annual phlox (Phlox drummondii), photographi

How to Grow Annual Phlox

Phlox drummondii · Zones 2-11

Annual Phlox is an annual grown for its blooms, which open from spring through summer. Season length, not a winter zone, decides where it grows. Notably, it shrugs off deer and grows just as well in a container as in the ground. Its flowers are a real draw for native bees, butterflies, hummingbirds, and moths.

Annual Phlox — the short answer

Annual Phlox: grown in zones 2–11, full sun, pH 5.5–7.5, about 60 days to maturity.

USDA zones
Grown as an annual — see the growing season
Growing season, not a hardiness zone
Soil pH
5.5–7.5
We haven't confirmed this against a published source yet.
Sun
Full Sun
We haven't confirmed this against a published source yet.
Days to Maturity
60 days
We haven't confirmed this against a published source yet.
Frost-kill temp (growing season)
32°F
We haven't confirmed this against a published source yet.

Plant data: Growable Ground Plant Database, compiled from FAO ECOCROP, USDA PLANTS and university Extension sources — each tile names its own row's source, because per-field provenance varies.

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Score Annual Phlox on your exact land.

Zone averages can't see the slope, soil, frost, and sun that decide whether annual phlox actually takes — and those shift from one yard to the next. Enter your address and we'll score annual phlox against your land's real conditions.

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What Annual Phlox is

Annual Phlox grows as an annual and reaches around a foot at maturity. It blooms from spring through summer. It's also deer-resistant and well suited to containers.

Mature height, deer resistance and container suitability: We haven't confirmed this against a published source yet.

How to grow Annual Phlox

Season length, not a winter zone, decides where annual phlox grows. Annual Phlox does best in full sun — at least 6 hours of direct sun a day — and soil from pH 5.5 to 7.5, on well-drained ground. It needs around 1,000 growing degree days to mature and a growing season of at least 60 frost-free days, which is why climate matters as much as soil.

USDA Zones

Grown as an annual — see the growing season

Soil pH

5.5 - 7.5

We haven't confirmed this against a published source yet.

Sun

Full Sun

We haven't confirmed this against a published source yet.

Drainage

well (dry spells)

We haven't confirmed this against a published source yet.

Frost Kill Temperature

32°F

Where cold starts killing growing tissue. Not a winter-survival floor — a dormant perennial takes far colder, which its hardiness zone answers.

We haven't confirmed this against a published source yet.

Days to Maturity

60 days

We haven't confirmed this against a published source yet.

GDD Required

1000+

Growing degree-days of accumulated warmth it needs to mature — humid summers reach this faster than cool coastal ones.

We haven't confirmed this against a published source yet.

Mature Height

1 ft

We haven't confirmed this against a published source yet.

Frost-Free Days

60+

The frost-free stretch it needs start to finish — short-season areas may need an indoor head start.

Growable Ground plant catalog

  1. Start the season right

    Plant annual phlox in full sun with at least 6 hours of direct sun. It grows in the cool halves of the year, so sow it in spring or late summer rather than waiting for midsummer heat. We haven't confirmed this against a published source yet.

  2. Match the soil

    Annual Phlox prefers pH 5.5 to 7.5. We haven't confirmed this against a published source yet. A quick soil test from your local Extension lab tells you whether to add lime or sulfur to land in band.

  3. Water steadily

    Keep the root zone evenly moist through establishment. We haven't confirmed this against a published source yet. A 2–3 inch mulch layer holds moisture without waterlogging.

  4. Harvest at its peak

    Cut annual phlox blooms in the cool of the morning, just as they open, for the longest display.

Where Annual Phlox thrives

Season length, not a winter zone, decides where annual phlox grows. Zone is only the starting point, though: the soil pH, drainage, and frost dates on your specific land decide how well it actually does.

A USDA zone is a 10°F band of average annual extreme winter minimum, so zones 2–11 spans average winter lows from -50°F to 50°F (USDA PHZM 2023). Across the 50 states and DC, that band covers 48 outright and splits 3 more down the middle.

Zones 2–11 highlighted on the USDA national hardiness zone map

Zones 2–11·Hardiness bandOpen map →

Continental US shown — Alaska and US Pacific territories sit outside the federal map's polygon dataset.

This map is derived from the USDA ARS / PRISM Plant Hardiness Zone Map (2023) and is not the official USDA Plant Hardiness Zone Map.

Where Annual Phlox stands, state by state

Annual Phlox is rated for zones 2–11 — a cold floor USDA puts at -50 to -40°F. Across the 50 states and DC, 48 sit fully inside that band, the line runs through 3 more, and 0 sit outside it — and inside every split state, the same line runs on at county grain.

Fully inside zones 2–11

48 states

3 of 48 shown

The line runs through

3 states

State zone extents: USDA Plant Hardiness Zone Map (PHZM) 2023. A zone is a 10°F band of average annual extreme minimum temperature, so a state that splits the band contains the boundary — its own page draws the county line, and a parcel report resolves which side your land sits on.

Good to know

Annual Phlox is a standout pollinator plant — high value to bees and other pollinators. We haven't confirmed this against a published source yet.

Your land is one point inside Annual Phlox's range

This page resolves to the species. Your state page draws the county line, and a report reads the parcel — the soil pH, drainage, sun, and frost dates on your exact ground, which no species average can see.

Free to start

See if Annual Phlox will thrive on your land

Zone averages are a start. Your soil pH, drainage, sun exposure, and frost dates shape whether annual phlox actually takes. We score it against the mapped and modelled conditions at your address.

Three things about your exact spot that zone averages miss:

Your soil pHYour frost-free daysYour sun & shade

We read public map data for this spot — soil, climate, flood, and parcel records. How we handle your address.

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How we know this about Annual Phlox

The figures above are cited per row, not per site: the pH band names this plant’s own source column, the three temperature figures each carry their own, and days-to-maturity cites the publication that actually lists it. All of it comes from the Growable Ground Plant Database — a compilation over FAO ECOCROP, USDA PLANTS, and university Extension sources, published openly with per-field provenance.

Grounded inUSDA PLANTS Database

Frequently asked questions

Can I grow Annual Phlox in my zone?

Annual Phlox is grown as an annual, so a hardiness zone does not decide it — its growing season follows your last and first frost dates. Soil pH, drainage, and frost dates on your specific parcel also shape whether it takes.

When should you plant Annual Phlox?

Annual Phlox is a cool-season crop, so it goes in during the cool halves of the year — early spring, and again in late summer for a fall planting — rather than at the height of summer heat. Your local frost dates set the exact window — a Growable Ground report reads them for your address.

How much sun does Annual Phlox need?

Annual Phlox needs full sun — a spot that catches at least 6 hours of direct summer sun a day. We haven't confirmed this against a published source yet. In more shade it still grows, but usually gives a smaller, later crop. The catch is that a yard rarely gets even light everywhere — a fence, the house, or one tall tree can quietly take those hours. A Growable Ground report reads the real sun-hours across your land, canopy and buildings included, so you can pick the brightest bed before you plant.

What soil does Annual Phlox need?

Annual Phlox prefers soil pH 5.5 to 7.5, on well-drained ground. We haven't confirmed this against a published source yet. Your report scores your parcel's mapped soil against that using USDA SSURGO data.

Does Annual Phlox attract pollinators?

Yes — annual phlox's flowers are a strong nectar and pollen source for native bees, butterflies, hummingbirds, and moths. We haven't confirmed this against a published source yet.