Conditional — Some Areas
geranium (zones 10-11) reaches only part of Hawaii (8b-13a): zones 10-11 are in range, so where you are in the state decides it.
Your yard isn't the whole zone.
Hawaii spans zones 8b-13a, but your yard has its own microclimate — slope, trees, and low spots shift frost and sun across a single parcel. Enter your address and we'll score geranium against your land's actual soil, sun, and frost.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
No card required · your full report in seconds
Zone Comparison
Geranium Needs
- USDA Zones: 10-11
- Sun: Part Sun
- Mature size: 1.5 ft tall
- Picking window: ~150 days of harvest
- Drought tolerance: Medium
Hawaii Has
- USDA Zones: 8b-13a
- Hard Freeze (28°F): None on record — year-round season
- Annual Rainfall: 10-400 inches
- Common Soils: Volcanic, Laterite, Coral sand
Plant Zone Range (zones 10-11)
Plant data: USDA PLANTS Database / Growable Ground plant catalog. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.
When to Plant Geranium in Hawaii
The frost window
Hawaii has none — the 1991-2020 station record carries no 28°F killing freeze, so there is no last-frost date to plant after and no first-frost date to harvest before (NOAA Regional Climate Centers ACIS station record). The growing season is year-round; what paces planting here is rainfall, heat and elevation, not the calendar.
Days to maturity vs. the window
At 95 days to maturity (USDA PLANTS Database) and no frost to close the season, geranium fits about 3 plantings a year — so the real limit is what you can keep watered and harvested, not how many days are left.
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 geranium survives winter in part of Hawaii, not across all of it. Whether the season is long enough — and warm enough — is a different question.
Days to maturity
Geranium matures in ~95 days (Growable Ground Plant Database). A typical Hawaii site has ~365 frost-free days, so plenty of room for a second succession.
GDD and chill-hour figures are computed from PRISM 1991-2020 monthly climate normals; frost-free days from NOAA Regional Climate Centers ACIS station record, 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
Drainage matters: this plant wants well (dry spells). If your Hawaii site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
Plant pH and drainage requirements from USDA PLANTS Database. Hawaii soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
Geranium in Hawaii — Quick Answer
- Verdict: Conditional — Some Areas
- Plant Zones: 10-11 (USDA PLANTS Database)
- State Zones: 8b-13a (USDA ARS PHZM 2023)
- Growing Season: year-round — no 28°F killing freeze in Hawaii’s 30-year station record (NOAA Regional Climate Centers ACIS, 1991-2020)
- Days to Maturity: 95 days
What Else to Consider for Geranium in Hawaii
Zone compatibility tells you about winter cold survival — but Hawaii growers also need to think about:
Extreme rainfall variation — desert on one side, rainforest on the other
Volcanic soil is nutrient-poor in young flows
Invasive species pressure is severe
What to actually do about these — and the constraints that apply to every Hawaii grower, not just geranium — is covered on the Hawaii growing guide.
Timing shifts within Hawaii
Geranium needs about 95 days of frost-free season from planting to harvest. Even Hawaii County — Hawaii’s shortest season at 365 frost-free days — clears that by 270 days, so season length isn’t the constraint anywhere in Hawaii. 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"). Geranium's 95-day requirement: USDA PLANTS / Growable Ground plant database (days to maturity). A parcel report resolves your address's own frost dates.
Pollinator + Wildlife Value
Geranium draws honeybees and butterflies (moderate value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Geranium's flowers are not fenced in by a freeze date here: the 1991-2020 record resolves no 28°F killing frost anywhere in Hawaii, so what limits bloom is the plant's own cycle rather than the calendar.
Hawaii Cooperative Extension
For Hawaii-specific cultivar recommendations, planting calendars, and pest pressure for geranium, the canonical source is UH Mānoa CTAHR Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.
Common Questions About Growing Geranium in Hawaii
When can I plant Geranium in Hawaii?
Any month — Hawaii records no 28°F killing freeze in the 1991-2020 station record, so there is no last-frost date to wait for and the growing season is year-round (NOAA Regional Climate Centers ACIS station record). Pace planting by rainfall, heat and elevation instead: the summit country does freeze, and no station up there carries a long enough record to date it.
What hardiness zone is Geranium grown in across Hawaii?
Hawaii spans USDA hardiness zones 8b-13a (USDA ARS PHZM 2023). Geranium carries a range of zones 10-11, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical Hawaii site have?
A typical Hawaii site sees ~365 frost-free days per year (derived from NOAA Regional Climate Centers ACIS station record, 1991-2020). Geranium should be matched against that window, so check whether your local microclimate runs above or below the state average before settling on a planting date.
Will Geranium actually grow on my specific land in Hawaii?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores geranium 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 Hawaii
State-level data is a sketch. Your Growable Ground report scores geranium against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Hawaii geranium averages can't show:
We read public map data around Hawaii — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Hawaii geranium average
Explore More
Growing guides for geranium
Last updated: