Can I Grow Silverleaf Desmodium in New Hampshire?

USDA Zones 3b-6b · Plant zone range 8-11

Unlikely — Zone Mismatch

silverleaf desmodium (zones 8-11) 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

Silverleaf Desmodium 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 silverleaf desmodium 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 8-11 (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.

Score your parcel · free

Your yard isn't the whole zone.

New Hampshire spans zones 3b-6b, 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 silverleaf desmodium against your parcel's actual hardiness, soil, and sun.

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Zone Comparison

Silverleaf Desmodium Needs

  • USDA Zones: 8-11
  • Frost-Free Days: 180+
  • Sun: Full Sun
  • Mature size: 3 ft tall
  • Drought tolerance: Medium

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 8-11)

8a
11b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 5.07.0

Plant data: USDA PLANTS Database / Growable Ground plant catalog. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.

When to Plant Silverleaf Desmodium 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.

Winter standing

New Hampshire runs as cold as USDA zone 3, and no sourced winter-hardiness floor is on record for silverleaf desmodium, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether silverleaf desmodium is a permanent planting or a replant-every-spring crop for you turns on your own zone within New Hampshire; check its hardiness range against that before treating it as long-lived ground.

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 silverleaf desmodium 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

Silverleaf Desmodium wants 180+ frost-free days; a typical New Hampshire site sees ~171 (NOAA Regional Climate Centers ACIS, 1991-2020) — 9 days short of what it needs. A typical New Hampshire season does not carry this crop to harvest outdoors, and a gap that size is not one an earlier sowing date or a faster cultivar closes; growing it here means growing it under cover.

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

Silverleaf Desmodium likes near-neutral soil (pH 5-7). 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 5.5 and 6.5 — 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. Silverleaf Desmodium needs about 19 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 silverleaf desmodium 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.

Silverleaf Desmodium in New Hampshire — Quick Answer

  • Verdict: Unlikely — Zone Mismatch
  • Plant Zones: 8-11 (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 Silverleaf Desmodium 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 silverleaf desmodium here specifically

New Hampshire's soils run mostly fine sandy loam (Spodosols), and whether that suits silverleaf desmodium's pH 5.0–7.0 preference comes down to your exact parcel, not the statewide picture.

Pull your parcel's SSURGO map unit, test pH, and amend toward silverleaf desmodium's 5.0–7.0 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 silverleaf desmodium — 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 silverleaf desmodium to your county's window, not the statewide date.

Silverleaf Desmodium needs about 180 days of frost-free season to complete its cycle. 3 of New Hampshire’s 10 counties give it that outright. The tightest that does is Hillsborough County at 183 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"). Silverleaf Desmodium's 180-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

Silverleaf Desmodium 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, silverleaf desmodium can only work that bloom inside New Hampshire's frost window — roughly 171 days, opening after the last 28°F freeze (Apr 22 - May 4) and closing at the first (Oct 10 - Oct 21), per NOAA Regional Climate Centers ACIS, 1991-2020.

New Hampshire Cooperative Extension

For New Hampshire-specific cultivar recommendations, planting calendars, and pest pressure for silverleaf desmodium, the canonical source is UNH Cooperative Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.

Is Silverleaf Desmodium native to New Hampshire?

No — the USDA PLANTS Database lists Silverleaf Desmodium 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 Silverleaf Desmodium in New Hampshire

When can I plant Silverleaf Desmodium 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). No sourced winter-hardiness floor is on record for Silverleaf Desmodium, so this page does not state whether it overwinters in New Hampshire 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 Silverleaf Desmodium grown in across New Hampshire?

New Hampshire spans USDA hardiness zones 3b-6b (USDA ARS PHZM 2023). Silverleaf Desmodium carries a range of zones 8-11, 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). Silverleaf Desmodium needs 180+ 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 Silverleaf Desmodium native to New Hampshire?

No — the USDA PLANTS Database lists Silverleaf Desmodium 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 Silverleaf Desmodium in New Hampshire?

Silverleaf Desmodium prefers pH 5-7 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 Silverleaf Desmodium actually grow on my specific land in New Hampshire?

State-level zone + climate data is a sketch. A Growable Ground parcel report scores silverleaf desmodium 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 New Hampshire

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

Three things about your lot that New Hampshire silverleaf desmodium averages can't show:

Your soil pHYour frost-free days — New Hampshire averages 171Your sun & shade

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 silverleaf desmodium 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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