White Clover in GrassClover in a grass hay stand is not always a problem, as many growers value it for nitrogen fixation, protein content, and forage quality. However, when clover begins to dominate, it can reduce grass stand longevity, shorten productivity, and create concerns for livestock, such as bloat in cattle.

If you plan to overseed grasses, it’s important to manage the clover first. Simply adding more seed without reducing the clover will likely fail, since clover competes aggressively for light, soil moisture, and nutrients.

The best time to control clover is during its vegetative stage before flowering and seed set. Once clover blooms, it can reseed aggressively, making control much harder. At the vegetative stage, clover is actively growing and most responsive to management. Options such as grazing, mowing, or herbicide application are most effective before bloom. Cutting or grazing early also reduces competition and improves conditions for successful grass overseeding.

  1. Spring or early summer control: Manage clover before bloom to give grasses a better chance to compete.
  2. Fall control: After the last cutting or grazing, before dormancy, can also be effective and set up grasses for stronger establishment the following season.

Research shows that managing competition well ahead of seeding with methods like mowing, grazing, or carefully timed herbicide applications gives new grass the best chance to establish in the stand. Once clover growth is checked, overseeding grasses will stand a much better chance of survival and long-term stand longevity, helping you maintain a balanced and productive hay field.

References

  1. Fery, M., Ghajar, S. M., & Smith, E. (2024, August). Revitalizing your pastures: A primer for overseeding pastures in Western Oregon. Oregon State University Extension Service. 
  2. Lingenfelter, D. (2024, August). Fall weed control in forages. Penn State Extension.  
  3. Fike, J., & Flessner, M. (2024, October). No-till seeding of forage grasses and legumes (SPES-92P). Virginia Tech School of Plant and Environmental Sciences. 
Waaswa, A. 2025, My seven-blend grass hay stand is infested with clover. Do I need to overseed it or control the clover first, and if so, should I wait until it blossoms?, Extension, University of Nevada, Reno, FAQ

Extension Associated Contacts

Andrew Waaswa
Andrew Waaswa
 

Also of Interest:

 
Cloverbud 4-H Record Book
Record Book for all "Cloverbud" project members (ages 5-8), with the exception of Horse Cloverbud projects.
 Washoe County Extension 4-H team 2022, Extension- University of Nevada, Reno forms
Growth performance and carcass traits of steers finished on three different systems including legume–grass pasture and grain diets Fruet, A.P.B; Stefanello, F.S.; Trombetta, F.; De Souza, A.N.M.; , Rosado Júnior, A.G.; Tonetto, C.J.; Flores, J.L.C.; Scheibler, R.B.; Bianchi, R.M.; Pacheco, P.S.; De Mello, A. S.; and Nörnberg, J.L. 2018, Animal
Weak and thin alfalfa stand
Overseeding Options for Reviving Thin Alfalfa Stands
Worried about thinning alfalfa? Learn when and how to overseed with grasses, legumes, or cereals to boost yields, improve forage quality, and extend stand life. This guide breaks down options, planting rates, timing, harvest tips, and practical management considerations.
 Waaswa, A. 2025, Extension, University of Nevada, Reno, Blogs