Fern · Equisetaceae
Smooth horsetail
Equisetum laevigatum
Smooth horsetail is recorded as native to 28 states and territories in Kew’s World Checklist of Vascular Plants and USDA PLANTS, and recorded in 853 counties of those states by USDA PLANTS.
Key facts · USDA PLANTS
Smooth horsetail at a glance
- Native in
- 853 counties, across 28 states and territories
- Estimated cold hardiness
- Zone 3b PLANTS minimum temperature −38°F
- Mature height
- 5 ft PLANTS mature height
- Light and water
- Full sun (shade-intolerant) Low water use
Estimated cold hardiness: zone 3b. PLANTS gives a minimum temperature of −38°F; zone 3b winters bottom out at −35°F, the coldest half-zone that stays within that limit.
Smooth horsetail is recorded as native to 28 states and territories in Kew’s World Checklist of Vascular Plants and USDA PLANTS, and recorded in 853 counties of those states by USDA PLANTS.
Counties where it is native
The 15 counties with the most ZIP codes among the 853 where it is listed.
Native counties by state
- Arizona 8 counties
- Arkansas 1 county
- California 47 counties
- Colorado 40 counties
- Connecticut statewide record
- Idaho 23 counties
- Illinois 76 counties
- Indiana 34 counties
- Iowa 74 counties
- Kansas 58 counties
- Minnesota 71 counties
- Missouri 19 counties
- Montana 7 counties
- Nebraska 57 counties
- Nevada 15 counties
- New Mexico 14 counties
- New York 18 counties
- North Dakota 39 counties
- Ohio 23 counties
- Oklahoma 21 counties
- Oregon 24 counties
- Pennsylvania 3 counties
- South Dakota 21 counties
- Texas 37 counties
- Utah 29 counties
- Washington 23 counties
- Wisconsin 50 counties
- Wyoming 21 counties
Growing traits
Values from the PLANTS characteristics record. “Not recorded” means PLANTS has no value; nothing here is estimated except the zone.
Growth
- Growth habit
- Forb/herb
- Duration
- Perennial
- Mature height
- 5 ft
- Growth rate
- Rapid
- Growth form
- Single Crown
- Shape
- Erect
- Lifespan
- Moderate
- Active growth period
- Spring
Light and water
- Shade tolerance
- Intolerant (full sun (shade-intolerant))
- Moisture use
- Low water use
- Drought tolerance
- None
- Tolerance of waterlogged soil
- High
- Precipitation range
- 10 to 45 in per year
Soil
- Soil textures
- Medium and fine
- pH range
- 4.5 to 6.5
- Lime (CaCO₃) tolerance
- Low
- Salinity tolerance
- Low
- Fertility requirement
- Low
- Minimum root depth
- 10 in
Climate
- Minimum temperature
- −38°F
- Estimated cold hardiness
- Zone 3b and warmer
- Minimum frost-free days
- 90
- Fire tolerance
- High
Flowers, leaves and fruit
- Flower color
- Green
- Showy flowers
- No
- Bloom period
- Early Spring
- Foliage color
- Green
- Showy in fall
- No
- Keeps leaves
- No
- Fruit color
- Brown
Other
- Toxicity
- Moderate
- Nitrogen fixation
- None
- Nursery availability
- No Known Source
- Family
- Equisetaceae
- PLANTS symbol
- EQLA
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.
- Scope
- Equisetum laevigatum (PLANTS symbol EQLA).
- 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