Yes — Strong Match
knockout rose (zones 5-11) covers every zone Louisiana contains (8b-10b), so hardiness is not what limits it anywhere in the state.
Your yard isn't the whole zone.
Louisiana spans zones 8b-10b, 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 knockout rose against your parcel's actual hardiness, soil, and sun.
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Zone Comparison
Knockout Rose Needs
- USDA Zones: 5-11
- Sun: Part Sun
- Mature size: 4 ft tall
- Picking window: ~28 days of harvest
- Drought tolerance: Medium
Louisiana Has
- USDA Zones: 8b-10b
- Last Hard Freeze (28°F): Jan 30 - Feb 17
- First Hard Freeze (28°F): Nov 30 - Dec 8
- Annual Rainfall: 50-65 inches
- Common Soils: Alluvial clay, Muck, Sandy loam
Plant Zone Range (zones 5-11)
Plant data: USDA PLANTS Database / Growable Ground plant catalog. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.
When to Plant Knockout Rose in Louisiana
The frost window
Across Louisiana, the last spring hard freeze (28°F) clears between Jan 30 and Feb 17, and the first fall hard freeze lands between Nov 30 and Dec 8 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 286-day window you can count on — up to 312 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
Louisiana runs as cold as USDA zone 8, and no sourced winter-hardiness floor is on record for knockout rose, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether knockout rose is a permanent planting or a replant-every-spring crop for you turns on your own zone within Louisiana; check its hardiness range against that before treating it as long-lived ground.
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 knockout rose survives winter here. Whether the season is long enough — and warm enough — is a different question.
Chill hours
Knockout Rose requires ~200 chill hours (32-45°F dormancy window). Louisiana typically banks ~641 chill hours per winter (from PRISM 1991-2020 climate normals), which keeps this plant on track.
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
Drainage matters: this plant wants well (dry spells). If your Louisiana 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. Louisiana soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
Knockout Rose in Louisiana — Quick Answer
- Verdict: Yes — Strong Match
- Plant Zones: 5-11 (USDA PLANTS Database)
- State Zones: 8b-10b (USDA ARS PHZM 2023)
- Growing Season: 28°F hard freezes about Jan 30 - Feb 17 to Nov 30 - Dec 8 (NOAA Regional Climate Centers ACIS, 1991-2020)
What Else to Consider for Knockout Rose in Louisiana
Zone compatibility tells you about winter cold survival — but Louisiana growers also need to think about:
Extreme humidity and rainfall promote rot and fungal diseases
Poor drainage in delta and coastal areas
Hurricane damage risk from June through November
What to actually do about these — and the constraints that apply to every Louisiana grower, not just knockout rose — is covered on the Louisiana growing guide.
Where in Louisiana Knockout Rose Is Zone-Hardy
Knockout Rose is rated for USDA zones 5–11. Every one of Louisiana’s 64 counties sits inside that band — from Bienville County at zone 8b to Plaquemines County at zone 10a — so winter cold is not what decides this plant anywhere in the state. What is left to vary is your own parcel: slope, shelter and cold-air drainage routinely move a site half a zone either way from the county figure.
Across those 64 counties Louisiana’s winter-low ladder runs from zone 8b in Bienville County to zone 10a in Plaquemines County — 1.5 USDA zones of spread, which is 15°F between the two counties’ average coldest night of the year. That is why a statewide hardiness answer is where you start and not where you finish.
The planting window moves with it. Claiborne County holds its last hard freeze (28°F) until about Mar 2, while St. Bernard County is clear by Jan 16 — 45 days apart. Set knockout rose out on your county’s date, not the state’s.
County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. County last-freeze dates: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F killing freeze — earlier than the folk 32°F "last frost". Knockout Rose’s zone 5–11 band: USDA PLANTS / Growable Ground plant database. A parcel report resolves your address’s own zone and frost dates rather than its county’s.
Where in Louisiana Fits Best
Even within Louisiana's zones 8b-10b, county microclimates differ enough to change what thrives. These counties carry the closest zone match for knockout rose (USDA PHZM 2023):
Pollinator + Wildlife Value
Knockout Rose draws honeybees and native bees (moderate value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, knockout rose can only work that bloom inside Louisiana's frost window — roughly 298 days, opening after the last 28°F freeze (Jan 30 - Feb 17) and closing at the first (Nov 30 - Dec 8), per NOAA Regional Climate Centers ACIS, 1991-2020.
Louisiana Cooperative Extension
For Louisiana-specific cultivar recommendations, planting calendars, and pest pressure for knockout rose, the canonical source is LSU AgCenter. Their fact sheets carry the local trial data we can't generalize across 50 states.
Common Questions About Growing Knockout Rose in Louisiana
When can I plant Knockout Rose in Louisiana?
Louisiana's last spring hard freeze (28°F) clears between Jan 30 and Feb 17, and the first fall hard freeze lands between Nov 30 and Dec 8 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for Knockout Rose, so this page does not state whether it overwinters in Louisiana 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 Knockout Rose grown in across Louisiana?
Louisiana spans USDA hardiness zones 8b-10b (USDA ARS PHZM 2023). Knockout Rose carries a range of zones 5-11, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical Louisiana site have?
A typical Louisiana site sees ~298 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Knockout Rose 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 Knockout Rose actually grow on my specific land in Louisiana?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores knockout rose 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 Louisiana
State-level data is a sketch. Your Growable Ground report scores knockout rose against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Louisiana knockout rose averages can't show:
We read public map data around Louisiana — soil, climate, flood, and parcel records. How we handle your address.
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