Native plants · Iowa

Native plants of Delaware County

21 plant species are recorded as native to Iowa in Kew’s World Checklist of Vascular Plants and USDA PLANTS, and recorded in Delaware County by USDA PLANTS. 8 of them have growing records you can filter by light, moisture, height and estimated cold hardiness.

County summary · USDA PLANTS and Kew WCVP

Delaware County, Iowa

PLANTS records only 8 garden-ready natives here (under 30). County records are thin in some places; the Iowa list is a useful second check.

Native species: 21 Typical Iowa county: 44 (median of 99 counties)
Garden-ready natives: 8 Typical Iowa county: 24
Share by type (all 21 native species): Percent of the 21 native species in each growth type

Wildflower (forb) 38% (8)
Grass or grass-like 10% (2)
Fern 52% (11)

Ferns make up the largest share of the native list (52%), followed by wildflowers (38%).

Recorded native ranges can include long-established populations that spread from gardens; check your state’s native plant society list for local guidance. How native status is decided.

ZIP codes mainly in this county fall in USDA hardiness zones 4b to 5a (2023 map).

The native plant list

Garden-ready natives 8

Native species with PLANTS growing records (height, light, moisture, minimum temperature). “—” means PLANTS has no value.

Garden-ready native plants of Delaware County, Iowa
Plant	Type	Height	Light	Water use	Hardy to
field horsetail Equisetum arvense	Fern	11 in	Sun–part shade	High	Zone 3a
nodding beggartick Bidens cernua	Wildflower (forb)	3.2 ft	Sun–part shade	High	Zone 12a
northern maidenhair Adiantum pedatum	Fern	1.3 ft	Shade-tolerant	Medium	Zone 3b
rattlesnake fern Botrychium virginianum	Fern	1.4 ft	Shade-tolerant	Medium	Zone 3b
sideoats grama Bouteloua curtipendula	Grass or grass-like	3 ft	Sun	Medium	Zone 3a
smooth horsetail Equisetum laevigatum	Fern	5 ft	Sun	Low	Zone 3b
water horsetail Equisetum fluviatile	Fern	3 ft	Sun	High	Zone 4a
wild sarsaparilla Aralia nudicaulis	Wildflower (forb)	1.5 ft	Shade-tolerant	Medium	Zone 3b

Other native species recorded here 13

PLANTS has no growing records for these, so light, moisture, height and zone filters cannot include them. Many are wild species seldom sold by nurseries.

bigbract verbena Verbena bracteata
bluejacket Tradescantia ohiensis
Carolina puccoon Lithospermum caroliniense
eastern marsh fern Thelypteris palustris
hairy woodland brome Bromus pubescens
hoary verbena Verbena stricta
northern selaginella Selaginella rupestris
sensitive fern Onoclea sensibilis
slender lipfern Cheilanthes feei
smooth cliffbrake Pellaea glabella
swamp verbena Verbena hastata
walking fern Asplenium rhizophyllum
western silver aster Symphyotrichum sericeum

Compared with Iowa

The typical county is the median of the 99 Iowa counties with PLANTS county records; the statewide figure counts every species native anywhere in the state. More species is not better or worse: counties differ in size, habitat and how thoroughly they have been surveyed.

Native species counts, Delaware County and Iowa
Measure	Delaware County	Typical county	Statewide
Native species	21	44	1,374
Garden-ready natives	8	24	496
Tree	0	—	110
Shrub	0	—	72
Wildflower (forb)	8	—	779
Grass or grass-like	2	—	298
Vine	0	—	55
Fern	11	—	60

Neighboring counties

Counties that share a ZIP code with Delaware County.

Buchanan County, IA 2 garden-ready
Clayton County, IA 24 garden-ready
Dubuque County, IA 12 garden-ready
Jones County, IA 9 garden-ready
Linn County, IA 11 garden-ready

Source & data date

Source: USDA NRCS PLANTS Database: county distribution records, native status and plant characteristics. CC0 (public domain dedication, per the data.gov catalog record).; Kew’s World Checklist of Vascular Plants (WCVP): native or introduced status by state. CC BY 3.0.; USGS US-RIIS (ver. 2.0): species listed as introduced are excluded. CC0.
Citation: USDA, NRCS. 2026. The PLANTS Database (https://plants.usda.gov, 11/04/2026). National Plant Data Team, Greensboro, NC USA.; Govaerts R. (ed.) (2026). WCVP: World Checklist of Vascular Plants. Facilitated by the Royal Botanic Gardens, Kew. Data file dated 2026-06-04, http://sftp.kew.org/pub/data-repositories/WCVP/ (retrieved 2026-11-04). Paper: Govaerts R. et al. (2021) The World Checklist of Vascular Plants, a continuously updated resource for exploring global plant diversity. Scientific Data 8, 215.
Data date: Retrieved from PLANTS on November 4, 2026; WCVP data file dated June 4, 2026.
Zones: USDA Plant Hardiness Zone Map (2023) ZIP table: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed November 3, 2026. Plant zones on this site are our estimate, not the official map.
Scope: Delaware County (county FIPS 19055), Iowa. 21 native species from PLANTS county distribution records; garden-ready = species with a PLANTS characteristics record.
Method: A species is listed when it is recorded as native to the state in Kew’s World Checklist of Vascular Plants and USDA PLANTS, and recorded in the county by USDA PLANTS. Species PLANTS labels both native and introduced are listed separately. Full method · All sources

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