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A Forager’s Year

No. 108

American plum

Prunus americana

wild plum, American wild plum

Fruit ripe fruit (pits removed; preserves, jellies)

Drawing: Britton & Brown, Illustrated Flora (1913)

Find
Elusive
Effort
Grab & eat
ID risk
Careful
Origin
native
Safety marks
  • Toxic parts
Uses
  • Eat raw / salad
  • Baking & desserts
  • Jam & jelly
  • Syrup & cordial
  • Juice & drinks
  • Wine & spirits
  • Dried fruit & leather

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

Picking: At least one park allows it. See Where you may pick.

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, recorded near DC (an iNaturalist sighting within 25 km, a DC street tree, or a Smithsonian listing for DC) and looking like the part you eat. Other lookalikes are still listed, marked “not recorded near DC” or as not looking like the part you eat. 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 native shrub or small tree, usually 10 to 20 feet tall, that suckers freely and can form thickets; its side branches are often thorn-like (NC State). The leaves are alternate, oval with a sharply tapering tip and sharply toothed edges, generally 2 to 4 inches long, dark green above and pale below (USDA NRCS). Clusters of 2 to 5 white, five-petaled flowers about 1 inch across open in early spring before the leaves (NC State). The fruit is a round, thick-skinned plum about 1 inch across, red-purple (some are yellow) with bright yellow, juicy flesh and a single stone (NC State; USDA NRCS). The skin is tough and sour, but the flesh becomes sweet when the fruit is fully ripe (Lady Bird Johnson Wildflower Center; NC State). NC State calls the raw fruit somewhat poor in quality and better for preserves and jellies.

Safety

The pits (seeds), leaves and stems contain cyanogenic glycosides, which release cyanide; NC State rates the poison severity as medium. NC State says a couple of pits swallowed by accident will not cause poisoning, but pits are more poisonous when crushed or ground or when the seeds are chewed, and fruit that has not been pitted should not be blended. Never crack, crush or grind the pits. The Maryland Poison Center lists plums among the stone fruits whose pits should be avoided; teach children to spit out pits (Poison Control). The Lady Bird Johnson Wildflower Center says every part of the tree except the flesh and skin of the plums contains hydrocyanic acid, and the University of Georgia Extension says the fruit itself is not affected. Do not make tea from the leaves, twigs or bark. People allergic to apples, pears, cherries or other members of the rose family should be cautious with plums (University of Georgia Extension), and the Maryland Poison Center lists plum among the fruits that can cause an allergic reaction in people allergic to birch pollen. The branches often carry short, sharp, thorn-like twigs (NC State; University of Georgia Extension). Harmless lookalikes are other wild plums. American plum has leaves 3 to 4 inches long and fruit about 1 inch across (University of Georgia Extension). Chickasaw plum’s leaves are shorter and narrower (1.5 to 3 inches) and fold upward along the midrib into a trough, and its fruit is only 1/3 to 1/2 inch across with a whitish bloom (University of Georgia Extension). Beach plum is a shrub of coastal dunes with smaller petals and blue-purple to purple-black fruit (Go Botany); it is endangered in Maryland (Maryland Natural Heritage Program) and should be left alone.

Lookalikes

  • Chickasaw plum Prunus angustifolia harmless (may be edible)

    Chickasaw plum’s leaves are shorter and narrower than American plum’s (1.5 to 3 inches long) and angle upward along the midrib into a trough, and its fruit is 1/3 to 1/2 inch across with a whitish bloom; American plum has leaves 3 to 4 inches long and fruit about 1 inch across. The two hybridize, and both are wild-harvested for their fruit (University of Georgia Extension). NC State lists Chickasaw plum’s pits, leaves and stems as poisonous, as for American plum.

  • Beach plum Prunus maritima harmless (may be edible)

    Go Botany says beach plum is sometimes confused with American plum: beach plum has petals 3-8 mm long and blue-purple to purple-black fruit, while American plum has petals 7-12 mm long and red to yellow fruit. Beach plum grows on coastal dunes and produces edible fruit (Go Botany), but it is listed as endangered in Maryland (Maryland Natural Heritage Program), so leave it alone.

Safety flags

Safety marks and flags: what this means

Deadly lookalike / Toxic lookalike: a cited source names a lookalike of that danger, recorded near DC (an iNaturalist sighting within 25 km, a DC street tree, or a Smithsonian listing for DC) and looking like the part you eat. Other lookalikes are still listed, marked “not recorded near DC” or as not looking like the part you eat. 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
No toxic lookalike is named: Chickasaw plum (shorter, narrower, trough-shaped leaves and fruit 1/3 to 1/2 inch across) and beach plum (blue-purple to purple-black fruit, on coastal dunes) are harmless relatives (University of Georgia Extension; Go Botany). But the pits, leaves and stems are cyanogenic (NC State: medium severity) and the pits end up in the harvest unless removed, so pit the fruit and never crack, crush or grind the stones.
Handling hazards
Thorns (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 Aug
Peak
early Aug–late Aug
Ends
late Sep

USDA NRCS says the fruit ripens from August to September and is usually harvested in August, when it turns dark purple; the Lady Bird Johnson Wildflower Center says it ripens to bright red in August or September. Farther south, NC State gives July and August for North Carolina, and the University of Georgia gives June to August in Georgia. No Maryland, Virginia or DC source gives a ripening date. Few ripe-fruit photos come from the region: in iNaturalist records from Maryland and Virginia, fruit is still green in early July and red from mid to late August. Pick fully colored plums; NC State says the flesh becomes sweet when the fruit is fully mature.

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, peak, end

Start

estimated: No Maryland, Virginia or DC source gives a date. USDA NRCS (range-wide) puts ripening in August, NC State’s July start is for North Carolina, farther south, and the regional photos show green fruit in early July and red fruit by mid-August.

Peak

estimated: No source names a peak for the region; August is the month USDA NRCS gives for the usual harvest and the overlap of every source’s ripening window.

End

estimated: The range-wide sources end ripening in September; with too few regional records to show when the fruit is gone, late September is the end of the documented window.

Evidence

start: USDA NRCS plant guide: 'fruit ripens from August to September' and 'Harvest the fruit in the summer when ripe (the fruit turns dark purple), usually in August.' NC State (North Carolina): plums 'which ripen in July and August'. iNaturalist MD/VA/DC research-grade fruiting records, photos checked by eye: green fruit on Jul 9, 2023 (Frederick, MD); red fruit on Aug 16, 2015, Aug 26, 2021 and Aug 31, 2021 (Virginia). | peak: USDA NRCS plant guide: harvest ripe fruit 'usually in August.' Lady Bird Johnson Wildflower Center: 'The fruit that follows ripens to a shiny, bright red in August or September.' | end: USDA NRCS plant guide: 'fruit ripens from August to September'. Lady Bird Johnson Wildflower Center: ripens 'in August or September.' iNaturalist MD/VA/DC fruiting records by week: weeks 33-35 (mid-August to early September) 4 records, then one in week 41 (October).

Where to look

Scarce near DC: thickets, old fields, fencerows and woods edges, with most sightings at Huntley Meadows Park in Fairfax County, where picking is not allowed. Prince William Forest Park (cherries and plums, 1 pint per day) and Virginia state parks such as Mason Neck and Leesylvania allow picking but have no logged American plum sightings; the C&O Canal allows edible fruits generally but sets no limit for plums, so it is ambiguous there (ask the park). Otherwise pick from private trees with permission.

Habitats
old fields & meadows, woods edges, trailsides & thickets, floodplain & stream-valley forest
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.

No picking here (1 place)
  • Huntley Meadows Park

    9 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 have no places. At-risk plants (butternut, nannyberry, American chestnut, ramps, riverbank goldenrod) get places like every other plant; each page says why the plant is at risk and gives any advice its sources give. 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

  • jelly, jam and preserves (NC State; USDA NRCS)
  • dried like prunes (NC State); halve and pit the plums first, or spread the pulp thin and dry it as fruit leather (Lady Bird Johnson Wildflower Center)
  • eat raw when fully ripe, spitting out the stone; the skin is tough and sour (NC State; Lady Bird Johnson Wildflower Center)
  • pies and other baked desserts (Lady Bird Johnson Wildflower Center; USDA NRCS)
  • syrup, juice and wine (University of Georgia Extension)
  • harvest ripe, undamaged fruit by hand early in the day, minding the short thorny branches, and chill it soon after picking (University of Georgia Extension)

Keeping

Keep unwashed in the refrigerator up to 5 days (University of Georgia Extension), or pit and freeze; NCHFP’s tested plum jelly can be canned in a boiling-water canner.

Use within
within a few days
Keeps fresh
Up to 5 days in the refrigerator, unwashed; plums keep ripening after picking (University of Georgia Extension).
Canning
lab-tested: plum jelly (NCHFP)
Keeping basis
specific to this plant

Ways to keep it

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

    Halve, pit and dry like prunes, or spread the pulp thin and dry it as fruit leather (Lady Bird Johnson Wildflower Center; NC State).

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

    NCHFP: wash, halve or quarter and pit firm, ripe plums, pack in cold 40 to 50 percent syrup, leave headspace and freeze.

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

    NCHFP plum sauce: boil the plums without water until soft, remove the pits and skins, cook the pulp down until thick, add 1 part sugar to 4 parts plums, cool and freeze.

  • Jam/jelly as researched: jam/jelly; canning: lab-tested: plum jelly (NCHFP)

    NCHFP has tested plum jelly recipes with a boiling-water canning process (plum jelly without pectin: crush the fruit, simmer 15 to 20 minutes, drip the juice through a jelly bag without squeezing). Pit the plums first, or crush the fruit without cracking the stones: NC State warns that crushed pits are more poisonous.

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
central & 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
Elusive Estimate 29 = 11 research-grade iNaturalist sightings within 25 km + 88 needs-ID sightings counted at 0.5% (11 of the 2,054 research-grade Prunus sightings here are American plum) + 18 'cultivated' (planted) sightings (rule A); that is tier 4 by count (rule B). Rule D does not apply: the Digital Atlas of the Virginia Flora calls it "Infrequent but widespread throughout" Virginia, which is not rare or very infrequent. Final tier 4.
Effort
Grab & eat Eat fully ripe plums raw and spit out the stone; jelly or preserves (cook, strain or pit without cracking the stones) 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

28 sources, each linked to the original.

  1. C&O Canal NHP Superintendent’s Compendium National Park ServiceBacks up: picking rules
  2. Prince William Forest Park Superintendent’s Compendium National Park Service, Prince William Forest ParkBacks up: picking rules
  3. Rock Creek Park Superintendent’s Compendium National Park ServiceBacks up: picking rules
  4. 4VAC5-30-50. Flowers, plants, minerals, etc. Virginia Law Library (law.lis.virginia.gov)Backs up: picking rules
  5. Plant Fact Sheet: American Plum, Prunus americana Marsh. USDA NRCS Plant Materials ProgramBacks up: description, uses
  6. iNaturalist research-grade observations of Prunus americana within 25 km of downtown DC iNaturalistBacks up: findability
  7. 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
  8. Prunus americana (American Wild Plum) (Digital Atlas of the Virginia Flora) Virginia Botanical Associates (Digital Atlas of the Virginia Flora)Backs up: habitat, findability
  9. Plum Jelly without Pectin National Center for Home Food Preservation (University of Georgia)Backs up: keeping
  10. Freezing Plums National Center for Home Food Preservation (University of Georgia)Backs up: keeping
  11. USDA PLANTS Database: Prunus americana (PRAM), native status USDA NRCSBacks up: native or invasive status
  12. Virginia Invasive Plant Species List (effective date: September 2024) Virginia Department of Conservation and Recreation, Division of Natural HeritageBacks up: native or invasive status
  13. 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
  14. 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
  15. 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
  16. Invasive Plants in the District DC Department of Energy & EnvironmentBacks up: native or invasive status
  17. Pitfalls of Fruit Pits and Seeds (eAntidote blog, June 22, 2023) Maryland Poison CenterBacks up: safety
  18. Are cherry pits really poisonous? Poison Control (National Capital Poison Center)Backs up: safety
  19. Prunus americana Marshall (American Plum) Go Botany (Native Plant Trust)Backs up: safety
  20. Prunus maritima Marshall (Beach Plum) Go Botany (Native Plant Trust)Backs up: safety
  21. List of Rare, Threatened, and Endangered Plants of Maryland (March 2026) Maryland DNR Wildlife and Heritage Service, Natural Heritage ProgramBacks up: safety
  22. Prunus angustifolia (Chickasaw Plum) NC State Extension Gardener Plant ToolboxBacks up: safety details
  23. American plum research-grade fruiting observations, Maryland, Virginia and DC, with photos iNaturalistBacks up: season
  24. American plum research-grade fruiting observations, Maryland, Virginia and DC, by week iNaturalistBacks up: season
  25. Prunus americana (American Plum, American Wild Plum, Wild Plum) NC State Extension Gardener Plant ToolboxBacks up: season, description, uses, habitat, safety, picking rules, native or invasive status, keeping
  26. Prunus americana (American Plum, Wild Plum) Lady Bird Johnson Wildflower CenterBacks up: season, description, uses, habitat, safety, keeping
  27. Plant Guide: Wild Plum, Prunus americana Marsh. USDA NRCS National Plant Data CenterBacks up: season, uses, description
  28. Wild Harvesting American Plum and Chickasaw Plum in Georgia (WSFNR-21-81A, 2021) University of Georgia Warnell School of Forestry and Natural Resources and UGA Cooperative ExtensionBacks up: season, uses, safety, storage, keeping