annual phlox (Phlox drummondii), photographi

Can I Grow Annual Phlox in Georgia?

USDA Zones 7a-9b · Plant zone range 2-11

Yes — Strong Match

annual phlox (zones 2-11) covers every zone Georgia contains (7a-9b), so hardiness is not what limits it anywhere in the state.

Annual Phlox in Georgia — the short answer

Annual Phlox in Georgia: hardy in zones 2–11, full sun, against a state median of ~275 frost-free days.

Plant zones
2-11
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
Georgia zones
7a-9b
USDA PHZM 2023
Frost window
Feb 17 - Mar 10 – Nov 24 - Dec 4
NOAA RCC ACIS 1991-2020, 28°F
Shortest county season
204 days
NOAA Regional Climate Centers ACIS, 1991-2020, county 28°F killing freeze
Days to maturity
60 days
Growable Ground Plant Database

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.

Score your parcel · free

Your yard isn't the whole zone.

Annual Phlox is grown as an annual, so your winter zone isn't the deciding factor — your frost-free window is. A typical Georgia site runs ~275 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 annual phlox 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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Georgia is not one climate

A single Georgia answer averages 159 counties whose growing seasons are 101 days apart — from 204 frost-free days in Towns County to 305 in Colquitt County. Which end of that your land sits nearer changes what annual phlox can finish before the first hard freeze.

204 daysTowns County305 daysColquitt County

The middle half of 159 counties runs 259290 days, with a median of 275 days — a 101-day span end to end.

Measured across 159 Georgia 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 Georgia Fits Best

Even within Georgia's zones 7a-9b, county microclimates differ enough to change what thrives. These counties carry the closest zone match for annual phlox (USDA PHZM 2023):

Zone Comparison

Annual Phlox Needs

  • USDA Zones: 2-11
  • Frost-Free Days: 60+
  • Sun: Full Sun
  • Mature size: 1 ft tall
  • Picking window: ~60 days of harvest
  • Drought tolerance: Medium

Georgia Has

  • USDA Zones: 7a-9b
  • Last Hard Freeze (28°F): Feb 17 - Mar 10
  • First Hard Freeze (28°F): Nov 24 - Dec 4
  • Annual Rainfall: 45-55 inches
  • Common Soils: Red clay (Piedmont), Sandy loam (Coastal Plain), Alluvial

Plant Zone Range (zones 2-11)

2a
11b
3a (Cold)13b (Hot)

Preferred Soil pH

3.5 (Acidic)7.0 (Neutral)9.0 (Alkaline)
Highlighted range: pH 5.57.5

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 Annual Phlox in Georgia

The frost window

Across Georgia, the last spring hard freeze (28°F) clears between Feb 17 and Mar 10, and the first fall hard freeze lands between Nov 24 and Dec 4 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 259-day window you can count on — up to 290 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.

Frost tenderness

Annual Phlox is frost-tender — FAO ECOCROP puts its killing temperature at 32°F — so set plants out two to three weeks PAST your local last hard freeze, not on it and not on the state's earliest date. The 28°F marker above is when killing freezes stop, not when light frost does. That is the point where cold damages growing tissue, not a winter-survival floor — an established perennial comes through far colder while dormant, which is what its hardiness zone tells you.

When to start the seed

Annual Phlox is direct-sown where it grows rather than started under cover, so there is no seed-tray head start to bank — Georgia's dates above are the whole calendar for it. That makes the last-freeze date the binding constraint, and a warmer pocket of your own yard is worth more to this crop than it is to a transplanted one.

Days to maturity vs. the window

At 60 days to maturity (Growable Ground Plant Database), counting from the last hard freeze it ripens with 199 days to spare even in Georgia's tightest freeze scenario — room for a later start or a second sowing.

Timing tuned to sub-state frost dates — Towns 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 annual phlox survives winter here. Whether the season is long enough — and warm enough — is a different question.

Frost-free days

Annual Phlox wants 60+ frost-free days; a typical Georgia site sees ~275 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.

Growing degree days

Annual Phlox needs ~1000 GDD (base 50°F) to ripen. The state median runs ~5616 GDD (from PRISM 1991-2020 climate normals), so Georgia's typical season clears that easily.

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

Annual Phlox likes near-neutral soil (pH 5.5-7.5). That's the common-ground band across Georgia's red clay (piedmont) and sandy loam (coastal plain) — 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 Georgia soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Georgia site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.

Your land, not the state average

SSURGO maps about 20.4% of Georgia as poorly or somewhat-poorly drained, and the class flips parcel to parcel. Annual Phlox sits mid-range for drought tolerance, so either extreme can cost you — your soil map unit, not the state average, is the real answer.

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. Georgia soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.

What Else to Consider for Annual Phlox in Georgia

Zone compatibility tells you about winter cold survival — but Georgia growers also need to think about:

Heavy red Piedmont clay is difficult to work and drains poorly

High humidity drives fungal diseases in summer

Fire ants are a persistent pest in gardens across the state

Summer heat (90-100F) can stress cool-season crops by May

Growing annual phlox here specifically

Annual Phlox rates to USDA zones 2–11 and takes frost damage on growing tissue around 32°F (FAO ECOCROP), but cold isn't the risk in Georgia — wet is: with roughly 20.4% of its soils poorly-drained (SSURGO), soggy ground rots the roots.

Give annual phlox a raised bed or mounded row with coarse amendment so its roots never sit wet. How to handle it →

What to actually do about these — and the constraints that apply to every Georgia grower, not just annual phlox — is covered on the Georgia growing guide.

Timing shifts within Georgia

Georgia isn't one climate. In Towns County, the last hard freeze (28°F) holds until about Apr 7 — roughly 39 days later than the recorded state median — so plant annual phlox to your county's window, not the statewide date.

Annual Phlox needs about 60 days of frost-free season to complete its cycle. Even Towns County — Georgia’s shortest season at 204 frost-free days — clears that by 144 days, so season length isn’t the constraint anywhere in Georgia. What varies is your own parcel.

Across Georgia’s 159 counties the frost-free season runs from 204 days in Towns County to 305 days in Colquitt County — a spread of 101 days, which is why a single statewide planting date misleads. The median Georgia county sees 275 frost-free days, leaving annual phlox about 215 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"). Annual Phlox's 60-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

Annual Phlox draws native bees, butterflies, hummingbirds, and moths (high value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, annual phlox can only work that bloom inside Georgia's frost window — roughly 275 days, opening after the last 28°F freeze (Feb 17 - Mar 10) and closing at the first (Nov 24 - Dec 4), per NOAA Regional Climate Centers ACIS, 1991-2020.

Recommended Annual Phlox Varieties for Georgia

Georgia publishes no state variety trial for annual phlox, so we won't invent a "best for Georgia" list. Choose types rated to your USDA hardiness zone (7a-9b), and confirm winter survival and drainage against your own parcel.

Georgia Cooperative Extension

For Georgia-specific cultivar recommendations, planting calendars, and pest pressure for annual phlox, the canonical source is UGA Cooperative Extension. Their fact sheets carry the local trial data we can't generalize across 50 states.

Is Annual Phlox native to Georgia?

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

Looking for plants that belong here? The Georgia growing guide lists USDA-documented natives for the state.

Native-range data: USDA PLANTS Database state-distribution records, accessed 2026-07-01.

Common Questions About Growing Annual Phlox in Georgia

When can I plant Annual Phlox in Georgia?

Georgia's last spring hard freeze (28°F) clears between Feb 17 and Mar 10, and the first fall hard freeze lands between Nov 24 and Dec 4 (NOAA Regional Climate Centers ACIS, 1991-2020). Annual Phlox is frost-tender — its killing temperature is 32°F (FAO ECOCROP — the point where cold damages growing tissue, not a winter-survival floor) — so wait two to three weeks past your site's last hard freeze, when light frost has also stopped, before planting out.

Can Annual Phlox mature before first frost in Georgia?

Yes — Annual Phlox matures in 60 days (Growable Ground Plant Database), and Georgia's dependable hard-freeze-free window runs 259 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 199 days of margin. Plant once the last hard freeze has passed — two to three weeks later for anything tender — and it ripens ahead of the first fall freeze.

What hardiness zone is Annual Phlox grown in across Georgia?

Georgia spans USDA hardiness zones 7a-9b (USDA ARS PHZM 2023). Annual Phlox carries a range of zones 2-11, so the overlap zones are where outdoor growing is most reliable.

How many frost-free days does a typical Georgia site have?

A typical Georgia site sees ~275 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Annual Phlox needs 60+ 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 Towns, the freeze-free season runs shorter than the state average, so verify your own county's window.

Is Annual Phlox native to Georgia?

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

How should I amend the soil for Annual Phlox in Georgia?

Annual Phlox prefers pH 5.5-7.5 and well (dry spells) drainage (Growable Ground Plant Database). That sits in the common-ground band across Georgia soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.

Will Annual Phlox actually grow on my specific land in Georgia?

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

Free Report

Check your specific parcel in Georgia

State-level data is a sketch. Your Growable Ground report scores annual phlox against your parcel's exact soil, sun, drainage, and frost data — not zone averages.

Three things about your lot that Georgia annual phlox averages can't show:

Your soil pHYour frost-free days — Georgia averages 275Your sun & shade

We read public map data around Georgia — soil, climate, flood, and parcel records. How we handle your address.

25+ data sources read at your address, not the Georgia annual phlox average

Explore More

Explore Georgia county by county

Georgia carries 159 counties with their own USDA zone — a sample of the growing pages for annual phlox there:

Where else annual phlox grows

Annual Phlox's zone band crosses state lines — these are the states closest to Georgia 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 Georgia

Georgia has a growing page for 1,034 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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