Unlikely — Zone Mismatch
feather top Rhodes grass (zones 7-11) does not overlap with Iowa's zone range (4b-6a). Growing outdoors is unlikely without significant protection.
One zone short — what would close it
Feather Top Rhodes Grass is hardy to zone 7, and the warmest ground in Iowa is zone 6 — 1 zone short. Planted in open ground it will not survive a Iowa winter. To grow it here, grow feather top rhodes grass in a hoop house or unheated greenhouse — its modeled 1.5-zone lift covers this gap.
A hoop house or unheated greenhouse is the lift this needs. How a greenhouse changes what you can grow →
Zone math from 7-11 (plant) against 4-6 (Iowa). Lift modeled by crop_engine.GREENHOUSE_ZONE_MODIFIER_BY_SUBTYPE['hoop_house'] (+1.5 zones) via api/fast_sections.py Unlock Engine v2.
Feather Top Rhodes Grass in Iowa — the short answer
Feather Top Rhodes Grass in Iowa: hardy in zones 7–11, full sun, against a state median of ~189 frost-free days.
- Plant zones
- 7-11
- 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
- Iowa zones
- 4b-6a
- USDA PHZM 2023
- Frost window
- Apr 10 - Apr 17 – Oct 18 - Oct 23
- NOAA RCC ACIS 1991-2020, 28°F
- Shortest county season
- 168 days
- NOAA Regional Climate Centers ACIS, 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.
Iowa spans zones 4b-6a, 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 feather top rhodes grass against your land's actual soil, sun, and frost.
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
Iowa is not one climate
A single Iowa answer averages 99 counties whose growing seasons are 48 days apart — from 168 frost-free days in Howard County to 216 in Lee County. Which end of that your land sits nearer changes what feather top rhodes grass can finish before the first hard freeze.
The middle half of 99 counties runs 183–197 days, with a median of 189 days — a 48-day span end to end.
Measured across 99 Iowa 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 Feather Top Rhodes Grass Stands in Iowa
Feather Top Rhodes Grass is rated for zones 7–11 — a cold floor USDA puts at 0 to 10°F. No Iowa 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 Iowa winters, not about feather top rhodes grass.
Below the zone 7 floor
99 counties
- Clayton County · zone 4b
- Howard County · zone 4b
- Winneshiek County · zone 4b
3 of 99 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
Feather Top Rhodes Grass Needs
- USDA Zones: 7-11
- Frost-Free Days: 90+
- Sun: Full Sun
Iowa Has
- USDA Zones: 4b-6a
- Last Hard Freeze (28°F): Apr 10 - Apr 17
- First Hard Freeze (28°F): Oct 18 - Oct 23
- Annual Rainfall: 26-36 inches
- Common Soils: Prairie loess, Silt loam, Clay loam
Plant Zone Range (zones 7-11)
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 Feather Top Rhodes Grass in Iowa
The frost window
Across Iowa, the last spring hard freeze (28°F) clears between Apr 10 and Apr 17, and the first fall hard freeze lands between Oct 18 and Oct 23 (NOAA Regional Climate Centers ACIS, 1991-2020). Counting from the latest last freeze to the earliest first freeze, that's a 184-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.
When to start the seed
Feather Top Rhodes Grass is direct-sown where it grows rather than started under cover, so there is no seed-tray head start to bank — Iowa'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.
Timing tuned to sub-state frost dates — Howard 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 feather top rhodes grass does not survive a Iowa 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 Iowa under protection.
Frost-free days
Feather Top Rhodes Grass wants 90+ frost-free days; a typical Iowa site sees ~189 (NOAA Regional Climate Centers ACIS, 1991-2020). That leaves comfortable headroom for succession planting.
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
Feather Top Rhodes Grass likes near-neutral soil (pH 6-8.5). That's the common-ground band across Iowa's prairie loess and silt loam — a soil test confirms it for your site. It will grow across that whole span, but it does best between pH 6.5 and 7.5 — worth knowing before you decide whether a Iowa soil test result is a problem or just a number. Drainage matters: this plant wants well (dry spells). If your Iowa 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 42.9% of Iowa as poorly or somewhat-poorly drained, and the class flips parcel to parcel. Feather Top Rhodes Grass 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. Iowa soil profile from USDA NRCS SSURGO. Site-specific verification: a 30-minute soil test from your local Extension lab.
What Else to Consider for Feather Top Rhodes Grass in Iowa
Zone compatibility tells you about winter cold survival — but Iowa growers also need to think about:
Cold winters reaching -20F or below
Variable spring weather delays planting
Wind exposure on open prairies desiccates plants
Growing feather top rhodes grass here specifically
Feather Top Rhodes Grass roots run medium and prefer pH 6.0–8.5, but drainage comes first here: SSURGO maps about 42.9% of Iowa as poorly or somewhat-poorly drained, and wet ground rots its roots before pH ever matters.
Plant feather top rhodes grass on a raised, gravel-amended berm so water drains fast and the roots stays dry. How to handle it →
What to actually do about these — and the constraints that apply to every Iowa grower, not just feather top rhodes grass — is covered on the Iowa growing guide.
Timing shifts within Iowa
Iowa isn't one climate. In Howard County, the last hard freeze (28°F) holds until about Apr 24 — roughly 10 days later than the recorded state median — so plant feather top rhodes grass to your county's window, not the statewide date.
Feather Top Rhodes Grass needs about 90 days of frost-free season to complete its cycle. Even Howard County — Iowa’s shortest season at 168 frost-free days — clears that by 78 days, so season length isn’t the constraint anywhere in Iowa. What varies is your own parcel.
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"). Feather Top Rhodes Grass's 90-day requirement: USDA PLANTS / Growable Ground plant database (minimum frost-free days). A parcel report resolves your address's own frost dates.
Iowa Cooperative Extension
For Iowa-specific cultivar recommendations, planting calendars, and pest pressure for feather top rhodes grass, the canonical source is Iowa State University Extension and Outreach. Their fact sheets carry the local trial data we can't generalize across 50 states.
Is Feather Top Rhodes Grass native to Iowa?
Feather Top Rhodes Grass is native to parts of the Lower 48, but the USDA PLANTS Database (accessed 2026-07-01) does not document a native range in Iowa. It can still earn a place in a Iowa garden — the zone comparison above tells you whether it will thrive.
Looking for plants that belong here? The Iowa 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 Feather Top Rhodes Grass in Iowa
When can I plant Feather Top Rhodes Grass in Iowa?
Iowa's last spring hard freeze (28°F) clears between Apr 10 and Apr 17, and the first fall hard freeze lands between Oct 18 and Oct 23 (NOAA Regional Climate Centers ACIS, 1991-2020). Time outdoor planting to after the last hard freeze for your specific site — a further two to three weeks for anything tender — and count back from those dates for transplant scheduling.
What hardiness zone is Feather Top Rhodes Grass grown in across Iowa?
Iowa spans USDA hardiness zones 4b-6a (USDA ARS PHZM 2023). Feather Top Rhodes Grass carries a range of zones 7-11, so the overlap zones are where outdoor growing is most reliable.
How many frost-free days does a typical Iowa site have?
A typical Iowa site sees ~189 frost-free days per year (derived from NOAA Regional Climate Centers ACIS, 1991-2020). Feather Top Rhodes Grass needs 90+ 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 Howard, the freeze-free season runs shorter than the state average, so verify your own county's window.
Is Feather Top Rhodes Grass native to Iowa?
Feather Top Rhodes Grass is native to parts of the Lower 48, but the USDA PLANTS Database (accessed 2026-07-01) does not document a native range in Iowa. It can still earn a place in a Iowa garden — the zone comparison above tells you whether it will thrive.
How should I amend the soil for Feather Top Rhodes Grass in Iowa?
Feather Top Rhodes Grass prefers pH 6-8.5 and well (dry spells) drainage (FAO ECOCROP). That sits in the common-ground band across Iowa soils — a 30-minute soil test from a local Extension lab confirms it for your specific site.
Will Feather Top Rhodes Grass actually grow on my specific land in Iowa?
State-level zone + climate data is a sketch. A Growable Ground parcel report scores feather top rhodes 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 Iowa
State-level data is a sketch. Your Growable Ground report scores feather top rhodes grass against your parcel's exact soil, sun, drainage, and frost data — not zone averages.
Three things about your lot that Iowa feather top rhodes grass averages can't show:
We read public map data around Iowa — soil, climate, flood, and parcel records. How we handle your address.
25+ data sources read at your address, not the Iowa feather top rhodes grass average
Explore More
Growing guides for feather top rhodes grass
Explore Iowa county by county
Iowa carries 99 counties with their own USDA zone — a sample of the growing pages for feather top rhodes grass there:
Where else feather top rhodes grass grows
Feather Top Rhodes Grass's zone band crosses state lines — these are the states closest to Iowa 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 Iowa
Iowa has a growing page for 806 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
Last updated: