Unlikely — Zone Mismatch
para grass (zones 10-13) does not overlap with District of Columbia's zone range (7b-8a). Growing outdoors is unlikely without significant protection.
2 zones short — what would close it
Para Grass is hardy to zone 10, and the warmest ground in District Of Columbia is zone 8 — 2 zones short. Planted in open ground it will not survive a District Of Columbia winter. To grow it here, grow para grass under glass — a greenhouse is the only lift this wide the engine models.
A greenhouse is the lift this needs. How a greenhouse changes what you can grow →
Zone math from 10-13 (plant) against 7-8 (District of Columbia). Lift modeled by crop_engine Sprint 20B effective_zone_modifier (+2 zones) via api/fast_sections.py Unlock Engine v2.
Your yard isn't the whole zone.
District of Columbia spans zones 7b-8a, but your yard has its own microclimate — slope, trees, and low spots shift frost and sun across a single parcel. Enter your address and we'll score para grass against your land's actual soil, sun, and frost.
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Zone Comparison
Para Grass Needs
- USDA Zones: 10-13
- Frost-Free Days: 120+
- Sun: Full Sun
- Mature size: 5 ft tall
- Drought tolerance: Low
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 10-13)
Preferred Soil pH
Plant data: USDA PLANTS Database / Growable Ground plant catalog. State data: USDA ARS PHZM 2023, NOAA Climate Normals, NRCS SSURGO.
When to Plant Para Grass 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.
Frost tenderness
Para Grass is frost-tender — its listed minimum temperature is 59°F (USDA PLANTS Database) — 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.
Days to maturity vs. the window
At 90 days to maturity (USDA PLANTS Database), counting from the last hard freeze it ripens with 164 days to spare even in District of Columbia's tightest freeze scenario — room for a later start or a second sowing.
Frost window: NOAA Climate Normals 1991-2020. Plant timing fields: USDA PLANTS Database. 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 para grass does not survive a District of Columbia winter in the ground. The season figures below measure a different question — whether it could finish a season here at all — and they only bear on District of Columbia under protection.
Frost-free days
Para Grass 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
Para Grass needs ~3000 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
Para Grass tolerates a wide pH range (pH 4.3-7.7) — 3.4 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 — worth knowing before you decide whether a District of Columbia soil test result is a problem or just a number. Drainage requirement: poorly (saturated >50% of year). A soil-survey lookup (NRCS SSURGO) flags whether your specific site matches.
Your land, not the state average
District Of Columbia's soils run mostly silt loam, but SSURGO maps the series, texture, and drainage under your exact parcel. Para Grass needs about 19 inches of workable depth, so it is that horizon — not the surface — you are testing for. That map unit, not the state average, decides how para grass performs.
Check your parcel → Source: USDA NRCS SSURGO.
Plant pH and drainage requirements from USDA PLANTS Database. District of Columbia soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
Para Grass in District of Columbia — Quick Answer
- Verdict: Unlikely — Zone Mismatch
- Plant Zones: 10-13 (USDA PLANTS Database)
- State Zones: 7b-8a (USDA ARS PHZM 2023)
- Growing Season: 28°F hard freezes about Mar 15 to Nov 24 (NOAA Regional Climate Centers ACIS, 1991-2020)
- Days to Maturity: 90 days
What Else to Consider for Para Grass 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
Growing para grass here specifically
Para Grass wants pH 4.3–7.7 and rates to USDA zones 10–13, but District Of Columbia's soils are dominantly silt loam — the fit is decided by your parcel's own map unit, not the state average.
Match para grass to your parcel's SSURGO map unit — test pH and texture, and amend toward its 4.3–7.7 range. How to handle it →
What to actually do about these — and the constraints that apply to every District of Columbia grower, not just para grass — is covered on the District of Columbia growing guide.
District of Columbia Cooperative Extension
For District of Columbia-specific cultivar recommendations, planting calendars, and pest pressure for para grass, 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 Para Grass in District of Columbia
When can I plant Para Grass 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). Para Grass is frost-tender — its listed minimum temperature is 59°F (USDA PLANTS Database) — so wait two to three weeks past your site's last hard freeze, when light frost has also stopped, before planting out.
Can Para Grass mature before first frost in District of Columbia?
Yes — Para Grass matures in 90 days (USDA PLANTS Database), and District of Columbia's dependable hard-freeze-free window runs 254 days (NOAA Regional Climate Centers ACIS, 1991-2020), leaving 164 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 Para Grass grown in across District of Columbia?
District of Columbia spans USDA hardiness zones 7b-8a (USDA ARS PHZM 2023). Para Grass carries a range of zones 10-13, 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). Para Grass 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 Para Grass in District of Columbia?
Para Grass tolerates pH 4.3-7.7 and poorly (saturated >50% of year) drainage (FAO ECOCROP). That is a 3.4-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 Para Grass actually grow on my specific land in District of Columbia?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores para grass 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 para grass against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that District of Columbia para grass 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 para grass average
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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