mountain laurel (Kalmia latifolia), photographi

Can I Grow Mountain Laurel in Vermont?

USDA Zones 4a-6a · Plant zone range 5-11

Generally — Most Areas

mountain laurel (zones 5-11) suits most of Vermont (4a-6a) — zones 5-6 are in range, and the rest of the state is the exception.

Mountain Laurel in Vermont — the short answer

Mountain Laurel in Vermont: hardy in zones 5–11, shade, against a state median of ~163 frost-free days.

Plant zones
5-11
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
Vermont zones
4a-6a
USDA PHZM 2023
Frost window
Apr 27 - May 5 – Oct 10 - Oct 17
NOAA RCC ACIS 1991-2020, 28°F
Shortest county season
146 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.

Score your parcel · free

Your yard isn't the whole zone.

Vermont spans zones 4a-6a, 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 mountain laurel 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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Vermont is not one climate

Vermont’s winter-low ladder runs across 14 counties, from zone 4.5 in Caledonia County to zone 5.5 in Windsor County. That is 10°F between the two counties’ average coldest night — the difference between mountain laurel overwintering in the ground and coming under cover.

4.5 zonesCaledonia County5.5 zonesWindsor County

The middle half of 14 counties runs 4.55 zones, with a median of 5 zones — a 1-zone span end to end.

Measured across 14 Vermont 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 Vermont Fits Best

Mountain Laurel is rated for zones 511 — a cold floor USDA puts at -20 to -10°F. Against Vermont’s 14 counties that band holds in 9 of them, and the line runs at Addison County (zone 5a), the coldest county still inside it.

Inside zones 5–11

9 counties

3 of 9 shown

Below the zone 5 floor

5 counties

3 of 5 shown

Winter cold is the limit here — the same plant works in a container that comes under cover.

County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. A zone is a 10°F band of average annual extreme minimum temperature, so the floor above is the band the plant's rating denotes, not a single measured kill point. Slope, shelter and cold-air drainage routinely move a site half a zone either way from its county figure — which is the part only your address resolves.

Even within Vermont's zones 4a-6a, county microclimates differ enough to change what thrives. These counties carry the closest zone match for mountain laurel (USDA PHZM 2023):

Zone Comparison

Mountain Laurel Needs

  • USDA Zones: 5-11
  • Frost-Free Days: 150+
  • Sun: Shade
  • Mature size: 10 ft tall
  • Drought tolerance: High

Vermont Has

  • USDA Zones: 4a-6a
  • Last Hard Freeze (28°F): Apr 27 - May 5
  • First Hard Freeze (28°F): Oct 10 - Oct 17
  • Annual Rainfall: 34-44 inches
  • Common Soils: Glacial till, Clay, Silt loam

Plant Zone Range (zones 5-11)

5a
11b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 4.55.5

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 Mountain Laurel in Vermont

The frost window

Across Vermont, the last spring hard freeze (28°F) clears between Apr 27 and May 5, and the first fall hard freeze lands between Oct 10 and Oct 17 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 158-day window you can count on — up to 173 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

Vermont runs as cold as USDA zone 4, and no sourced winter-hardiness floor is on record for mountain laurel, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether mountain laurel is a permanent planting or a replant-every-spring crop for you turns on your own zone within Vermont; check its hardiness range against that before treating it as long-lived ground.

Timing tuned to sub-state frost dates — Essex 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 mountain laurel survives winter in part of Vermont, not across all of it. Whether the season is long enough — and warm enough — is a different question.

Frost-free days

Mountain Laurel wants 150+ frost-free days; a typical Vermont site sees ~163 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves a tight window — use transplants and pick early-maturing cultivars.

Chill hours

Mountain Laurel requires ~600 chill hours (32-45°F dormancy window). Vermont typically banks ~2500 chill hours per winter (from PRISM 1991-2020 climate normals), which keeps this plant on track.

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

Mountain Laurel prefers acidic soil (pH 4.5-5.5). Vermont's glacial till can run on the acidic side, which often aligns well — confirm with a soil test before planting.

Your land, not the state average

Vermont's soils run mostly fine sandy loam, but SSURGO maps the series, texture, and drainage under your exact parcel. What matters for mountain laurel is the horizon its roots actually work, not the surface. That map unit, not the state average, decides how mountain laurel performs.

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. Vermont soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.

What Else to Consider for Mountain Laurel in Vermont

Zone compatibility tells you about winter cold survival — but Vermont growers also need to think about:

Short growing season (100-130 frost-free days)

Rocky soils throughout the Green Mountains

Heavy clay in the Champlain Valley

Growing mountain laurel here specifically

Mountain Laurel needs pH 4.5–5.5; Vermont's dominant fine sandy loam soils may or may not deliver that, so your parcel's SSURGO map unit is the real test.

Start with a soil test on your own ground and adjust pH and texture to fit mountain laurel's 4.5–5.5 range. How to handle it →

What to actually do about these — and the constraints that apply to every Vermont grower, not just mountain laurel — is covered on the Vermont growing guide.

Timing shifts within Vermont

Vermont isn't one climate. In Essex County, the last hard freeze (28°F) holds until about May 13 — roughly 11 days later than the recorded state median — so plant mountain laurel to your county's window, not the statewide date.

Mountain Laurel needs about 150 days of frost-free season to complete its cycle. 13 of Vermont’s 14 counties give it that outright. The tightest that does is Caledonia County at 153 frost-free days — 3 to spare. Below that line you are transplanting or extending the season, not direct-sowing.

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"). Mountain Laurel's 150-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

Mountain Laurel draws native bees (moderate value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, mountain laurel can only work that bloom inside Vermont's frost window — roughly 163 days, opening after the last 28°F freeze (Apr 27 - May 5) and closing at the first (Oct 10 - Oct 17), per NOAA Regional Climate Centers ACIS, 1991-2020.

Good to Know Before You Plant Mountain Laurel

Mountain Laurel is listed as toxic to dogs, cats, horses (all) at a severe level (ASPCA). Most listed plants only cause brief upset — a raised bed or a fenced corner usually keeps curious pets clear.

Vermont Cooperative Extension

For Vermont-specific cultivar recommendations, planting calendars, and pest pressure for mountain laurel, the canonical source is UVM Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.

Is Mountain Laurel native to Vermont?

Yes — the USDA PLANTS Database (accessed 2026-07-01) documents Mountain Laurel as native to Vermont. Planting it supports the pollinators and wildlife that evolved alongside it.

Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.

Common Questions About Growing Mountain Laurel in Vermont

When can I plant Mountain Laurel in Vermont?

Vermont's last spring hard freeze (28°F) clears between Apr 27 and May 5, and the first fall hard freeze lands between Oct 10 and Oct 17 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for Mountain Laurel, so this page does not state whether it overwinters in Vermont 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 Mountain Laurel grown in across Vermont?

Vermont spans USDA hardiness zones 4a-6a (USDA ARS PHZM 2023). Mountain Laurel carries a range of zones 5-11, so the overlap zones are where outdoor growing is most reliable.

How many frost-free days does a typical Vermont site have?

A typical Vermont site sees ~163 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Mountain Laurel needs 150+ 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 Essex, the freeze-free season runs shorter than the state average, so verify your own county's window.

Is Mountain Laurel native to Vermont?

Yes — the USDA PLANTS Database (accessed 2026-07-01) documents Mountain Laurel as native to Vermont. Planting it supports the pollinators and wildlife that evolved alongside it.

How should I amend the soil for Mountain Laurel in Vermont?

Mountain Laurel prefers pH 4.5-5.5 (USDA PLANTS). Most Vermont soils run mildly acidic to neutral; many sites land near this band naturally, and a soil test plus targeted sulfur or organic amendment closes any gap.

Will Mountain Laurel actually grow on my specific land in Vermont?

State-level zone + climate data is a sketch. A Growable Ground parcel report scores mountain laurel against your address's exact soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.

Free Report

Check your specific parcel in Vermont

State-level data is a sketch. Your Growable Ground report scores mountain laurel against your parcel's exact soil, sun, drainage, and frost data — not zone averages.

Three things about your lot that Vermont mountain laurel averages can't show:

Your soil pHYour frost-free days — Vermont averages 163Your sun & shade

We read public map data around Vermont — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources read at your address, not the Vermont mountain laurel average

Explore More

Explore Vermont county by county

Vermont carries 14 counties with their own USDA zone — a sample of the growing pages for mountain laurel there:

Where else mountain laurel grows

Mountain Laurel's zone band crosses state lines — these are the states closest to Vermont 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 Vermont

Vermont has a growing page for 747 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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