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A Forager’s Year

No. 1

Maple

Acer rubrum, A. saccharinum, A. negundo, A. saccharum

red, silver, box elder and sugar maple

Sap sap (boiled to syrup)

Drawing: Britton & Brown, Illustrated Flora (1913)

Find
Everywhere
Effort
Project
ID risk
Beginner
Origin
native
Uses
  • Syrup & cordial

Season

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

in season peak

What these mean

Find

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

Effort

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

ID risk

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

Native or not, and the invader stars

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

Seasons

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

What it looks like

Maple sap is a clear, faintly sweet liquid, about 2% sugar, that runs on freeze-thaw cycles in late winter. Boiling it down to about 66% sugar makes syrup. It takes about 40 gallons of sap to make a gallon of syrup on average (Penn State Extension), or 40-60 gallons by Virginia State Parks' figure. Virginia State Parks puts red and silver maple sap a little lower in sugar (1.5-2%) than sugar maple (2-2.5%). A Virginia study found box elder, and to a lesser degree silver maple, the best substitutes for sugar maple; in that study red maple sap was about as sweet as sugar maple’s but yielded little.

Safety

The sap itself has no notable hazard. Penn State notes syrup quality depends on how sap is collected and handled, so keep collection clean. Be sure the tree is a maple (or box elder) before tapping.

ID risk
Beginner
Why
No toxic lookalike is named; confirm the tree is a maple or box elder before tapping.
Soil risk
low
ID risk: what this means

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

Soil risk: what this means

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

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

When to pick

Starts
late Dec
Peak
early Feb–late Feb
Ends
early Mar

Maple sap runs on freeze-thaw cycles, when days are above freezing and nights below. Virginia Cooperative Extension’s tapping calendar for southwest Virginia runs from late December through February, with taps going in from mid-December to mid-January, and Virginia State Parks says trees can be tapped in January and run for 4 to 6 weeks. Around DC, February is the main month: Brookside Nature Center in Wheaton holds its maple sugaring programs then (Montgomery Parks), and Fairfax County’s Colvin Run Mill boils sap in late February. Tapping too early lets the hole seal over (Missouri Dept. of Conservation). The season ends when the trees bud or the weather stays warm (Virginia State Parks). Around DC red maples flower mostly in March (iNaturalist), so early March is a rough end. Runs depend on the weather from year to year.

How the dates were worked out

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

Season basis: estimated: end

Start

sourced

Peak

sourced

End

estimated: No source gives a DC end date; early March allows for late freeze-thaw runs before red maple buds break.

Evidence

start: Virginia Cooperative Extension tapping calendar (SW Virginia): the maple-tapping arrow starts in the last third of December and runs to the end of February; taps go in mid-December to mid-January. Virginia State Parks (Claytor Lake): trees can be tapped in January if days thaw and nights freeze. | peak: Close-in programs run in February: Montgomery Parks' Brookside Nature Center (Wheaton) treats February as maple sugaring month, with Maple Sugar Walks February 6-23; Fairfax County Park Authority’s Colvin Run Mill boil-down on Feb 22, 2026 ('the sap is rising and the maple trees are tapped'); Robinson Nature Center (Howard Co.) on Feb 26. A Dumfries, VA school tapped red maples in the first week of February. | end: VCE’s arrow ends at the end of February. Virginia State Parks: sap flows only 4-6 weeks, and the season ends when the trees bud or temperatures warm. DC iNat red maple flowering records rise from late February and peak in week 11 (mid-March); box elder flowers late March to mid-April.

Where to look

Red, silver and box elder maples are everywhere on streets and in floodplains (Rock Creek Park, Four Mile Run, the C&O towpath), but tapping is not allowed in any park; tap only your own trees or a consenting neighbor’s.

Habitats
street & yard trees (planted), 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 (5 places)
  • Rock Creek Park

    1087 sightings · Legal to pick: no · see them on iNaturalist

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

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

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

    Look but don’t pick: the C&O Canal compendium covers only edible fruits, nuts, berries and mushrooms, and NPS parks can never designate leaves, flowers, roots or sap. Of these, 33 are at Carderock.

  • Four Mile Run stream valley (Arlington/Alexandria)

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

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

  • Mount Vernon Trail

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

    Look but don’t pick: GW Memorial Parkway sites (incl. Great Falls VA, Theodore Roosevelt Island, Dyke Marsh) designate nothing for gathering.

  • Huntley Meadows Park

    127 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

  • Drill a 5/16-inch hole about 2 inches deep at a slight downward angle and insert a spout with a bucket or bag (Virginia Cooperative Extension)
  • Expect about 10-15 gallons of sap per tree per season, and roughly 1 gallon of syrup per 8 taps (Virginia Cooperative Extension)
  • Boil sap down to syrup at about 66% sugar. Check with a refractometer, hydrometer or candy thermometer (Virginia Cooperative Extension); about 40 gallons of sap per gallon of syrup on average (Penn State Extension)
  • Practicality around DC: a workable backyard hobby on your own maples or box elders, but yields are small. Plan on 40-60 gallons of sap per gallon of syrup (Virginia State Parks); a Dumfries, VA school class boiled 80 gallons of red maple sap down to 1 gallon (Arlington Catholic Herald)

Keeping

Keep collected sap at 38°F or colder and boil it within a week (or freeze it); refrigerate syrup once opened.

Use within
within a few days
Keeps fresh
Raw sap spoils like milk. Keep it at 38°F or colder, or packed in snow in the shade, and boil it within about 7 days, or freeze it. Discard sap that looks yellow or milky or smells off (Virginia DCR).
Canning
hot-bottled syrup, shelf-stable (Virginia DCR)
Keeping basis
specific to this plant

Ways to keep it

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

    Freeze surplus sap until you have enough to boil (Virginia DCR).

  • Syrup as researched: syrup/cordial; canning: hot-bottled syrup, shelf-stable (Virginia DCR)

    Boil to syrup at about 66% sugar and bottle it hot (180-200°F) in clean, sanitized jars. Unopened syrup keeps indefinitely; refrigerate it after opening, up to about 2 years (Virginia DCR).

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

All four named maples native. If tapping street trees, note Norway maple (Acer platanoides, European) is introduced and ranked Medium by VA DCR, MISC-listed, and in the Plant Invaders field guide (p. 111).

Origin
native
Native range
North America (A. negundo across most of the continent)
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
Everywhere Estimate 9,832 = 7,475 research-grade iNaturalist sightings within 25 km + 1,957 needs-ID sightings counted at 88% (in the October 5 genus count, 7,479 of the 8,515 research-grade Acer sightings here were red, silver, boxelder or sugar maple) + 638 'cultivated' (planted) sightings (rule A); that is tier 1 by count (rule B). Rule C (everyday place) is met: DC’s street-tree inventory lists 17,026 living red, silver, boxelder and sugar maples, more than one per km of DC sidewalk (2,406). Final tier 1.
Effort
Project Drill a 5/16-inch tap hole, set a spout and bucket, collect sap through the season and boil it down about 40:1 to syrup checked with a hydrometer or thermometer.
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

26 sources, each linked to the original.

  1. D.C. is spraying ginkgo trees to prevent the vomit stench DCistBacks 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. Comparative Analysis of Four Maple Species for Syrup Production in South-Central Appalachia (Peters et al., 2020) Journal of Agriculture, Food Systems, and Community Development (UVA-Wise authors)Backs up: description
  5. DC street-tree inventory (DDOT Urban Forestry, UFA Street Trees layer): living trees by species, queried 2026-10-05 (17,026 living red, silver, boxelder and sugar maples) District of Columbia (DDOT Urban Forestry Division, via DC GIS)Backs up: findability
  6. iNaturalist research-grade observations of Acer rubrum + A. saccharinum + A. negundo + A. saccharum within 25 km of downtown DC iNaturalistBacks up: findability
  7. Acer rubrum (red maple) Master Gardeners of Northern VirginiaBacks up: habitat
  8. USDA PLANTS Database: Acer rubrum (ACRU), native status USDA NRCSBacks up: native or invasive status
  9. USDA PLANTS Database: Acer saccharinum (ACSA2), native status USDA NRCSBacks up: native or invasive status
  10. USDA PLANTS Database: Acer negundo (ACNE2), native status USDA NRCSBacks up: native or invasive status
  11. USDA PLANTS Database: Acer saccharum (ACSA3), native status USDA NRCSBacks up: native or invasive status
  12. 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
  13. Virginia Invasive Plant Species List (effective date: September 2024) Virginia Department of Conservation and Recreation, Division of Natural HeritageBacks up: native or invasive status
  14. 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
  15. 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
  16. Invasive Plants in the District DC Department of Energy & EnvironmentBacks up: native or invasive status
  17. Maple Syrup Tapping Demo flyer (Seneca Creek State Park) Maryland Department of Natural ResourcesBacks up: season, habitat
  18. Maple Sugaring & Syrup Tasting Event Howard County Recreation & Parks (MD)Backs up: season, habitat
  19. Montgomery Parks February nature center programs (Maple Sugar Walk, Feb 6-23) Montgomery Parks (M-NCPPC)Backs up: season, habitat
  20. February is Maple Sugaring Month at Brookside Nature Center (Feb 2018) Montgomery Community Media (MyMCMedia)Backs up: season, habitat
  21. Maple Syrup Boil Down, Colvin Run Mill (Feb 22, 2026) Fairfax County Park AuthorityBacks up: season, habitat
  22. Maple Sugaring Missouri Department of ConservationBacks up: season, uses
  23. Tree syrup in Virginia (Woods & Wildlife Conference, Feb 2020; Phil Meeks) Virginia Cooperative Extension (Virginia Tech)Backs up: season, uses, description
  24. How to make maple syrup (Claytor Lake State Park handout) Virginia Department of Conservation and Recreation (Virginia State Parks)Backs up: season, uses, description, keeping
  25. Students tap into sweet science (Dumfries, VA) Arlington Catholic HeraldBacks up: season, uses, habitat
  26. Maple Syrup Penn State ExtensionBacks up: uses, safety, description, keeping