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Ohio State University Extension


Sweetclover as a Cover Crop in Ohio

Agriculture and Natural Resources
Sarah Noggle; Educator; Food, Agriculture, and Environmental Sciences; Ohio State University Extension, Paulding County
Rachel Cochran; Extension Associate, Water Quality; Food, Agriculture, and Environmental Sciences; Ohio State University Extension, Paulding County

Information gathered from the Midwest Cover Crops Council (MCCC) was used to compile this summary on how to use sweetclover as a cover crop in Ohio. For more information, see the Midwest Cover Crops Field Guide, Third Edition, and the Cover Crop Selector Tool found at: up of plants with long green stems and small, yellow flowers growing on the top of the stem.


  • Plant has serrated leaflet edges, three leaflets per leaf, and an extensive taproot.
  • White-flowered sweetclover (M. alba) is taller, coarser-stemmed, and has coarser leaves than the yellow-flowered type (M. officinalis).
  • Yellow sweetclover is more drought tolerant, more vigorous as a seedling, flowers earlier, and has spreading growth as compared to the white-flowered type.

Cultural Traits

  • Biennial or summer annual
  • Minimum germination temperature: 42 degrees Fahrenheit
  • Reliable establishment window (state average): Mar. 29–May 20: July 25–Sept. 6
  • Upright growth habit: 1.5–7.0 feet
  • Preferred soil pH: 6.5–7.5
Table 1. Rating the traits of cover crop sweetclover.
Heat tolerance Very good
Drought tolerance Excellent
Shade tolerance Good
Flood tolerance Very good
Low fertility tolerance Excellent
Winter survival Expected


  • Drilled at ¼–½ inch
  • 6–10 lb./acre (pure live seed)
  • Broadcast with shallow incorporation
  • 7–11 lb./acre (pure live seed)
  • Broadcast without incorporation
  • 8–12 lb./acre (pure live seed)

Additional planting information:

  • 258,600 seeds per lb.
  • Inoculation type: alfalfa, sweetclover.
  • Sweetclover may also be frost-seeded.
  • When planting on slopes or using for forage/grazing, increase seeding rate.
  • Broadcasting without incorporation is usually less dependable than drilling or broadcasting with incorporation.
  • When interseeding, time the seeding to match appropriate crop growth/maturity.

Disclaimer: Rules for Financial Assistance Program Recipients
Individuals participating in financial assistance programs are required to follow Natural Resources Conservation Service (NRCS) Appendix A regarding seeding rates and dates. Failure to do so will jeopardize payments. Appendix A can be found in Ohio’s Field Office Technical Guide, Section 4, Ecological Sciences Tools:


  • Dry matter = 3,000–5,000 lb. per acre, per year
    • Biomass quantity is highly dependent on planting/termination dates and precipitation.
  • Total nitrogen = 90–170 lb. of N per acre (not fertilizer replacement).

Additional performance information:

  • Deep-rooted after establishment
  • Contains coumarin; when moldy, turns into an anticoagulant than can harm or kill livestock
  • Bloat hazard
  • Slow to establish compared to other cover crops
  • Good for underseeding
  • Does not host soybean cyst, root lesion, and root-knot nematodes
  • Susceptible to damage from harvest wheel traffic and from being buried with residue
  • Host for bean yellow mosaic virus
Table 2. Rating the attributes of cover crop sweetclover.
Nitrogen source Excellent
Soil builder Very good
Erosion fighter Very good
Weed fighter Very good
Grazing Good
Quick growth Good
Lasting residue Good
Mechanical forage harvest Very good
Grain seed harvest Excellent
Cash crop interseed Good

Termination Information

  • Tillage
    • If terminating with only tillage, multiple passes are often required.
  • Chemical

Additional termination information:

  • Follow NRCS guidelines for cover crop termination dates to comply with crop insurance.
Table 3. Potential advantages of cover crop sweetclover.
Soil Impacts


  • Requires growth throughout the entire season
Frees phosphorus (P) and potassium (K) Excellent

Compaction fighter

  • Not as effective in a no-till system
Very good

Chokes weeds

  • Better at fighting weeds when established
  • Has shown allelopathic traits in second-year vegetative state
Attracts beneficials Excellent
Bears traffic Good

Potential Disadvantages

Delayed emergence: could be a major problem

Increased weed potential: could be a moderate problem

  • Hard seeds reseed.

Increased insects/nematodes: could be a moderate problem

Hinders crops: could be a minor problem

Establishment challenges: occasionally a minor problem

Mature incorporation challenges: could be a moderate problem


This publication was adapted with consent from the Midwest Cover Crops Council (MCCC) with content from the Midwest Cover Crops Field Guide, Third Edition, and Cover Crop Selector Tool ( It was created under a joint project with MCCC to produce customized introductory guidance about cover crops for all member states/provinces. Ohio cover crop recipes can be found at

The Midwest Cover Crops Council ( aims to facilitate widespread adoption of cover crops throughout the Midwest by providing educational/outreach resources and programs, conducting new research, and communicating about cover crops to the public.

Funding for this project was provided by the McKnight Foundation.

Red rectangle with white lettering spelling McKnight Foundation.



Originally posted Apr 6, 2023.