Conditional — Some Areas
St. Augustine grass (zones 8-10) reaches only part of Alaska (1a-9a): zones 8-9 are in range, so where you are in the state decides it.
St Augustine Grass in Alaska — the short answer
St Augustine Grass in Alaska: hardy in zones 8–10, part sun.
- Plant zones
- 8-10
- Not verified — NC State Extension Gardener Plant Toolbox lists zones 7a–12b
- Alaska zones
- 1a-9a
- USDA PHZM 2023
- Frost window
- Apr 16 - May 15 – Sep 24 - Oct 29
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 85 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.
Your yard isn't the whole zone.
Alaska spans zones 1a-9a, 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 st augustine grass 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.
No card required · your parcel report in seconds — read in full free for your first 14 days
Alaska is not one climate
Alaska’s winter-low ladder runs across 30 counties, from zone 1 in Yukon-Koyukuk County to zone 7.5 in Chugach County. That is 65°F between the two counties’ average coldest night — the difference between st augustine grass overwintering in the ground and coming under cover.
The middle half of 30 counties runs 2.5–5 zones, with a median of 4 zones — a 6.5-zone span end to end.
Measured across 30 Alaska 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 St Augustine Grass Stands in Alaska
St Augustine Grass is rated for zones 8–10 — a cold floor USDA puts at 10 to 20°F. No Alaska county sits inside it, so in open ground this is a grown-under-cover plant here rather than a bed plant — which is a statement about Alaska winters, not about st augustine grass.
Below the zone 8 floor
30 counties
- Yukon-Koyukuk County · zone 1a-4a
- North Slope County · zone 1b-4a
- Northwest Arctic County · zone 1b-4a
3 of 30 shown
Winter cold is the limit here — the same plant works in a container that comes under cover.
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.
Zone Comparison
St Augustine Grass Needs
- USDA Zones: 8-10
- Sun: Part Sun
- Mature size: 1 ft tall
- Drought tolerance: Medium
Alaska Has
- USDA Zones: 1a-9a
- Last Hard Freeze (28°F): Apr 16 - May 15
- First Hard Freeze (28°F): Sep 24 - Oct 29
- Annual Rainfall: 10-160 inches
- Common Soils: Permafrost, Glacial silt, Volcanic ash
Plant Zone Range (zones 8-10)
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 St Augustine Grass in Alaska
The frost window
Across Alaska, the last spring hard freeze (28°F) clears between Apr 16 and May 15, and the first fall hard freeze lands between Sep 24 and Oct 29 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 132-day window you can count on — up to 196 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
Alaska runs as cold as USDA zone 1, and no sourced winter-hardiness floor is on record for st augustine grass, so this page does not state whether it overwinters here — and gives no fall establishment date on the strength of a guess. Whether st augustine grass is a permanent planting or a replant-every-spring crop for you turns on your own zone within Alaska; check its hardiness range against that before treating it as long-lived ground.
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.
Soil + Drainage Fit
St Augustine Grass tolerates a wide pH range (pH 5-8.5) — 3.5 units, acid ground through alkaline — so soil acidity is rarely what limits it in Alaska. 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 6 and 7.5 — worth knowing before you decide whether a Alaska soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Alaska 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. Alaska soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
What Else to Consider for St Augustine Grass in Alaska
Zone compatibility tells you about winter cold survival — but Alaska growers also need to think about:
Extremely short growing season (70-110 frost-free days)
Permafrost prevents deep root growth in many areas
Limited soil development in glacial terrain
What to actually do about these — and the constraints that apply to every Alaska grower, not just st augustine grass — is covered on the Alaska growing guide.
Where in Alaska St Augustine Grass Is Zone-Hardy
St Augustine Grass is rated for USDA zones 8–10. No single Alaska county falls inside it: 22 are colder than the plant’s zone 8 floor and 0 are milder than its zone 10 ceiling. A band this narrow straddles the state rather than sitting inside it.
Across those 30 counties Alaska’s winter-low ladder runs from zone 1a-4a in Yukon-Koyukuk County to zone 7b in Chugach County — 6.5 USDA zones of spread, which is 65°F between the two counties’ average coldest night of the year. None of that range reaches the band st augustine grass needs, so here the statewide answer really is the answer.
County hardiness zones: USDA Plant Hardiness Zone Map (PHZM) 2023, per county. St Augustine Grass’s zone 8–10 band: Not verified — NC State Extension Gardener Plant Toolbox lists zones 7a–12b. A parcel report resolves your address’s own zone and frost dates rather than its county’s.
Alaska Cooperative Extension
For Alaska-specific cultivar recommendations, planting calendars, and pest pressure for st augustine grass, the canonical source is UAF Cooperative Extension Service. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is St Augustine Grass native to Alaska?
St Augustine Grass is native to parts of the Lower 48, but the USDA PLANTS Database (accessed 2026-10-19) does not record it growing in Alaska. It can still earn a place in a Alaska garden — the zone comparison above tells you whether it will thrive.
Looking for plants that belong here? The Alaska growing guide lists plants that USDA PLANTS records growing in Alaska 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 St Augustine Grass in Alaska
When can I plant St Augustine Grass in Alaska?
Alaska's last spring hard freeze (28°F) clears between Apr 16 and May 15, and the first fall hard freeze lands between Sep 24 and Oct 29 (NOAA Regional Climate Centers ACIS, 1991-2020). No sourced winter-hardiness floor is on record for St Augustine Grass, so this page does not state whether it overwinters in Alaska 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 St Augustine Grass grown in across Alaska?
Alaska spans USDA hardiness zones 1a-9a (USDA ARS PHZM 2023). St Augustine Grass carries a range of zones 8-10, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical Alaska site have?
A typical Alaska site sees ~147 frost-free days per year (derived from NOAA Regional Climate Centers ACIS station record, 1991-2020). St Augustine Grass needs 150+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.
Is St Augustine Grass native to Alaska?
St Augustine Grass is native to parts of the Lower 48, but the USDA PLANTS Database (accessed 2026-10-19) does not record it growing in Alaska. It can still earn a place in a Alaska garden — the zone comparison above tells you whether it will thrive.
How should I amend the soil for St Augustine Grass in Alaska?
St Augustine Grass tolerates pH 5-8.5 and well (dry spells) drainage (FAO ECOCROP). That is a 3.5-unit span, acid ground through alkaline, so pH is rarely what limits this plant on a Alaska site — amend for drainage and organic matter first.
Will St Augustine Grass actually grow on my specific land in Alaska?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores st augustine grass against your address's mapped soil pH, drainage, sun, and frost-date data drawn from USDA SSURGO, NOAA, and PRISM — not state averages.
Check your specific parcel in Alaska
State-level data is a sketch. Your Growable Ground report scores st augustine grass against your land's mapped soil, modelled sun, drainage, and frost data — not zone averages.
Three things about your lot that Alaska st augustine grass averages can't show:
We read public map data around Alaska — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Alaska st augustine grass average
Explore More
Growing guides for st augustine grass
Explore Alaska county by county
Alaska carries 30 counties with their own USDA zone — a sample of the growing pages for st augustine grass there:
Where else st augustine grass grows
St Augustine Grass's zone band crosses state lines — these are the states closest to Alaska 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 Alaska
Alaska has a growing page for 1,011 plants — a rotating sample of the rest of the shelf.
Last updated: