Unlikely — Zone Mismatch
crowfoot grass (zones 8-12) does not overlap with New Hampshire's zone range (3b-6b). Growing outdoors is unlikely without significant protection.
2 zones short — what would close it
Crowfoot Grass is hardy to zone 8, and the warmest ground in New Hampshire is zone 6 — 2 zones short. Planted in open ground it will not survive a New Hampshire winter. To grow it here, grow crowfoot grass under glass — a greenhouse is the only lift this wide the engine models.
A greenhouse is the lift this needs. How a greenhouse changes what you can grow →
Zone math from 8-12 (plant) against 3-6 (New Hampshire). Lift modeled by crop_engine Sprint 20B effective_zone_modifier (+2 zones) via api/fast_sections.py Unlock Engine v2.
Your yard isn't the whole zone.
Crowfoot Grass is grown as an annual, so your winter zone isn't the deciding factor — your frost-free window is. A typical New Hampshire site runs ~171 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 crowfoot grass against your land's actual frost dates, sun, and soil.
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Zone Comparison
Crowfoot Grass Needs
- USDA Zones: 8-12
- Frost-Free Days: 90+
- Sun: Full Sun
New Hampshire Has
- USDA Zones: 3b-6b
- Last Hard Freeze (28°F): Apr 22 - May 4
- First Hard Freeze (28°F): Oct 10 - Oct 21
- Annual Rainfall: 36-50 inches
- Common Soils: Glacial till, Sandy loam, Rocky loam
Plant Zone Range (zones 8-12)
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 Crowfoot Grass in New Hampshire
The frost window
Across New Hampshire, the last spring hard freeze (28°F) clears between Apr 22 and May 4, and the first fall hard freeze lands between Oct 10 and Oct 21 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 159-day window you can count on — up to 182 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.
Frost tenderness
Crowfoot Grass is frost-tender — its listed minimum temperature is 50°F (USDA PLANTS Database) — so set plants out two to three weeks PAST your local last hard freeze, not on it and not on the state's earliest date. The 28°F marker above is when killing freezes stop, not when light frost does.
When to start the seed
Crowfoot Grass is direct-sown where it grows rather than started under cover, so there is no seed-tray head start to bank — New Hampshire's dates above are the whole calendar for it. That makes the last-freeze date the binding constraint, and a warmer pocket of your own yard is worth more to this crop than it is to a transplanted one.
Timing tuned to sub-state frost dates — Coos 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
The zone check says crowfoot grass does not survive a New Hampshire winter in the ground. The season figures below measure a different question — whether it could finish a season here at all — and they only bear on New Hampshire under protection.
Frost-free days
Crowfoot Grass wants 90+ frost-free days; a typical New Hampshire site sees ~171 (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
Crowfoot Grass likes near-neutral soil (pH 6-8.3). That's the common-ground band across New Hampshire's glacial till and sandy loam — a soil test confirms it for your site. It will grow across that whole span, but it does best between pH 6.5 and 7.5 — worth knowing before you decide whether a New Hampshire soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your New Hampshire site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
Your land, not the state average
New Hampshire's soils run mostly fine sandy loam, but SSURGO maps the series, texture, and drainage under your exact parcel. Crowfoot Grass needs about 7 inches of workable depth, so it is that horizon — not the surface — you are testing for. That map unit, not the state average, decides how crowfoot grass performs.
Check your parcel → Source: USDA NRCS SSURGO.
Plant pH and drainage requirements from USDA PLANTS Database. New Hampshire soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
Crowfoot Grass in New Hampshire — Quick Answer
- Verdict: Unlikely — Zone Mismatch
- Plant Zones: 8-12 (USDA PLANTS Database)
- State Zones: 3b-6b (USDA ARS PHZM 2023)
- Growing Season: 28°F hard freezes about Apr 22 - May 4 to Oct 10 - Oct 21 (NOAA Regional Climate Centers ACIS, 1991-2020)
What Else to Consider for Crowfoot Grass in New Hampshire
Zone compatibility tells you about winter cold survival — but New Hampshire growers also need to think about:
Very short season in the White Mountains (80-100 frost-free days)
Rocky glacial soils throughout the state
Harsh winters with deep snow cover
Growing crowfoot grass here specifically
New Hampshire's soils run mostly fine sandy loam (Spodosols), and whether that suits crowfoot grass's pH 6.0–8.3 preference comes down to your exact parcel, not the statewide picture.
Pull your parcel's SSURGO map unit, test pH, and amend toward crowfoot grass's 6.0–8.3 target before planting. How to handle it →
What to actually do about these — and the constraints that apply to every New Hampshire grower, not just crowfoot grass — is covered on the New Hampshire growing guide.
Timing shifts within New Hampshire
New Hampshire isn't one climate. In Coos County, the last hard freeze (28°F) holds until about May 13 — roughly 16 days later than the recorded state median — so plant crowfoot grass to your county's window, not the statewide date.
Crowfoot Grass needs about 90 days of frost-free season to complete its cycle. Even Coos County — New Hampshire’s shortest season at 145 frost-free days — clears that by 55 days, so season length isn’t the constraint anywhere in New Hampshire. 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"). Crowfoot Grass's 90-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.
New Hampshire Cooperative Extension
For New Hampshire-specific cultivar recommendations, planting calendars, and pest pressure for crowfoot grass, the canonical source is UNH Cooperative Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Crowfoot Grass native to New Hampshire?
No — the USDA PLANTS Database lists Crowfoot Grass as introduced rather than native in the Lower 48, so it is not part of New Hampshire's native flora. It grows here as a garden plant; pairing it with a few New Hampshire natives keeps local pollinators fed too.
Looking for plants that belong here? The New Hampshire 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 Crowfoot Grass in New Hampshire
When can I plant Crowfoot Grass in New Hampshire?
New Hampshire's last spring hard freeze (28°F) clears between Apr 22 and May 4, and the first fall hard freeze lands between Oct 10 and Oct 21 (NOAA Regional Climate Centers ACIS, 1991-2020). Crowfoot Grass is frost-tender — its listed minimum temperature is 50°F (USDA PLANTS Database) — so wait two to three weeks past your site's last hard freeze, when light frost has also stopped, before planting out.
What hardiness zone is Crowfoot Grass grown in across New Hampshire?
New Hampshire spans USDA hardiness zones 3b-6b (USDA ARS PHZM 2023). Crowfoot Grass carries a range of zones 8-12, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical New Hampshire site have?
A typical New Hampshire site sees ~171 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Crowfoot Grass needs 90+ 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 Coos, the freeze-free season runs shorter than the state average, so verify your own county's window.
Is Crowfoot Grass native to New Hampshire?
No — the USDA PLANTS Database lists Crowfoot Grass as introduced rather than native in the Lower 48, so it is not part of New Hampshire's native flora. It grows here as a garden plant; pairing it with a few New Hampshire natives keeps local pollinators fed too.
How should I amend the soil for Crowfoot Grass in New Hampshire?
Crowfoot Grass prefers pH 6-8.3 and well (dry spells) drainage (FAO ECOCROP). That sits in the common-ground band across New Hampshire soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.
Will Crowfoot Grass actually grow on my specific land in New Hampshire?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores crowfoot grass 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 New Hampshire
State-level data is a sketch. Your Growable Ground report scores crowfoot grass against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that New Hampshire crowfoot grass averages can't show:
We read public map data around New Hampshire — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the New Hampshire crowfoot grass average
Explore More
Growing guides for crowfoot grass
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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