No. 32
Japanese honeysuckle
Lonicera japonica
Flowers, buds & pollen flower nectar (and flowers); NOT the berries
Drawing: Britton & Brown, Illustrated Flora (1913)
- Find
- Everywhere
- Effort
- Grab & eat
- ID risk
- Careful
- Origin
- non-native ★★★
- Safety marks
- Deadly lookalike
- Toxic parts
- Spray risk
- Uses
- Eat raw / salad
- Cooked vegetable / soup
- Juice & drinks
Season
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
in season peak
What these mean
Find
1 Everywhere · 2 Common in the right habitat · 3 Patchy · 4 Elusive. This is about how much there is, not whether you may pick it. It is based on iNaturalist sightings within 25 km (about 15 miles) of downtown DC, counted on October 3, 2026. The four rules that each plant’s “Find” reason refers to: (A) the estimate is the confirmed sightings, plus the unconfirmed ones (scaled down where the plant has lookalikes in its genus), plus the sightings marked as planted; (B) the tier by estimate: 1,500 or more is tier 1, 250–1,499 tier 2, 50–249 tier 3, under 50 tier 4; (C) tier 1, Everywhere, also needs a source saying the plant is common in lawns, sidewalks, yards or gardens, vacant lots or towns, or at least one DC street tree of it per km of sidewalk, otherwise it is tier 2; (D) if a reliable source says the plant is rare in this region, or that wild plants rarely bear the harvest, only planted sightings count. iNaturalist is a website and phone app where people post photos of the plants and animals they see. A sighting is “research grade” when other users have confirmed what it is; “needs ID” sightings are not confirmed yet, and “cultivated” ones are marked as planted.
Effort
1 Grab & eat · 2 Quick kitchen prep (under about 30 minutes) · 3 Real work (hours, or cooking needed for safety) · 4 Project (days or equipment). Scored on the simplest worthwhile use; each plant’s page says why.
ID risk
How hard it is to harvest safely. Beginner: no dangerous lookalike, and the edible part is not easily confused with a toxic part. Careful: a toxic lookalike, or toxic parts that end up in the harvest unless removed (for example elderberry stems, unripe ground cherries), or other parts of the plant rated medium-or-higher toxicity, with reliable features to separate them. Expert only: a potentially deadly lookalike that is hard to separate, or (for not-recommended harvests like pokeweed) a plant whose safe preparation can’t be guaranteed. Toxic parts that are obviously separate and thrown away anyway (pits, seeds, skins) don’t raise it; the Toxic parts mark carries that warning.
Native or not, and the invader stars
Origin is where the plant comes from: native, non-native, or mixed (the harvest covers both). The stars rate plants on invasive plant lists: ★★★ Virginia DCR “High” or Maryland prohibited invasive · ★★ Virginia “Medium” · ★ Virginia “Low” · ☆ listed only by the Maryland Invasive Species Council or the Mid-Atlantic Plant Invaders guide (advisory) · no stars: native or not listed.
Safety marks and flags
Deadly lookalike / Toxic lookalike: a cited source names a lookalike of that danger. Deadly means a source says eating it may be fatal or calls it deadly, or NC State rates it high severity with life-threatening symptoms (sources sometimes disagree; for example Virginia creeper). Each plant’s Lookalikes list says how to tell them apart; “harmless (may be edible)” lookalikes are listed so you know a mix-up isn’t dangerous. Cook first: cooking is needed for safety (for daylilies it is a precaution, not a sourced requirement). Eat in moderation: a source says to limit quantity or frequency (for example oxalates in sorrels and dock, ginkgotoxin, safrole). Spray risk: a source says the plant is commonly treated with herbicide in parks or lawns (invasive control, lawn weeds) or, for ginkgo, sprayed to stop fruiting. Contamination: a source says the plant concentrates pollutants. Each plant’s Safety flags list gives the details and sources.
Seasons
Start, peak and end are given in thirds of a month: early, mid or late. A plant counts as in season for a month if it is in season at any point in that month. Some greens and roots have a second window, in spring or fall; their page shows each window. A season that runs across New Year is shown as one window.
What it looks like
A semi-evergreen twining vine that often keeps some leaves into winter, with opposite oval leaves and paired, tubular, two-lipped flowers that open white and age to yellow, with a strong sweet fragrance. The nectar can be sucked from the flowers.
Safety
Nectar and flowers only. The black berries contain saponins and can cause vomiting, diarrhea and worse if eaten in quantity; they are not food. Don’t confuse with Carolina jessamine (Gelsemium sempervirens), a highly poisonous vine with golden-yellow funnel-shaped flowers that NC State lists as a honeysuckle look-alike.
Lookalikes
Carolina jessamine Gelsemium sempervirens deadly
Carolina jessamine has golden-yellow, funnel-shaped flowers; Japanese honeysuckle has paired, two-lipped tubular flowers that open white and age to yellow.
- Gelsemium sempervirens (Carolina Jessamine) NC State Extension Gardener Plant Toolbox
- Lonicera japonica (Japanese Honeysuckle) NC State Extension Gardener Plant Toolbox
- Invasive Alien Plant Species of Virginia: Japanese Honeysuckle Virginia Department of Conservation and Recreation
Safety flags
Spray risk
Listed invasive (Virginia DCR high rank). Virginia DCR recommends glyphosate where mowing or burning is impractical, and the Virginia Dept. of Forestry gives foliar glyphosate rates; vines on forest edges in managed natural areas may be treated.
- Invasive Alien Plant Species of Virginia: Japanese Honeysuckle Virginia Department of Conservation and Recreation
- Non-Native Invasive Plant Species Control Treatments (Forestry Topic 31, Oct. 2018) Virginia Department of Forestry
- Virginia Invasive Plant Species List (effective date: September 2024) Virginia Department of Conservation and Recreation, Division of Natural Heritage
- Integrated Pest Management Program Montgomery Parks (M-NCPPC)
Toxic parts
The black berries contain saponins and can cause vomiting and diarrhea if eaten in quantity.
- Lonicera japonica (Japanese Honeysuckle) NC State Extension Gardener Plant Toolbox
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
- Carolina jessamine (Gelsemium), highly poisonous, is listed by NC State as a look-alike; it has golden-yellow funnel-shaped flowers, unlike honeysuckle’s paired white-to-yellow tubular flowers. The black honeysuckle berries are not food.
- Soil risk
- moderate
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
Window 1
- Starts
- late Apr
- Peak
- mid May–late May
- Ends
- late Jun
Window 2
- Starts
- early Jul
- Peak
- –
- Ends
- mid Nov
Two windows. The main bloom (late Apr to late Jun) peaks in mid to late May around DC (iNaturalist), when there are enough flowers for a real harvest. After that the vine keeps putting out scattered flowers into autumn (University of Maryland Extension; NC State Extension); around DC flowering records continue into mid November (iNaturalist). Late flowers are fine for sipping nectar but too few to gather in quantity.
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
Window 1: Start
sourced
Window 1: Peak
sourced
Window 1: End
sourced
Window 1: Evidence
start: DC iNaturalist flowering records by third of the month (days 1-10, 11-20, 21-end): mid April 1 (Apr 19), late April 6 (Apr 25-30, in four different years, all in the City Nature Challenge week, Apr 24-May 1), early May 11; budding records 18 in late April. FEIS: flowering from April in the Carolinas and southern Appalachians. | peak: DC iNaturalist flowering records by third of the month (days 1-10, 11-20, 21-end): May 11/30/49, early June 11 (90 of 156 flowering records are in May). | end: DC iNaturalist flowering records by third of the month (days 1-10, 11-20, 21-end): June 11/5/4, July 3/1/3. FEIS: West Virginia May-July.
- Research-grade observations of Japanese honeysuckle (Lonicera japonica) within 25 km of DC, by month (flowering) iNaturalist
- Research-grade observations of Japanese honeysuckle (Lonicera japonica) within 25 km of DC, by month (flower budding) iNaturalist
- api.inaturalist.org/v1/observations/histogram
- api.inaturalist.org/v1/observations/histogram
- Lonicera japonica (Fire Effects Information System species review) USDA Forest Service
Window 2: Start
sourced
Window 2: Peak
Window 2: End
sourced
Window 2: Evidence
start: UMD Extension: the long bloom period begins around late spring or early summer and lasts into autumn. NC State: blooms from late spring through most of summer, sometimes into fall. DC iNaturalist: 7 flowering records in July. | peak: DC iNaturalist flowering records: 7-11 a month from July to November. | end: DC iNaturalist: 7 flowering records in November (3 in early and 4 in mid November), none in December. UMD Extension: bloom lasts into autumn.
- Japanese Honeysuckle University of Maryland Extension
- Lonicera japonica (Japanese Honeysuckle) NC State Extension Gardener Plant Toolbox
- Research-grade observations of Japanese honeysuckle (Lonicera japonica) within 25 km of DC, by month (flowering) iNaturalist
- api.inaturalist.org/v1/observations/histogram
Where to look
Fencerows, thickets, woods edges and roadsides everywhere; the vines in Rock Creek Park and Huntley Meadows are look-only, but neighborhood fences and alleys (with permission) have plenty.
- Habitats
- disturbed ground & waste places, old fields & meadows, woods edges, trailsides & thickets
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
Look but don’t pick: Rock Creek Park’s compendium bans gathering any fruit, nut, berry, seed or greenery.
- Huntley Meadows Park
Look but don’t pick: Fairfax County parks ban removing any plant part without written permission.
- C&O Canal NHP (towpath, Georgetown to Great Falls MD and beyond)
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, 9 are at Carderock.
- Rock Creek Regional Park (MD)
Look but don’t pick: Montgomery/Prince George’s parks (M-NCPPC) ban harvesting vegetation without a permit.
- Four Mile Run stream valley (Arlington/Alexandria)
Look but don’t pick: Arlington County park rules (flora shall not be removed or disturbed) and Alexandria’s permit rule both apply.
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.
Where you may pick
Highly invasive; pulling vines is helpful. On National Park Service land around DC (Rock Creek Park and other NPS units) gathering leaves, flowers, roots or other non-fruit plant parts is prohibited, because 36 CFR 2.1(c) lets a park designate only fruits, berries and nuts; Rock Creek’s compendium also bars gathering fruits, nuts, berries, seeds, mushrooms or cut greenery. Get permission before picking in county or regional parks or on private land.
- (no listed park)
Private land with the owner’s permission only
Where you may pick: what this means
For each park system: “yes” where its current rules (the park’s compendium or regulation) allow this plant or part, with the limit; “ambiguous” where the wording may or may not cover it, so ask the park; “no” where it is not allowed. Rock Creek Park, the GW Parkway sites (including Great Falls VA and Theodore Roosevelt Island), the National Mall, Montgomery and Prince George’s parks, Maryland state parks, and Fairfax and Arlington parks prohibit picking. Wolf Trap National Park for the Performing Arts allows blackberries and raspberries (one gallon per person per day) and chestnuts (one gallon per person per day). National Park Service rules are reissued every year; other parks change theirs from time to time, so check the park’s current rules. The Where you may pick page has every park’s rules.
Ways to use it
- nectar sipped from the flower
- flowers in some Chinese dishes
Keeping
Use the flowers the day you pick them. Flowers only, never the berries.
- Use within
- pick & use same day
- Keeps fresh
- Nectar is sipped on the spot; flowers wilt within hours, so use the same day (general guidance for edible flowers). Univ. of Minnesota: harvest edible flowers the day you will use them, no more than one day early; wash gently, dry, and refrigerate in plastic bags until use.
- Keeping basis
- general guidance for its type
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 (Japan, Korea, Manchuria, China)
- Invader credit
- ★★★
- Virginia invasive rank
- High
- Maryland invasive status
- Advisory (MISC list)
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 2,841 = 2,593 research-grade iNaturalist sightings within 25 km + 819 needs-ID sightings counted at 27% (in the October 5 genus count, 2,594 of the 9,693 research-grade Lonicera sightings here were Japanese honeysuckle) + 29 'cultivated' (planted) sightings (rule A); that is tier 1 by count (rule B). Rule C (everyday place) is met: University of Maryland Extension says "This vine is a common weed in commercial nursery operations as well as gardens, particularly when natural areas overrun with Japanese honeysuckle are nearby". Final tier 1.
- Effort
- Grab & eat Pick a fresh flower and suck the nectar from its base.
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
25 sources, each linked to the original.
- Rock Creek Park Superintendent’s Compendium National Park ServiceBacks up: picking rules
- Lonicera japonica (Japanese Honeysuckle) NC State Extension Gardener Plant ToolboxBacks up: description, season, uses, safety, native or invasive status
- iNaturalist research-grade observations of Lonicera japonica within 25 km of downtown DC iNaturalistBacks up: findability
- Edible flowers University of Minnesota ExtensionBacks up: keeping
- How to Make Flower Petal Jelly Safely University of Maine Cooperative ExtensionBacks up: keeping
- Is jelly made from dandelion or grape hyacinth tea considered safe? Oregon State University Extension ServiceBacks up: keeping
- Herbs (drying) National Center for Home Food Preservation (University of Georgia)Backs up: keeping
- Food Preservation: Preserving Herbs—Freezing and Drying (HYG-5360) Ohio State University ExtensionBacks up: keeping
- USDA PLANTS Database: Lonicera japonica (LOJA), native status USDA NRCSBacks up: native or invasive status
- 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
- Invasive Plant List (Tier 1, Tier 2 and 'Additional plants considered'; last updated January 19, 2023; superseded) Maryland Department of AgricultureBacks up: native or invasive status
- District of Columbia Wildlife Action Plan, Draft 2025 Update, Chapter 6: Threats DC Department of Energy & EnvironmentBacks up: native or invasive status
- 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
- 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
- Invasive Plants in the District DC Department of Energy & EnvironmentBacks up: native or invasive status
- Virginia Invasive Plant Species List (effective date: September 2024) Virginia Department of Conservation and Recreation, Division of Natural HeritageBacks up: native or invasive status, safety details
- Gelsemium sempervirens (Carolina Jessamine) NC State Extension Gardener Plant ToolboxBacks up: safety
- Invasive Alien Plant Species of Virginia: Japanese Honeysuckle Virginia Department of Conservation and RecreationBacks up: safety details
- Non-Native Invasive Plant Species Control Treatments (Forestry Topic 31, Oct. 2018) Virginia Department of ForestryBacks up: safety details
- Integrated Pest Management Program Montgomery Parks (M-NCPPC)Backs up: safety details
- Research-grade observations of Japanese honeysuckle (Lonicera japonica) within 25 km of DC, by month (flowering) iNaturalistBacks up: season
- Research-grade observations of Japanese honeysuckle (Lonicera japonica) within 25 km of DC, by month (flower budding) iNaturalistBacks up: season
- Japanese Honeysuckle University of Maryland ExtensionBacks up: season, description, habitat, picking rules
- Lonicera japonica (Fire Effects Information System species review) USDA Forest ServiceBacks up: season, habitat
- Japanese Honeysuckle (field guide) Missouri Department of ConservationBacks up: season, habitat, picking rules, description