Generally — Most Areas
rosemary (zones 8-10) suits most of District of Columbia (7b-8a) — zone 8 are in range, and the rest of the state is the exception.
Rosemary in District of Columbia — the short answer
Rosemary in District of Columbia: hardy in zones 8–10, full sun, against a state median of ~254 frost-free days.
- Plant zones
- 8-10
- 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
- District of Columbia zones
- 7b-8a
- USDA PHZM 2023
- Frost window
- Mar 15 – Nov 24
- NOAA RCC ACIS 1991-2020, 28°F
- Typical season
- ~254 days
- NOAA Regional Climate Centers ACIS, 1991-2020
- Days to maturity
- 90 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.
Your yard isn't the whole zone.
District of Columbia spans zones 7b-8a, 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 rosemary 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 full report in seconds
Where in District of Columbia Fits Best
Even within District of Columbia's zones 7b-8a, county microclimates differ enough to change what thrives. These counties carry the closest zone match for rosemary (USDA PHZM 2023):
Zone Comparison
Rosemary Needs
- USDA Zones: 8-10
- Frost-Free Days: 120+
- Sun: Full Sun
- Mature size: 4 ft tall
- Picking window: ~120 days of harvest
- Drought tolerance: High
District of Columbia Has
- USDA Zones: 7b-8a
- Last Hard Freeze (28°F): Mar 15
- First Hard Freeze (28°F): Nov 24
- Annual Rainfall: 39-43 inches
- Common Soils: Urban fill, Silt loam, Clay loam
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 Rosemary in District of Columbia
The frost window
Across District of Columbia, the last spring hard freeze (28°F) clears between Mar 15 and Mar 15, and the first fall hard freeze lands between Nov 24 and Nov 24 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 254-day window you can count on — up to 254 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.
When to start the seed
Those dates are when rosemary goes out, not when it starts. It is sown under cover about 10 weeks ahead, so counting back from District of Columbia's late-side last freeze of Mar 15 is what fixes your sowing date — and a yard that clears frost earlier than the state's late date starts earlier still.
Winter standing
Rosemary overwinters from USDA zone 8 and warmer (NC State Extension Gardener Plant Toolbox; Missouri Botanical Garden Plant Finder), and District of Columbia runs as cold as zone 7, so it does not survive winter in the ground here. It is a woody plant rather than a crop you resow each spring, so neither a fall establishment date nor a harvest countdown describes it in District of Columbia — which is why this page gives neither. What it needs here is a way through winter, not a planting date.
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 rosemary survives winter in part of District of Columbia, not across all of it. Whether the season is long enough — and warm enough — is a different question.
Frost-free days
Rosemary wants 120+ frost-free days; a typical District of Columbia site sees ~254 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.
Growing degree days
Rosemary needs ~2500 GDD (base 50°F) to ripen. The state median runs ~4070 GDD (from PRISM 1991-2020 climate normals), so District of Columbia'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
Rosemary tolerates a wide pH range (pH 4.2-8.3) — 4.1 units, acid ground through alkaline — so soil acidity is rarely what limits it in District of Columbia. 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 5 and 6.5 — worth knowing before you decide whether a District of Columbia soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your District of Columbia site is heavier clay or sits in a low spot, raised beds or amendment with compost solve it.
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. District of Columbia soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
Before you plant rosemary for food
Anything you grow to eat takes up what is in the ground it grows in, so what is on record near you is worth knowing before rosemary goes in. What follows is District of Columbia’s documented federal record at state scale — a screening signal, not a soil test, and not a statement about any one lot.
Safe to Grow Here?
What the federal record shows across District of Columbia — and how to grow with it.
We checked the federal record across District of Columbia — 2,435 documented sites across 6 of the 9 source types we track.
The most significant on record: 50 Superfund sites. Sites tracked in EPA's Superfund program — from assessment-stage CERCLIS entries to confirmed National Priorities List cleanup sites.
There's a meaningful federal record across District of Columbia — worth a look before you plant food, not a reason to hold back from growing. Proximity to a documented site is information, not a diagnosis of any one yard. A soil test before new food beds is the sensible precaution here, and the map shows exactly which sites sit where, so you can see what's actually near you.
Sources Checked
across District of Columbia
Severity Distribution
across District of Columbia
Highest-Severity Sites
A note from Gnorman
What an experienced grower watches for around here
In and around District of Columbia, Superfund runs higher than the national average — 50 sites across District of Columbia. It's not cause for alarm — it's worth knowing, and there's a sensible way to grow around it.
Superfund: Superfund sites represent the most severe contamination in the federal system.
Commission professional soil testing before any food production (test for heavy metals, VOCs, and SVOCs).
Sources: EPA, USGS — 1.8M documented sites tracked nationwide across 9 federal source types.
What Else to Consider for Rosemary in District of Columbia
Zone compatibility tells you about winter cold survival — but District of Columbia growers also need to think about:
Dense urban siting means small lots, compacted fill soils, and limited sun
Summer heat and humidity promote fungal diseases
The urban heat-island effect pushes summer temperatures above surrounding suburbs
What to actually do about these — and the constraints that apply to every District of Columbia grower, not just rosemary — is covered on the District of Columbia growing guide.
Pollinator + Wildlife Value
Rosemary draws honeybees and native bees (high value, Growable Ground Plant Database). Planting it near vegetable beds can lift fruit set on neighboring crops. Outdoors, rosemary can only work that bloom inside District of Columbia's frost window — roughly 254 days, opening after the last 28°F freeze (Mar 15) and closing at the first (Nov 24), per NOAA Regional Climate Centers ACIS, 1991-2020. Deer pressure is meaningful across much of District of Columbia; rosemary is listed as deer-resistant (USDA PLANTS Database), which makes it a safer pick for unfenced sites. Our deer & wildlife guide carries the full deer-resistant list and how to protect the rest.
District of Columbia Cooperative Extension
For District of Columbia-specific cultivar recommendations, planting calendars, and pest pressure for rosemary, the canonical source is UDC Center for Urban Agriculture. Their fact sheets carry the local trial data we can't generalize across 50 states.
Common Questions About Growing Rosemary in District of Columbia
When can I plant Rosemary in District of Columbia?
District of Columbia's last spring hard freeze (28°F) clears between Mar 15 and Mar 15, and the first fall hard freeze lands between Nov 24 and Nov 24 (NOAA Regional Climate Centers ACIS, 1991-2020). Rosemary overwinters only from USDA zone 8 and warmer, and District of Columbia runs as cold as zone 7, so it does not survive winter in the ground here — the question for District of Columbia growers is how to carry it through winter under cover, not which week to plant it.
What hardiness zone is Rosemary grown in across District of Columbia?
District of Columbia spans USDA hardiness zones 7b-8a (USDA ARS PHZM 2023). Rosemary 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 District of Columbia site have?
A typical District of Columbia site sees ~254 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Rosemary needs 120+ frost-free days, so check whether your local microclimate runs above or below the state average before settling on a planting date.
How should I amend the soil for Rosemary in District of Columbia?
Rosemary tolerates pH 4.2-8.3 and well (dry spells) drainage (FAO ECOCROP). That is a 4.1-unit span, acid ground through alkaline, so pH is rarely what limits this plant on a District of Columbia site — amend for drainage and organic matter first.
Will Rosemary actually grow on my specific land in District of Columbia?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores rosemary 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 District of Columbia
State-level data is a sketch. Your Growable Ground report scores rosemary against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that District of Columbia rosemary averages can't show:
We read public map data around District of Columbia — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the District of Columbia rosemary average
Explore More
Growing guides for rosemary
Last updated: