Zones Fit — Chill Unconfirmed
Hardiness allows river birch here — the zones overlap. Winter chill is the harder question, and our chill-hour figure for this plant is not corroborated against a published source, so we do not publish a verdict on it. The chill line below shows what Louisiana typically banks; treat it as a starting point and confirm with a local Extension office.
River Birch in Louisiana — the short answer
River Birch in Louisiana: hardy in zones 4–10, full sun, against a state median of ~298 frost-free days.
- Plant zones
- 4-10
- 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
- Louisiana zones
- 8b-10b
- USDA PHZM 2023
- Frost window
- Jan 30 - Feb 17 – Nov 30 - Dec 8
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 265 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.
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 river birch against your parcel's actual hardiness, soil, and sun.
We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.
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Louisiana is not one climate
Louisiana’s winter-low ladder runs across 64 counties, from zone 8.5 in Bienville County to zone 10 in Plaquemines County. That is 15°F between the two counties’ average coldest night — the difference between river birch overwintering in the ground and coming under cover.
The middle half of 64 counties runs 8.5–9 zones, with a median of 9 zones — a 1.5-zone span end to end.
Measured across 64 Louisiana 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.
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 river birch (USDA PHZM 2023):
Zone Comparison
River Birch Needs
- USDA Zones: 4-10
- Sun: Full Sun
- Mature size: 60 ft tall
- Drought tolerance: Low
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 4-10)
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 River Birch 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 river birch, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether river birch 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.
Timing tuned to sub-state frost dates — Claiborne 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 river birch survives winter here. Whether the season is long enough — and warm enough — is a different question.
Chill hours
River Birch requires ~800 chill hours (32-45°F dormancy window). Louisiana typically banks ~641 chill hours per winter, short of this plant's requirement — fruit set may suffer in mild years without a low-chill cultivar.
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
River Birch tolerates a wide pH range (pH 3-6.5) — 3.5 units, acid ground through alkaline — so soil acidity is rarely what limits it in Louisiana. A soil test is still worth having, but for what else it tells you about this site, not to clear this plant. Drainage matters: this plant wants poorly (saturated >50% of year), well (dry spells). If your Louisiana site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
Your land, not the state average
Louisiana's soils run mostly silt loam, but SSURGO maps the series, texture, and drainage under your exact parcel. What matters for river birch is the horizon its roots actually work, not the surface. That map unit, not the state average, decides how river birch 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. Louisiana soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
What Else to Consider for River Birch 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
Growing river birch here specifically
Louisiana's soils run mostly silt loam (Alfisols), and whether that suits river birch's pH 3.0–6.5 preference comes down to your exact parcel, not the statewide picture.
Pull your parcel's SSURGO map unit, test pH, and amend toward river birch's 3.0–6.5 target before planting. How to handle it →
What to actually do about these — and the constraints that apply to every Louisiana grower, not just river birch — is covered on the Louisiana growing guide.
Timing shifts within Louisiana
Louisiana isn't one climate. In Claiborne County, the last hard freeze (28°F) holds until about Mar 2 — roughly 19 days later than the recorded state median — so plant river birch to your county's window, not the statewide date.
County last-freeze dates: NOAA Regional Climate Centers ACIS (1991-2020), county 28°F freeze (earlier than the folk 32°F "last frost"). A parcel report resolves your address's own frost dates.
Where in Louisiana River Birch Is Zone-Hardy
River Birch is rated for USDA zones 4–10. 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 river birch 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". River Birch’s zone 4–10 band: USDA PLANTS / Growable Ground plant database. A parcel report resolves your address’s own zone and frost dates rather than its county’s.
Louisiana Cooperative Extension
For Louisiana-specific cultivar recommendations, planting calendars, and pest pressure for river birch, the canonical source is LSU AgCenter. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is River Birch native to Louisiana?
Yes — the USDA PLANTS Database (accessed 2026-07-01) documents River Birch as native to Louisiana. Planting it supports the pollinators and wildlife that evolved alongside it.
Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.
Common Questions About Growing River Birch in Louisiana
When can I plant River Birch 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 River Birch, 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 River Birch grown in across Louisiana?
Louisiana spans USDA hardiness zones 8b-10b (USDA ARS PHZM 2023). River Birch carries a range of zones 4-10, 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). River Birch 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. In cooler counties like Claiborne, the freeze-free season runs shorter than the state average, so verify your own county's window.
Is River Birch native to Louisiana?
Yes — the USDA PLANTS Database (accessed 2026-07-01) documents River Birch as native to Louisiana. Planting it supports the pollinators and wildlife that evolved alongside it.
How should I amend the soil for River Birch in Louisiana?
River Birch tolerates pH 3-6.5 and poorly (saturated >50% of year), well (dry spells) drainage (USDA PLANTS). That is a 3.5-unit span, acid ground through alkaline, so pH is rarely what limits this plant on a Louisiana site — amend for drainage and organic matter first.
Will River Birch actually grow on my specific land in Louisiana?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores river birch 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 river birch against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Louisiana river birch averages can't show:
We read public map data around Louisiana — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Louisiana river birch average
Explore More
Growing guides for river birch
Explore Louisiana county by county
Louisiana carries 64 counties with their own USDA zone — a sample of the growing pages for river birch there:
Where else river birch grows
River Birch's zone band crosses state lines — these are the states closest to Louisiana 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 Louisiana
Louisiana has a growing page for 1,030 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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