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A Forager’s Year

No. 77

Ginkgo

Ginkgo biloba

ginnan (the seeds); female trees only

Nut & seed seed kernel (after removing pulp and shell, cooked)

Drawing: L. H. Bailey, Standard Cyclopedia of Horticulture (1914–17)

Find
Common in the right habitat
Effort
Real work
ID risk
Careful
Origin
non-native
Safety marks
  • Toxic parts
  • Cook first
  • Spray risk
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

Ginkgo is an ancient tree with fan-shaped leaves, and male and female trees are separate. Only females drop the plum-like yellow-orange 'fruits', whose fleshy coat smells strongly of rancid butter or vomit (butyric acid). Inside is a hard, smooth, cream-colored shell. Cooked, the kernel is soft and slightly chewy, with a mild, faintly sweet, chestnut-like taste.

Safety

TWO HAZARDS. (1) Fruit pulp: the fleshy coat contains ginkgolic acids and bilobol, which cause a rash like poison ivy, plus butyric and hexanoic acids that irritate skin, eyes and airways. Wear gloves and eye protection, and never eat the pulp (UGA; NC State). (2) The kernel contains ginkgotoxin (4'-O-methylpyridoxine), which blocks vitamin B6 and can cause vomiting and seizures. Cooking does NOT destroy it (Hong Kong Centre for Food Safety; 2020 case report). Eating 10-50 cooked seeds at once can cause acute poisoning, and children are especially susceptible. Advice: never eat raw or green seeds. Eat only a few cooked seeds a day. UGA: none for children under 6; at most 5 for older children and for adults new to them (try one and wait 4 hours). Children have been poisoned by as few as 7 seeds (2020 case review), and Hong Kong’s Centre for Food Safety says to limit intake to a few seeds a day, especially for children. Treatment is vitamin B6, so seek care for vomiting or seizures after eating them. Also note: DDOT sprays female street ginkgos each spring with chlorpropham ('Shield'), a potato sprout inhibitor. DDOT calls it harmless to people, but no source addressed eating seeds from sprayed trees.

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
The tree is unmistakable, but the fleshy pulp is a strong irritant and the kernel itself is toxic beyond a few seeds (ginkgotoxin; vomiting, seizures). The safety depends on handling and dose rather than on telling it from another plant.
Handling hazards
Irritant sap/pulp (moderate)
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
late Sep
Peak
late Oct–late Nov
Ends
early Dec

In DC, November is usually the main ginkgo drop, though in early years seeds are falling heavily by mid-October (DCist). Seeds can be picked up from late fall into early winter (USDA Woody Plant Seed Manual), and fallen fruit has lingered on downtown sidewalks into December (DCist). For eating, UGA Extension recommends collecting early in the season, when starch is highest. DDOT sprays female street ginkgos in spring to cut fruiting, so crops on treated trees vary from year to year (DCist). Start and end are estimates. iNaturalist does not allow fruiting annotations on ginkgo, so there are no stage counts.

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: start, end

Start

estimated: UGA is from Georgia and no DC source dates the first drop; late September allows for early drops while noting DC’s main fall comes later.

Peak

sourced

End

estimated: No source gives an end date for DC; early December reflects the Manual’s early-winter collection and the December 2008 DC report. UGA advises early collection for eating, so late seeds are second-best.

Evidence

start: UGA Extension (Georgia): seeds begin to fall in early fall, and mid-September collection gives the most starch for eating. Baltimore Brew: in Baltimore, trees are laden with ripening fruit when October arrives. | peak: DCist (Oct 2011): 'November is usually prime ginkgo dropping season', though that year fruit was already falling heavily by mid-October. DCist (Oct 2009): the worst of the 2008 fall came 'well into November'. | end: Woody Plant Seed Manual: seeds are cast in fall after the first frost and can be collected from the ground or the tree from late fall through early winter. DCist (10 Dec 2008): fallen fruit and its smell lingered on downtown streets longer than usual. Washingtonian: DC ginkgo leaves turn around the week of Nov 6 (2022) and drop within days.

Where to look

Female street trees in Georgetown, Dupont Circle, Logan Circle, Shaw and Columbia Heights (follow the smell in fall); no DDOT rule addresses picking street-tree fruit, so take fallen seeds only and never damage the tree.

Habitats
street & yard trees (planted)
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

None of the most-logged places allows picking.

Ask first: rules unclear or not checked

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

    2 sightings · Legal to pick: ambiguous · see them on iNaturalist

    Ambiguous: the C&O compendium allows edible fruits, nuts and berries generally but sets no limit for this one; ask the park first.

No picking here (1 place)
  • Scott’s Run Nature Preserve

    2 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.

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

  • Gather fallen seeds into a plastic bucket wearing long gloves and eye protection. Soak a few days so the flesh rots, then squeeze and scrub it off over 3-4 washes and discard floaters (UGA Extension)
  • Dry the cleaned seeds 1-7 days. Light roasting or boiling, then salting, are the usual methods; seeds split open like pistachios when cooked (UGA Extension)
  • Toast the shells in a dry pan, crack, peel the inner skin, then toast with a little oil and salt until translucent (Baltimore Brew)
  • Japanese and Korean dishes: chawanmushi (savory egg custard), takikomi gohan (mixed rice), oden and soups, or roasted with salt (Just One Cookbook)

Keeping

Clean the seeds within a few days of gathering (gloves and eye protection), dry them, then cook them promptly or freeze them.

Use within
within a few days
Keeps fresh
Soak a few days to rot off the foul flesh, then scrub, rinse and dry the cleaned seeds 1-7 days (UGA). For food use, UGA advises cooking cleaned seeds promptly for best quality. Cleaned seeds freeze well in plastic bags (Baltimore Brew). Always cook them and eat only a few.
Keeping basis
specific to this plant

Ways to keep it

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

    Light roasting or boiling, then salting, is the usual preparation (UGA); eat in small portions.

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

    Freeze the cleaned, dried seeds in plastic bags (Baltimore Brew).

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
non-native
Native range
East Asia (south-central & southeastern China)
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 821 = 13 research-grade iNaturalist sightings within 25 km + 808 'cultivated' (planted) sightings (rule A); that is tier 2 by count (rule B). Only female ginkgos bear the nuts. DC’s street-tree inventory lists 724 living female ginkgos (728 counting trees recorded dead, the figure in the habitat text), 3,023 living male and 1,251 not sexed, and the 'cultivated' iNaturalist records include male trees, so the estimate counts trees, not nut-bearing trees. Final tier 2.
Effort
Real work Wearing gloves and eye protection, rub or soak off the foul pulp and scrub the seeds clean, dry them a couple of days, then toast, crack and peel; UGA’s soak-to-rot method takes days to a week.
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

24 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. Ginkgo trees are about to peak: here’s where to enjoy the foliage this fall WashingtonianBacks up: description, season
  4. iNaturalist research-grade observations of Ginkgo biloba within 25 km of downtown DC iNaturalistBacks up: findability
  5. UFA Street Trees (DC Urban Forestry street-tree inventory), Ginkgo records District of Columbia (DDOT Urban Forestry Division, via DC GIS)Backs up: habitat
  6. D.C. is spraying ginkgo trees to prevent the vomit stench DCistBacks up: habitat, safety, season
  7. USDA PLANTS Database: Ginkgo biloba (GIBI2), native status USDA NRCSBacks up: native or invasive status
  8. Virginia Invasive Plant Species List (effective date: September 2024) Virginia Department of Conservation and Recreation, Division of Natural HeritageBacks up: native or invasive status
  9. 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
  10. 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
  11. 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
  12. Invasive Plants in the District DC Department of Energy & EnvironmentBacks up: native or invasive status
  13. The Ginkgo - A Living Fossil with Poisonous Seeds (Food Safety Focus, Dec 2018) Centre for Food Safety, Hong Kong SAR GovernmentBacks up: safety
  14. Epileptic Seizure from Ginkgo Nut Intoxication in an Adult (Case Reports in Emergency Medicine, 2020) PubMed Central (NIH/NLM)Backs up: safety
  15. An Adult Case of Generalized Convulsions Caused by the Ingestion of Ginkgo biloba Seeds with Alcohol (Internal Medicine, 2020) PubMed Central (NIH/NLM)Backs up: safety
  16. No love for the lady ginkgos Ecological Society of America (EcoTone blog)Backs up: safety
  17. Ginkgo biloba (ginkgo) NC State Extension Gardener Plant ToolboxBacks up: safety, description, native or invasive status
  18. Ginkgo Seed Collection & Preparation (FOR03-21, Kim D. Coder, 2003) University of Georgia Warnell School of Forest Resources / Cooperative ExtensionBacks up: safety, uses, season, keeping
  19. Ginkgo biloba, ginkgo (Woody Plant Seed Manual, Agriculture Handbook 727) USDA Forest ServiceBacks up: season
  20. Ginkgo season starts early, city starts spraying (Oct 2011) DCistBacks up: season, habitat
  21. Is the ginkgo situation better this year? (Oct 2009) DCistBacks up: season, habitat
  22. Ginkgo fruit (topic page, incl. 'What do you think ginkgo fruit smells like?', Dec 2008) DCistBacks up: season, habitat
  23. Ginkgo (Baltimore Urban Forager guest post) Baltimore BrewBacks up: season, uses, safety, keeping
  24. Ginkgo nuts Just One CookbookBacks up: uses, description