Yes — Strong Match
strawflower is grown as an annual, so season length decides it here, not a winter zone — and Vermont's typical season runs ~163 frost-free days against the ~60 strawflower needs.
Sow by about Jul 24
Strawflower is grown as an annual, so what decides it here is season length, not a winter zone. It needs about 60 frost-free days and a typical Vermont season runs ~163 frost-free days, leaving 103 days of slack. That is room to sow as late as about Jul 24 and still finish before the usual first freeze (Oct 12).
Want more weeks at either end of that window? How to buy the weeks →
60 frost-free days required against Vermont’s ~163-day season. NOAA Regional Climate Centers ACIS 1991-2020 (28°F killing freeze), state median across counties, via stateClimateData.ts.
Your yard isn't the whole zone.
Strawflower is grown as an annual, so your winter zone isn't the deciding factor — your frost-free window is. A typical Vermont site runs ~163 frost-free days, but that is a state median, not your yard: slope, trees, and low spots move the last-frost date across a single parcel. Enter your address and we'll score strawflower against your land's actual frost dates, sun, and soil.
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Zone Comparison
Strawflower Needs
- USDA Zones: Data pending
- Frost-Free Days: 60+
- Sun: Full Sun
- Mature size: 3 ft tall
- Picking window: ~90 days of harvest
- 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
Preferred Soil pH
Plant data: USDA PLANTS Database / Growable Ground plant catalog. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.
When to Plant Strawflower 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.
When to start the seed
Those dates are when strawflower goes out, not when it starts. It is sown under cover about 6 weeks ahead, so counting back from Vermont's late-side last freeze of May 5 is what fixes your sowing date — and a yard that clears frost earlier than the state's late date starts earlier still.
Days to maturity vs. the window
At 80 days to maturity (USDA PLANTS Database), counting from the last hard freeze it ripens with 78 days to spare even in Vermont's tightest freeze scenario — room for a later start or a second sowing.
Timing tuned to sub-state frost dates — Essex County, not the statewide average.
Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: USDA PLANTS Database. Your site's own frost dates can run earlier or later than the state range — a parcel report pins them down.
Growing Season Fit
Frost-free days
Strawflower wants 60+ frost-free days; a typical Vermont site sees ~163 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.
Growing degree days
Strawflower needs ~900 GDD (base 50°F) to ripen. The state median runs ~1746 GDD (from PRISM 1991-2020 climate normals), so Vermont's typical season clears that easily.
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
Strawflower likes near-neutral soil (pH 5.5-7). That's the common-ground band across Vermont's glacial till and clay — a soil test confirms it for your site. It will grow across that whole span, but it does best between pH 6 and 6.5 — worth knowing before you decide whether a Vermont soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Vermont site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
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 strawflower is the horizon its roots actually work, not the surface. That map unit, not the state average, decides how strawflower performs.
Check your parcel → Source: USDA NRCS SSURGO.
Plant pH and drainage requirements from USDA PLANTS Database. Vermont soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
Strawflower in Vermont — Quick Answer
- Verdict: Yes — Strong Match
- Plant Zones: Data pending (USDA PLANTS Database)
- State Zones: 4a-6a (USDA ARS PHZM 2023)
- Growing Season: 28°F hard freezes about Apr 27 - May 5 to Oct 10 - Oct 17 (NOAA Regional Climate Centers ACIS, 1991-2020)
- Days to Maturity: 80 days
What Else to Consider for Strawflower 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 strawflower here specifically
Vermont's soils run mostly fine sandy loam (Spodosols), and whether that suits strawflower's pH 5.5–7.0 preference comes down to your exact parcel, not the statewide picture.
Pull your parcel's SSURGO map unit, test pH, and amend toward strawflower's 5.5–7.0 target before planting. How to handle it →
What to actually do about these — and the constraints that apply to every Vermont grower, not just strawflower — 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 strawflower to your county's window, not the statewide date.
Strawflower needs about 60 days of frost-free season to complete its cycle. Even Essex County — Vermont’s shortest season at 146 frost-free days — clears that by 86 days, so season length isn’t the constraint anywhere in Vermont. What varies is your own parcel.
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"). Strawflower's 60-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
Strawflower draws honeybees, native bees, and butterflies (moderate value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, strawflower 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.
Recommended Strawflower Varieties for Vermont
Vermont publishes no state variety trial for strawflower, so we won't invent a "best for Vermont" list. Choose types rated to your USDA hardiness zone (4a-6a), and confirm winter survival and drainage against your own parcel.
Vermont Cooperative Extension
For Vermont-specific cultivar recommendations, planting calendars, and pest pressure for strawflower, the canonical source is UVM Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Strawflower native to Vermont?
No — the USDA PLANTS Database lists Strawflower as introduced rather than native in the Lower 48, so it is not part of Vermont's native flora. It grows here as a garden plant; pairing it with a few Vermont natives keeps local pollinators fed too.
Looking for plants that belong here? The Vermont 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 Strawflower in Vermont
When can I plant Strawflower 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). Time outdoor planting to after the last hard freeze for your specific site — a further two to three weeks for anything tender — and count back from those dates for transplant scheduling.
Can Strawflower mature before first frost in Vermont?
Yes — Strawflower matures in 80 days (USDA PLANTS Database), and Vermont's dependable hard-freeze-free window runs 158 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 78 days of margin. Plant once the last hard freeze has passed — two to three weeks later for anything tender — and it ripens ahead of the first fall freeze.
What hardiness zone is Strawflower grown in across Vermont?
Vermont spans USDA hardiness zones 4a-6a (USDA ARS PHZM 2023). Strawflower carries a range of zones Data pending, 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). Strawflower needs 60+ 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 Strawflower native to Vermont?
No — the USDA PLANTS Database lists Strawflower as introduced rather than native in the Lower 48, so it is not part of Vermont's native flora. It grows here as a garden plant; pairing it with a few Vermont natives keeps local pollinators fed too.
How should I amend the soil for Strawflower in Vermont?
Strawflower prefers pH 5.5-7 and well (dry spells) drainage (Growable Ground Plant Database). That sits in the common-ground band across Vermont soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.
Will Strawflower actually grow on my specific land in Vermont?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores strawflower 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 Vermont
State-level data is a sketch. Your Growable Ground report scores strawflower against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Vermont strawflower averages can't show:
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 strawflower average
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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