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A Forager’s Year

Not on the calendar

American chestnut

Castanea dentata

Nut & seed nuts

Drawing: Britton & Brown, Illustrated Flora (1913)

Practically unavailable. Virginia atlas, Smithsonian and Maryland TACF sources confirm it is present near DC but almost entirely as non-fruiting sprouts; the only dependable nut-bearing trees nearby are restricted breeding orchards, so there is no legal, realistic harvest to put on a calendar.

Find
Elusive
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

Once a major eastern forest tree, now nearly gone as a mature tree because of chestnut blight. Sprouts from old roots can reach about 20 feet and bear a few nuts before blight kills them back. Leaves are thin, dull and canoe-shaped with hooked teeth, and buds are often red or orange. Burs hold 2-3 sweet nuts.

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. Chinese and hybrid chestnuts are far more likely than a true American chestnut. TACF’s ID service can confirm.

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 lookalike as other chestnuts: horse chestnut and buckeyes (Aesculus), highly poisonous. True chestnuts have simple, toothed, alternate leaves and bristly burs; Aesculus has palmately compound leaves (5-7 leaflets) and leathery capsules. Telling American from Chinese chestnut needs TACF’s service but is not a safety issue.
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
mid Sep–late Sep
Ends
late Oct

The Maryland chapter of The American Chestnut Foundation collects nuts from its Maryland orchard trees throughout September, with burs ripening by mid to late September. NC State Extension says nuts drop from September to October. Wild root sprouts can produce a few nuts before blight kills them back (NC State); the Woody Plant Seed Manual says such sprouts do so only occasionally. There are no DC iNaturalist fruiting records.

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: sourced

Start

sourced

Peak

sourced

End

sourced

Evidence

start: TACF Maryland Chapter Summer 2026 newsletter: 'We will be collecting chestnuts throughout the month of September' from its Maryland orchards. | peak: TACF Maryland Chapter newsletter: photo of 8 August shows burs 'half way to ripening by mid to late September'. | end: NC State Extension: burs open about first frost and 2-3 nuts drop to the ground in September to October. Woody Plant Seed Manual: chestnuts ripen August to October depending on species and location.

Where to look

Root sprouts on dry, acidic ridges in upland oak woods. Specific spots are withheld because wild trees are rare blight survivors that seldom bear nuts; leave any burs for restoration work.

Habitats
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

  • Same as other chestnuts: score and roast, boil, or dry and grind (Oregon State Extension)
  • Report a wild American chestnut to The American Chestnut Foundation, which identifies trees for free from a fresh 6-12 inch twig with mature leaves

Keeping

Refrigerate or freeze the rare nuts within a day or two of gathering.

Use within
within a few days
Keeps fresh
Handle like other chestnuts: refrigerate soon after gathering, about 2 months in the shell in the fridge, and expect 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: dry/dehydrate; canning: n/a (not shelf-canned)

    Dry them rock-hard and grind into flour (OSU).

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

    Score and roast; cure 3-5 days at room temperature first for sweetness (Missouri).

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

    Seal raw nuts in a non-ventilated freezer 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 North America (Appalachian region)
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
Elusive Estimate 179 = 134 research-grade iNaturalist sightings within 25 km + 67 needs-ID sightings counted at 46% (134 of the 294 research-grade Castanea sightings here are American chestnut) + 14 'cultivated' (planted) sightings (rule A); that is tier 3 by count (rule B). Rule D (scarce here): NC State Extension says that in the wild, after blight, it "may reach 20 feet tall and produce a few nuts before succumbing to the blight again". So only its planted sightings count: 14, which is tier 4. Final tier 4.
Effort
Quick kitchen prep Score and roast, or boil and peel, like other chestnuts; drying and grinding for flour is a 3.
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

27 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. Castanea dentata (American chestnut) NC State Extension Gardener Plant ToolboxBacks up: description, season, habitat
  7. Identification of American Chestnut The American Chestnut FoundationBacks up: description, uses, picking rules
  8. Update on latex allergy: New insights into an old problem (World Allergy Organization Journal, 2021) PubMed Central (NIH/NLM)Backs up: effort & ID risk
  9. iNaturalist research-grade observations of Castanea dentata within 25 km of downtown DC iNaturalistBacks up: findability
  10. 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
  11. Maryland Chapter: Orchards The American Chestnut Foundation, Maryland ChapterBacks up: habitat
  12. Chestnuts in Virginia Virginia Places (virginiaplaces.org)Backs up: habitat, description
  13. Castanea dentata (American Chestnut) (Digital Atlas of the Virginia Flora) Virginia Botanical Associates (Digital Atlas of the Virginia Flora)Backs up: habitat, description
  14. Purchasing and Roasting Chestnuts for the Holidays University of Missouri Integrated Pest ManagementBacks up: keeping
  15. USDA PLANTS Database: Castanea dentata (CADE12), native status USDA NRCSBacks up: native or invasive status
  16. Virginia Invasive Plant Species List (effective date: September 2024) Virginia Department of Conservation and Recreation, Division of Natural HeritageBacks up: native or invasive status
  17. 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
  18. 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
  19. 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
  20. Invasive Plants in the District DC Department of Energy & EnvironmentBacks up: native or invasive status
  21. Aesculus hippocastanum (horsechestnut) NC State Extension Gardener Plant ToolboxBacks up: safety
  22. Chestnut oaks, beeches, and horsechestnuts The American Chestnut FoundationBacks up: safety
  23. Wild Edibles of Missouri (Jan Phillips) Missouri Department of ConservationBacks up: safety details
  24. Aesculus flava (Yellow Buckeye) NC State Extension Gardener Plant ToolboxBacks up: safety details
  25. Castanea, chestnut (Woody Plant Seed Manual, Agriculture Handbook 727) USDA Forest ServiceBacks up: season
  26. Maryland Chapter Summer 2026 Newsletter The American Chestnut Foundation, Maryland ChapterBacks up: season, habitat, picking rules
  27. 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, safety, storage, keeping