Generally — Most Areas
woodland phlox (zones 4-10) suits most of Maine (3b-7a) — zones 4-7 are in range, and the rest of the state is the exception.
Woodland Phlox in Maine — the short answer
Woodland Phlox in Maine: hardy in zones 4–10, part sun, against a state median of ~182 frost-free days.
- Plant zones
- 4-10
- Manual horticultural correction (source not retained); NC State Extension and Missouri Botanical Garden, with the remaining rows from other published sources or Growable Ground compilation
- Maine zones
- 3b-7a
- USDA PHZM 2023
- Frost window
- Apr 16 - May 3 – Oct 10 - Oct 24
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 143 days
- NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze
Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — per-field provenance varies and is published with the dataset.
Your yard isn't the whole zone.
Maine spans zones 3b-7a, but your yard sits in exactly one — and slope, tree cover, and cold-air pockets nudge it further. Enter your address and we'll score woodland phlox against your parcel's actual hardiness, soil, and sun.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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Maine is not one climate
Maine’s winter-low ladder runs across 16 counties, from zone 4 in Aroostook County to zone 6 in Lincoln County. That is 20°F between the two counties’ average coldest night — the difference between woodland phlox overwintering in the ground and coming under cover.
The middle half of 16 counties runs 4.5–5.5 zones, with a median of 5.5 zones — a 2-zone span end to end.
Measured across 16 Maine counties. USDA PHZM 2023, per county. Quartiles are order statistics — every figure shown is a value a real county recorded, not an interpolation. Your own site sits somewhere inside this range; a parcel report resolves where.
Where in Maine Fits Best
Even within Maine's zones 3b-7a, county microclimates differ enough to change what thrives. These counties carry the closest zone match for woodland phlox (USDA PHZM 2023):
Zone Comparison
Woodland Phlox Needs
- USDA Zones: 4-10
- Frost-Free Days: 100+
- Sun: Part Sun
- Mature size: 1.3 ft tall
- Picking window: ~21 days of harvest
- Drought tolerance: Low
Maine Has
- USDA Zones: 3b-7a
- Last Hard Freeze (28°F): Apr 16 - May 3
- First Hard Freeze (28°F): Oct 10 - Oct 24
- Annual Rainfall: 36-50 inches
- Common Soils: Glacial till, Sandy loam, Rocky loam
Plant Zone Range (zones 4-10)
Preferred Soil pH
Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS, and university Extension sources — per-field provenance varies and is published with the dataset. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.
When to Plant Woodland Phlox in Maine
The frost window
Across Maine, the last spring hard freeze (28°F) clears between Apr 16 and May 3, and the first fall hard freeze lands between Oct 10 and Oct 24 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 160-day window you can count on — up to 191 days on a mild site in a kind year. That marks the hard freeze, not the last light frost, so tender transplants usually wait another 2-3 weeks.
Winter standing
Maine runs as cold as USDA zone 3, and no sourced winter-hardiness floor is on record for woodland phlox, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether woodland phlox is a permanent planting or a replant-every-spring crop for you turns on your own zone within Maine; check its hardiness range against that before treating it as long-lived ground.
Timing tuned to sub-state frost dates — Piscataquis County, not the statewide average.
Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: Growable Ground Plant Database — frost-free days from FAO ECOCROP, days to harvest from university Extension production guides, and growing-degree-day and chill-hour minimums that are compilation estimates rather than published figures. Your site's own frost dates can run earlier or later than the state range — a parcel report pins them down.
Growing Season Fit
The zone check says woodland phlox survives winter in part of Maine, not across all of it. Whether the season is long enough — and warm enough — is a different question.
Frost-free days
Woodland Phlox wants 100+ frost-free days; a typical Maine site sees ~182 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.
GDD and chill-hour figures are computed from PRISM 1991-2020 monthly climate normals; frost-free days from NOAA Regional Climate Centers ACIS, 1991-2020. Each is the state median across its counties (P25/P75 span the within-state spread). Hardiness-zone range is USDA PHZM 2023.
Soil + Drainage Fit
Woodland Phlox likes near-neutral soil (pH 5.5-7.2). That's the common-ground band across Maine's glacial till and sandy loam — a soil test confirms it for your site.
Your land, not the state average
SSURGO maps about 27.4% of Maine as poorly or somewhat-poorly drained, and the class flips parcel to parcel. Woodland Phlox has low drought tolerance, so it is the fast-draining end that will cost you — your soil map unit, not the state average, is the real answer.
Check your parcel → Source: USDA NRCS SSURGO.
Plant pH requirements: FAO ECOCROP and USDA PLANTS, with the remaining rows from other published sources or Growable Ground compilation. Drainage: FAO ECOCROP, with the remaining rows from other published sources or Growable Ground compilation. Maine soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
What Else to Consider for Woodland Phlox in Maine
Zone compatibility tells you about winter cold survival — but Maine growers also need to think about:
Very short growing season (100-140 frost-free days)
Rocky glacial soils require significant clearing
Harsh winters with heavy snow and ice
Growing woodland phlox here specifically
Woodland Phlox wilts without steady moisture and rates to zones 4–10; roughly 21.7% of Maine sits on sandy, excessively-drained ground (SSURGO) that sheds water almost as fast as it falls.
Hold moisture for woodland phlox with deep mulch and drip lines, especially on the droughtiest parcels. How to handle it →
What to actually do about these — and the constraints that apply to every Maine grower, not just woodland phlox — is covered on the Maine growing guide.
Timing shifts within Maine
Maine isn't one climate. In Piscataquis County, the last hard freeze (28°F) holds until about May 15 — roughly 23 days later than the recorded state median — so plant woodland phlox to your county's window, not the statewide date.
Woodland Phlox needs about 100 days of frost-free season to complete its cycle. Even Franklin County — Maine’s shortest season at 143 frost-free days — clears that by 43 days, so season length isn’t the constraint anywhere in Maine. What varies is your own parcel.
Across Maine’s 16 counties the frost-free season runs from 143 days in Franklin County to 222 days in Knox County — a spread of 79 days, which is why a single statewide planting date misleads. The median Maine county sees 182 frost-free days, leaving woodland phlox about 82 days of slack on a typical parcel — room for a second sowing where the season runs long.
County last-freeze dates and frost-free day counts: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). Woodland Phlox's 100-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.
Pollinator + Wildlife Value
Woodland Phlox draws native bees, butterflies, hummingbirds, and moths (high value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, woodland phlox can only work that bloom inside Maine's frost window — roughly 182 days, opening after the last 28°F freeze (Apr 16 - May 3) and closing at the first (Oct 10 - Oct 24), per NOAA Regional Climate Centers ACIS, 1991-2020.
Recommended Woodland Phlox Varieties for Maine
Maine publishes no state variety trial for woodland phlox, so we won't invent a "best for Maine" list. Choose types rated to your USDA hardiness zone (3b-7a), and confirm winter survival and drainage against your own parcel.
Maine Cooperative Extension
For Maine-specific cultivar recommendations, planting calendars, and pest pressure for woodland phlox, the canonical source is UMaine Cooperative Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Woodland Phlox native to Maine?
Woodland Phlox is native to parts of the Lower 48, but the USDA PLANTS Database (accessed 2026-07-01) does not document a native range in Maine. It can still earn a place in a Maine garden — the zone comparison above tells you whether it will thrive.
Looking for plants that belong here? The Maine growing guide lists USDA-documented natives for the state.
Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.
Common Questions About Growing Woodland Phlox in Maine
When can I plant Woodland Phlox in Maine?
Maine's last spring hard freeze (28°F) clears between Apr 16 and May 3, and the first fall hard freeze lands between Oct 10 and Oct 24 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for Woodland Phlox, so this page does not state whether it overwinters in Maine and publishes no fall establishment date for it — check its hardiness range against your own zone before treating it as a permanent planting.
What hardiness zone is Woodland Phlox grown in across Maine?
Maine spans USDA hardiness zones 3b-7a (USDA ARS PHZM 2023). Woodland Phlox carries a range of zones 4-10, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical Maine site have?
A typical Maine site sees ~182 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Woodland Phlox needs 100+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date. In cooler counties like Piscataquis, the freeze-free season runs shorter than the state average, so verify your own county's window.
Is Woodland Phlox native to Maine?
Woodland Phlox is native to parts of the Lower 48, but the USDA PLANTS Database (accessed 2026-07-01) does not document a native range in Maine. It can still earn a place in a Maine garden — the zone comparison above tells you whether it will thrive.
How should I amend the soil for Woodland Phlox in Maine?
Woodland Phlox prefers pH 5.5-7.2 (USDA PLANTS). That sits in the common-ground band across Maine soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.
Will Woodland Phlox actually grow on my specific land in Maine?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores woodland phlox against your address's exact soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.
Check your specific parcel in Maine
State-level data is a sketch. Your Growable Ground report scores woodland phlox against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Maine woodland phlox averages can't show:
We read public map data around Maine — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Maine woodland phlox average
Explore More
Growing guides for woodland phlox
Explore Maine county by county
Maine carries 16 counties with their own USDA zone — a sample of the growing pages for woodland phlox there:
Where else woodland phlox grows
Woodland Phlox's zone band crosses state lines — these are the states closest to Maine in winter climate where it also has a page, plus the far ends of its range. Each one re-answers the question with that state's own record.
More to grow in Maine
Maine has a growing page for 806 plants — a rotating sample of the rest of the shelf.
Analysis by the Growable Ground research team, grounded in USDA PLANTS, USDA NRCS SSURGO, NOAA Climate Normals (1991-2020), and named Cooperative Extension sources. How we know →
Cite this dataset
Kirchick, M. (2026). Growable Ground Plant Database [Data set]. Zenodo. https://doi.org/10.5281/zenodo.21435643
Licensed CC BY-NC 4.0. DOI 10.5281/zenodo.21435643
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