Groundnut is a perennial grown for its purple blooms, which open in summer and return year after year. It's hardy across USDA zones 3 through 7, shrugs off deer and grows just as well in a container as in the ground. Its summer flowers are a moderate draw for native bees and butterflies. A nitrogen-fixer, it draws nitrogen from the air and feeds it back to the soil — turn it under or leave the roots in place, and the next planting inherits a richer bed.
Groundnut — the short answer
Groundnut: grown in zones 3–7, part sun, pH 5.5–7.5.
- USDA zones
- 3–7
- 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
- Soil pH
- 5.5–7.5
- Growable Ground Plant Database
- Sun
- Part Sun
- Growable Ground Plant Database
- Frost-kill temperature
- 28°F
- Growable Ground Plant Database
Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — each tile names its own row's source, because per-field provenance varies.
Score Groundnut on your exact land.
Zone averages can't see the slope, soil, frost, and sun that decide whether groundnut actually takes — and those shift from one yard to the next. Enter your address and we'll score groundnut against your land's real conditions.
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What Groundnut is
Groundnut grows as a perennial and reaches around ten feet at maturity. It blooms purple in summer. It's also deer-resistant and well suited to containers.
How to grow Groundnut
Groundnut grows in USDA zones 3 through 7. Groundnut does best in part sun — at least 4 hours of direct sun a day — and soil from pH 5.5 to 7.5, on well-drained ground. It needs around 1,000 growing degree days to mature and a growing season of at least 120 frost-free days, which is why climate matters as much as soil.
USDA Zones
3-7
USDA PHZM 2023
Soil pH
5.5 - 7.5
Growable Ground Plant Database
Sun
Part Sun
Growable Ground plant catalog
Drainage
well (dry spells)
Growable Ground plant catalog
Frost Kill Temperature
28°F
Where cold starts killing growing tissue. Not a winter-survival floor — a dormant perennial takes far colder, which its hardiness zone answers.
Growable Ground Plant Database
GDD Required
1000+
Growing degree-days of accumulated warmth it needs to mature — humid summers reach this faster than cool coastal ones.
Growable Ground plant catalog
Mature Height
10 ft
Growable Ground plant catalog
Frost-Free Days
120+
The frost-free stretch it needs start to finish — short-season areas may need an indoor head start.
Growable Ground plant catalog
Start the season right
Plant groundnut in part sun with at least 4 hours of direct sun. It grows in the cool halves of the year, so sow it in spring or late summer rather than waiting for midsummer heat.
Match the soil
Groundnut prefers pH 5.5 to 7.5 (Growable Ground Plant Database). A quick soil test from your local Extension lab tells you whether to add lime or sulfur to land in band. It fixes its own nitrogen, so skip the high-nitrogen feed and instead dust the seed with a matching rhizobium inoculant at sowing.
Water steadily
Keep the root zone evenly moist through establishment. A 2–3 inch mulch layer holds moisture without waterlogging.
Harvest at its peak
Cut groundnut blooms in the cool of the morning, just as they open, for the longest display.
Where Groundnut thrives
Groundnut is hardy across USDA zones 3 through 7. Zone is only the starting point, though: the soil pH, drainage, and frost dates on your specific land decide how well it actually does.
A USDA zone is a 10°F band of average annual extreme winter minimum, so zones 3–7 spans average winter lows from -40°F to 10°F (USDA PHZM 2023). Across the 50 states and DC, that band covers 23 outright and splits 25 more down the middle — and which side of that line your land sits on changes the answer.
Zones 3–7·Where Groundnut growsOpen map →
Where Groundnut stands, state by state
Groundnut is rated for zones 3–7 — a cold floor USDA puts at -40 to -30°F. Across the 50 states and DC, 23 sit fully inside that band, the line runs through 25 more, and 3 sit outside it — and inside every split state, the same line runs on at county grain.
Fully inside zones 3–7
23 states
3 of 23 shown
The line runs through
25 states
- Alaska · zones 1a-9a
- Idaho · zones 3b-8a
- California · zones 4b-11a
3 of 25 shown
Groundnut’s band covers part of each of these states — which side of the line your county sits on changes the answer, and each state page draws it.
State zone extents: USDA Plant Hardiness Zone Map (PHZM) 2023. A zone is a 10°F band of average annual extreme minimum temperature, so a state that splits the band contains the boundary — its own page draws the county line, and a parcel report resolves which side your land sits on.
What grows around Groundnut
Growing guides for groundnut
In rotation planning, groundnut counts as a Legume — beds recover best when legume crops don’t follow each other in the same spot year over year. (Growable Ground derivation — crop-rotation group from botanical family)
Good to know
Good news for pet owners — groundnut isn't known to be toxic to dogs or cats. (Source: ASPCA.)
Groundnut offers moderate value to bees and other pollinators. (Source: Lady Bird Johnson Wildflower Center.)
Before you harvest groundnut, know your soil
Anything you grow to eat takes up what's in the ground it grows in, so it's worth knowing what's documented near you before you plant groundnut for food. Our free screen reads 9 federal source types across roughly 1.8M indexed sites and shows which sit near your address and which way they drain. It's a screening estimate from public records and proximity — not a soil test — so a nearby record means a soil test is worth it, not that your soil is unsafe.
Your land is one point inside Groundnut's range
This page resolves to the species. Your state page draws the county line, and a report reads the parcel — the soil pH, drainage, sun, and frost dates on your exact ground, which no species average can see.
See if Groundnut will thrive on your land
Zone averages are a start. Your exact soil pH, drainage, sun exposure, and frost dates shape whether groundnut actually takes — we score it against the real conditions at your address.
Three things about your exact spot that zone averages miss:
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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How we know this about Groundnut
The figures above are cited per row, not per site: the pH band names this plant’s own source column, the three temperature figures each carry their own, and days-to-maturity cites the publication that actually lists it. All of it comes from the Growable Ground Plant Database — a compilation over FAO ECOCROP, USDA PLANTS, and university Extension sources, published openly with per-field provenance.
Grounded inUSDA PLANTS Database•USDA PHZM•ASPCA
Frequently asked questions
Can I grow Groundnut in my zone?
Groundnut grows in USDA hardiness zones 3 through 7 (USDA PHZM 2023). Zone is one factor — soil pH, drainage, and frost dates on your specific parcel also shape whether it takes.
When should you plant Groundnut?
Groundnut is a cool-season crop, so it goes in during the cool halves of the year — early spring, and again in late summer for a fall planting — rather than at the height of summer heat. Your local frost dates set the exact window — a Growable Ground report reads them for your address.
How much sun does Groundnut need?
Groundnut does well in partial sun — around 4 hours of direct sun, and it takes some afternoon shade in stride. That flexibility makes it a good match for a bed the house or a nearby tree shades for part of the day. A Growable Ground report maps how the sun actually falls on your land, hour by hour, so you can set it where the light lines up.
What soil does Groundnut need?
Groundnut prefers soil pH 5.5 to 7.5, on well-drained ground (Growable Ground Plant Database). Your report scores your parcel's actual soil against that using USDA SSURGO data.
Does Groundnut attract pollinators?
Yes — groundnut's flowers are a solid nectar source for native bees and butterflies. (Source: Lady Bird Johnson Wildflower Center.)
Is Groundnut safe for pets?
Groundnut is not known to be toxic to dogs or cats based on available data. Always supervise pets around new plantings. (Source: ASPCA.)