Generally — Most Areas
chrysanthemum (zones 5-9) suits most of California (4b-11a) — zones 5-9 are in range, and the rest of the state is the exception.
Chrysanthemum in California — the short answer
Chrysanthemum in California: hardy in zones 5–9, full sun, against a state median of ~317 frost-free days.
- Plant zones
- 5-9
- 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
- California zones
- 4b-11a
- USDA PHZM 2023
- Frost window
- Jan 19 - Mar 19 – Nov 29 - Dec 12
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 108 days
- NOAA Regional Climate Centers ACIS, 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.
Your yard isn't the whole zone.
California spans zones 4b-11a, 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 chrysanthemum 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.
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California is not one climate
A single California answer averages 57 counties whose growing seasons are 257 days apart — from 108 frost-free days in Mono County to 365 in Ventura County. Which end of that your land sits nearer changes what chrysanthemum can finish before the first hard freeze.
The middle half of 57 counties runs 278–331 days, with a median of 317 days — a 257-day span end to end.
Measured across 57 California counties. NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze. 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.
Where in California Fits Best
Chrysanthemum is rated for zones 5–9 — a cold floor USDA puts at -20 to -10°F. Against California’s 58 counties that band holds in 28 of them, and the line runs at Mono County (zone 6a), the coldest county still inside it.
Inside zones 5–9
28 counties
- Alpine County · zone 6b
- Lassen County · zone 7a
- Modoc County · zone 7a
3 of 28 shown
Above the zone 9 ceiling
30 counties
- Alameda County · zone 9b
- Butte County · zone 9b
- Colusa County · zone 9b
3 of 30 shown
Too little winter chill rather than too much cold — a low-chill selection is what changes it.
County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. A zone is a 10°F band of average annual extreme minimum temperature, so the floor above is the band the plant's rating denotes, not a single measured kill point. Slope, shelter and cold-air drainage routinely move a site half a zone either way from its county figure — which is the part only your address resolves.
Even within California's zones 4b-11a, county microclimates differ enough to change what thrives. These counties carry the closest zone match for chrysanthemum (USDA PHZM 2023):
Zone Comparison
Chrysanthemum Needs
- USDA Zones: 5-9
- Frost-Free Days: 180+
- Sun: Full Sun
- Mature size: 3 ft tall
- Picking window: ~45 days of harvest
- Drought tolerance: Medium
California Has
- USDA Zones: 4b-11a
- Last Hard Freeze (28°F): Jan 19 - Mar 19
- First Hard Freeze (28°F): Nov 29 - Dec 12
- Annual Rainfall: 5-80 inches
- Common Soils: Alluvial clay, Sandy loam, Adobe clay
Plant Zone Range (zones 5-9)
Preferred Soil pH
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 Chrysanthemum in California
The frost window
Across California, the last spring hard freeze (28°F) clears between Jan 19 and Mar 19, and the first fall hard freeze lands between Nov 29 and Dec 12 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 255-day window you can count on — up to 327 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.
When to start the seed
Those dates are when chrysanthemum goes out, not when it starts. It is sown under cover about 8 weeks ahead, so counting back from California's late-side last freeze of Mar 19 is what fixes your sowing date — and a yard that clears frost earlier than the state's late date starts earlier still.
Timing tuned to sub-state frost dates — Mono County, not the statewide average.
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
The zone check says chrysanthemum survives winter in part of California, not across all of it. Whether the season is long enough — and warm enough — is a different question.
Frost-free days
Chrysanthemum wants 180+ frost-free days; a typical California site sees ~317 (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
Chrysanthemum likes near-neutral soil (pH 5.5-7.3). That's the common-ground band across California's alluvial clay 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 and 6.5 — worth knowing before you decide whether a California soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your California site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
Your land, not the state average
California's soils run mostly loam, but SSURGO maps the series, texture, and drainage under your exact parcel. Chrysanthemum 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 chrysanthemum performs.
Check your parcel → Source: USDA NRCS SSURGO.
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. California soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
What Else to Consider for Chrysanthemum in California
Zone compatibility tells you about winter cold survival — but California growers also need to think about:
Drought is a persistent challenge — irrigation is essential in most regions
Wildfire risk affects rural and foothill properties
Adobe clay soils in valleys drain poorly without amendment
Wide climate variation means plant selection is highly location-specific
Growing chrysanthemum here specifically
Chrysanthemum needs pH 5.5–7.3; California's dominant loam soils may or may not deliver that, so your parcel's SSURGO map unit is the real test.
Start with a soil test on your own ground and adjust pH and texture to fit chrysanthemum's 5.5–7.3 range. How to handle it →
What to actually do about these — and the constraints that apply to every California grower, not just chrysanthemum — is covered on the California growing guide.
Timing shifts within California
California isn't one climate. In Mono County, the last hard freeze (28°F) holds until about Jun 4 — roughly 120 days later than the recorded state median — so plant chrysanthemum to your county's window, not the statewide date.
Chrysanthemum needs about 180 days of frost-free season to complete its cycle. 51 of California’s 57 counties give it that outright. The tightest that does is Tuolumne County at 183 frost-free days — 3 to spare. Below that line you are transplanting or extending the season, not direct-sowing.
Across California’s 57 counties the frost-free season runs from 108 days in Mono County to 365 days in Ventura County — a spread of 257 days, which is why a single statewide planting date misleads. The median California county sees 317 frost-free days, leaving chrysanthemum about 137 days of slack on a typical parcel — room for a second sowing where the season runs long.
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"). Chrysanthemum'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
Chrysanthemum draws honeybees and butterflies (moderate value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, chrysanthemum can only work that bloom inside California's frost window — roughly 317 days, opening after the last 28°F freeze (Jan 19 - Mar 19) and closing at the first (Nov 29 - Dec 12), per NOAA Regional Climate Centers ACIS, 1991-2020.
Good to Know Before You Plant Chrysanthemum
Chrysanthemum is listed as toxic to dogs, cats (all) at a mild level (ASPCA). Most listed plants only cause brief upset — a raised bed or a fenced corner usually keeps curious pets clear. Worth knowing for placement: in California this is a one-season plant and the first hard freeze (Nov 29 - Dec 12) takes it down, so the exposure above is a summer-long one rather than something standing in the bed all year.
Recommended Chrysanthemum Varieties for California
California publishes no state variety trial for chrysanthemum, so we won't invent a "best for California" list. Choose types rated to your USDA hardiness zone (4b-11a), and confirm winter survival and drainage against your own parcel.
California Cooperative Extension
For California-specific cultivar recommendations, planting calendars, and pest pressure for chrysanthemum, the canonical source is UC Agriculture and Natural Resources. Their fact sheets carry the local trial data we can't generalize across 50 states.
Common Questions About Growing Chrysanthemum in California
When can I plant Chrysanthemum in California?
California's last spring hard freeze (28°F) clears between Jan 19 and Mar 19, and the first fall hard freeze lands between Nov 29 and Dec 12 (NOAA Regional Climate Centers ACIS, 1991-2020). Time outdoor planting to after the last hard freeze for your specific site — a further two to three weeks for anything tender — and count back from those dates for transplant scheduling.
What hardiness zone is Chrysanthemum grown in across California?
California spans USDA hardiness zones 4b-11a (USDA ARS PHZM 2023). Chrysanthemum carries a range of zones 5-9, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical California site have?
A typical California site sees ~317 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Chrysanthemum 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 Mono, the freeze-free season runs shorter than the state average, so verify your own county's window.
How should I amend the soil for Chrysanthemum in California?
Chrysanthemum prefers pH 5.5-7.3 and well (dry spells) drainage (FAO ECOCROP). That sits in the common-ground band across California soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.
Will Chrysanthemum actually grow on my specific land in California?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores chrysanthemum 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 California
State-level data is a sketch. Your Growable Ground report scores chrysanthemum against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that California chrysanthemum averages can't show:
We read public map data around California — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the California chrysanthemum average
Explore More
Growing guides for chrysanthemum
Explore California county by county
California carries 58 counties with their own USDA zone — a sample of the growing pages for chrysanthemum there:
Where else chrysanthemum grows
Chrysanthemum's zone band crosses state lines — these are the states closest to California 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 California
California has a growing page for 1,046 plants — a rotating sample of the rest of the shelf.
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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