig. Aesculus has palmately compound leaves with 5-7 leaflets radiating from one point. A true chestnut’s bur is densely covered in sharp bristles. A horse chestnut’s is a leathery capsule with sparse spines, smooth between them. Nut count is not reliable because sources disagree. One nut per bur is typical of chinquapin. True chestnuts usually have 2-3.

Lookalikes

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
Careful
Why
Same poisonous lookalike as chestnuts (horse chestnut and buckeyes): check for simple toothed leaves and a densely bristled bur. Chinquapin burs typically hold one nut, true chestnuts 2-3.
Handling hazards
Spiny husks (minor)
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.

Handling hazards: what this means

Stings, thorns, irritating or phototoxic sap, staining hulls and spiny husks, with a severity: minor = brief discomfort; moderate = rash or blisters lasting days; serious = burns, scarring or medical care possible.

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
early Sep
Peak
early Oct–early Oct
Ends
late Nov

Chinquapin nuts mature from September to November (Virginia DOF; FEIS). NC State Extension and USDA NRCS say the fruits mature in autumn and winter, and some burs stay on the tree through winter (Woody Plant Seed Manual), but squirrels and jays compete hard, so collect as soon as the burs split. The early-October peak is an estimate.

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

Start

sourced

Peak

estimated: No source gives a peak; early October is the midpoint of the September-November window.

End

sourced

Evidence

start: Virginia DOF identification guide: Alleghany chinkapin matures in its first year, September to November. FEIS: ripened nuts are available from September through November. | peak: Virginia DOF and FEIS: September to November. DC iNat fruiting records: one each in weeks 34, 37 and 42. | end: Virginia DOF: matures September to November. FEIS: nuts available through November. NC State and USDA NRCS say fruits mature in autumn and winter, and the Woody Plant Seed Manual notes some burs stay on the tree through winter.

Where to look

Dry, sandy or rocky acidic oak-pine woods and power-line clearings. Mason Neck State Park (14 research-grade sightings) is the one listed place with sightings where picking is legal (Leesylvania State Park is equally legal), but the tree is declining from blight and listed as threatened in some states, so leave most nuts for regeneration; other specific spots are withheld.

Habitats
old fields & meadows, woods edges, trailsides & thickets, 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.

Ways to use it

  • Eat like a small chestnut; the nuts were historically bartered and sold (FEIS; USDA NRCS)
  • Store and cook like other chestnuts: refrigerate fresh nuts, score before roasting (Oregon State Extension, written for chestnuts)

Keeping

Refrigerate or freeze the nuts within a day or two of gathering, as for chestnuts.

Use within
within a few days
Keeps fresh
Handle like a small chestnut: refrigerate fresh nuts soon after gathering, about 2 months in the shell in the fridge; they mold within about 2 weeks at room temperature (general guidance for chestnuts, OSU; Missouri).
Keeping basis
general guidance for its type

Ways to keep it

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

    Score before roasting, as for chestnuts (OSU).

  • Dry as researched: dry/dehydrate; canning: n/a (not shelf-canned)

    Dry rock-hard for flour, as for chestnuts (OSU).

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

    Freeze raw in a sealed bag; about 1 year at 0°F (general guidance for chestnuts).

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 & southeastern United States
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
Patchy Estimate 102 = 90 research-grade iNaturalist sightings within 25 km + 29 needs-ID sightings counted at 31% (90 of the 294 research-grade Castanea sightings here are Allegheny chinquapin) + 3 'cultivated' (planted) sightings (rule A); that is tier 3 by count (rule B). Rule D does not apply: USDA NRCS’s plant guide says "Chinkapin is rare in its range", but that is about its whole range, not this region, and the Digital Atlas of the Virginia Flora, a source of equal standing about Virginia, calls it "Frequent throughout". The National Park Service’s species lists mark it rare in Rock Creek Park and Fort Circle Parks, but a single park’s list is not a statement about the region, and the same lists call it common in Greenbelt Park, also inside the 25 km circle. Final tier 3.
Effort
Quick kitchen prep Peel the thin shell of the small single nut and eat it like a small chestnut, or score and roast it.
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. Prince William Forest Park Superintendent’s Compendium National Park Service, Prince William Forest ParkBacks up: picking rules
  5. Wolf Trap National Park for the Performing Arts, Compendium of Regulatory Provisions (2026 ver. 6/5/2026) National Park Service, Wolf Trap National Park for the Performing ArtsBacks up: picking rules
  6. 4VAC5-30-50. Flowers, plants, minerals, etc. Virginia Law Library (law.lis.virginia.gov)Backs up: picking rules
  7. Chestnuts in Virginia Virginia Places (virginiaplaces.org)Backs up: description
  8. Alleghany chinkapin fact sheet Virginia Tech DendrologyBacks up: description, season
  9. Castanea pumila (chinquapin) NC State Extension Gardener Plant ToolboxBacks up: description, season, habitat
  10. Update on latex allergy: New insights into an old problem (World Allergy Organization Journal, 2021) PubMed Central (NIH/NLM)Backs up: effort & ID risk
  11. iNaturalist research-grade observations of Castanea pumila within 25 km of downtown DC iNaturalistBacks up: findability
  12. Castanea pumila (Allegheny Chinkapin) (Digital Atlas of the Virginia Flora) Virginia Botanical Associates (Digital Atlas of the Virginia Flora)Backs up: habitat
  13. Annotated Checklist of the Vascular Plants of the Washington-Baltimore Area, Part I (Shetler & Orli, 2000) Smithsonian Institution, National Museum of Natural History, Department of BotanyBacks up: habitat
  14. Chinquapin Towson University, Glen ArboretumBacks up: habitat
  15. NPSpecies record: Castanea pumila in Prince William Forest Park (PRWI) National Park Service (IRMA NPSpecies)Backs up: habitat
  16. NPSpecies record: Castanea pumila in Fort Circle Parks (FOCI) National Park Service (IRMA NPSpecies)Backs up: habitat
  17. NPSpecies record: Castanea pumila in Rock Creek Park (ROCR) National Park Service (IRMA NPSpecies)Backs up: habitat
  18. NPSpecies record: Castanea pumila in Greenbelt Park (GREE) National Park Service (IRMA NPSpecies)Backs up: habitat
  19. NPSpecies record: Castanea pumila in George Washington Memorial Parkway (GWMP) National Park Service (IRMA NPSpecies)Backs up: habitat
  20. Purchasing and Roasting Chestnuts for the Holidays University of Missouri Integrated Pest ManagementBacks up: keeping
  21. USDA PLANTS Database: Castanea pumila (CAPU9), native status USDA NRCSBacks up: native or invasive status
  22. Virginia Invasive Plant Species List (effective date: September 2024) Virginia Department of Conservation and Recreation, Division of Natural HeritageBacks up: native or invasive status
  23. 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
  24. 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
  25. 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
  26. Invasive Plants in the District DC Department of Energy & EnvironmentBacks up: native or invasive status
  27. Aesculus hippocastanum (horsechestnut) NC State Extension Gardener Plant ToolboxBacks up: safety
  28. Chestnut oaks, beeches, and horsechestnuts The American Chestnut FoundationBacks up: safety
  29. Wild Edibles of Missouri (Jan Phillips) Missouri Department of ConservationBacks up: safety details
  30. Aesculus flava (Yellow Buckeye) NC State Extension Gardener Plant ToolboxBacks up: safety details
  31. Castanea, chestnut (Woody Plant Seed Manual, Agriculture Handbook 727) USDA Forest ServiceBacks up: season
  32. Acorn and Nut Identification Guide (Forestry Topic 60, Sept 2026) Virginia Department of ForestryBacks up: season, description
  33. Chinkapin (Castanea pumila) Plant Guide USDA NRCS National Plant Data CenterBacks up: season, description, uses, picking rules
  34. Castanea pumila (Fire Effects Information System) USDA Forest ServiceBacks up: season, habitat, description, uses, picking rules
  35. 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: uses, storage, keeping