red tasselflower (Emilia sonchifolia), photographi

Can I Grow Red Tasselflower in Hawaii?

USDA Zones 8b-13a · Plant zone range 8-11

Yes — Strong Match

red tasselflower is grown as an annual, so season length decides it here, not a winter zone — and Hawaii's typical season runs ~365 frost-free days against the ~90 red tasselflower needs.

Red Tasselflower in Hawaii — the short answer

Red Tasselflower in Hawaii: grown in zones 8–11, full sun, against a state median of ~365 frost-free days.

Plant zones
Grown as an annual — see the growing season
Growing season, not a hardiness zone
Hawaii zones
8b-13a
USDA PHZM 2023
Killing freeze
None on record
NOAA RCC ACIS 1991-2020
Shortest county season
365 days
NOAA Regional Climate Centers ACIS station record, 1991-2020, county 28°F killing freeze

Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — per-field provenance varies and is published with the dataset.

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Your yard isn't the whole zone.

Red Tasselflower is grown as an annual, so your winter zone isn't the deciding factor — your frost-free window is. A typical Hawaii site runs ~365 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 red tasselflower against your land's actual frost dates, sun, and soil.

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

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Hawaii is not one climate

Hawaii’s winter-low ladder runs across 5 counties, from zone 9 in Hawaii County to zone 11.5 in Kalawao County. That is 25°F between the two counties’ average coldest night — the difference between red tasselflower overwintering in the ground and coming under cover.

9 zonesHawaii County11.5 zonesKalawao County

The middle half of 5 counties runs 10–11.5 zones, with a median of 10 zones — a 2.5-zone span end to end.

Measured across 5 Hawaii counties. USDA PHZM 2023, per county. Quartiles are order statistics — every figure shown is a value a real county recorded, not an interpolation. Your own site sits somewhere inside this range; a parcel report resolves where.

Zone Comparison

Red Tasselflower Needs

  • USDA Zones: 8-11
  • Frost-Free Days: 90+
  • Sun: Full Sun
  • Picking window: ~90 days of harvestWe haven't confirmed this against a published source yet.

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 8-11)

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

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 4.0 – 7.0

Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS, and university Extension sources — per-field provenance varies and is published with the dataset. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.

When to Plant Red Tasselflower 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.

Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: Growable Ground Plant Database — frost-free days from FAO ECOCROP, days to harvest from university Extension production guides, and growing-degree-day and chill-hour minimums that are compilation estimates rather than published figures. 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

Red Tasselflower wants 90+ frost-free days; a typical Hawaii site sees ~365 (NOAA Regional Climate Centers ACIS station record, 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 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

Red Tasselflower tolerates a wide pH range (pH 4-7) — 3 units, acid ground through alkaline — so soil acidity is rarely what limits it in Hawaii. A soil test is still worth having, but for what else it tells you about this site, not to clear this plant. It will grow across that whole span, but it does best between pH 4.5 and 6.5 — worth knowing before you decide whether a Hawaii soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Hawaii site is heavier clay or sits in a low spot, a raised bed lifts the roots above wet ground, or work in compost.

Plant pH requirements: FAO ECOCROP and USDA PLANTS, with the remaining rows from other published sources or Growable Ground compilation. Drainage: FAO ECOCROP, with the remaining rows from other published sources or Growable Ground compilation. Hawaii soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.

What Else to Consider for Red Tasselflower in Hawaii

The zone range tells you where red tasselflower is grown — 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 red tasselflower — is covered on the Hawaii growing guide.

Timing shifts within Hawaii

Red Tasselflower needs about 90 days of frost-free season to complete its cycle. Even Hawaii County — Hawaii’s shortest season at 365 frost-free days — clears that by 275 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"). Red Tasselflower's 90-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

Red Tasselflower draws honeybees and native bees (low value). Planting it near vegetable beds can lift fruit set on neighboring crops. Red Tasselflower'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. Pollinator value: We haven't confirmed this against a published source yet.

Hawaii Cooperative Extension

For Hawaii-specific cultivar recommendations, planting calendars, and pest pressure for red tasselflower, the canonical source is UH Mānoa CTAHR Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.

Is Red Tasselflower native to Hawaii?

No — the USDA PLANTS Database lists Red Tasselflower as introduced rather than native in the Lower 48, so it is not part of Hawaii's native flora. It grows here as a garden plant; pairing it with a few Hawaii natives keeps local pollinators fed too.

Looking for plants that belong here? The Hawaii growing guide lists plants that USDA PLANTS records growing in Hawaii and that Kew and NatureServe Explorer both list in its native range, leaving out any that NatureServe flags as exotic there or that our audit holds.

State records: USDA PLANTS Database state-distribution data (presence, not state-level nativity), accessed 2026-10-19.

Common Questions About Growing Red Tasselflower in Hawaii

When can I plant Red Tasselflower 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 Red Tasselflower grown in across Hawaii?

Hawaii spans USDA hardiness zones 8b-13a (USDA ARS PHZM 2023). Red Tasselflower 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 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). Red Tasselflower needs 90+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.

Is Red Tasselflower native to Hawaii?

No — the USDA PLANTS Database lists Red Tasselflower as introduced rather than native in the Lower 48, so it is not part of Hawaii's native flora. It grows here as a garden plant; pairing it with a few Hawaii natives keeps local pollinators fed too.

How should I amend the soil for Red Tasselflower in Hawaii?

Red Tasselflower tolerates pH 4-7 and well (dry spells) drainage (FAO ECOCROP). That is a 3-unit span, acid ground through alkaline, so pH is rarely what limits this plant on a Hawaii site — amend for drainage and organic matter first.

Will Red Tasselflower actually grow on my specific land in Hawaii?

State-level zone + climate data is a sketch. A Growable Ground parcel report scores red tasselflower against your address's mapped soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.

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Check your specific parcel in Hawaii

State-level data is a sketch. Your Growable Ground report scores red tasselflower against your land's mapped soil, modelled sun, drainage, and frost data — not zone averages.

Three things about your lot that Hawaii red tasselflower averages can't show:

Your soil pHYour frost-free days — Hawaii averages 365Your sun & shade

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 red tasselflower average

Explore More

Explore Hawaii county by county

Hawaii carries 5 counties with their own USDA zone — a sample of the growing pages for red tasselflower there:

Where else red tasselflower grows

Red Tasselflower's zone band crosses state lines — these are the states closest to Hawaii in winter climate where it also has a page, plus the far ends of its range. Each one re-answers the question with that state's own record.

More to grow in Hawaii

Hawaii has a growing page for 789 plants — a rotating sample of the rest of the shelf.

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