Field Guide     Weed Management     Sweet Clover

Sweet Clover (Melilotus officinalis)

Crop Impacts: Pasture

Sweet Clover 1

About Sweet Clover:

Sweet Clover is a biennial or short-lived perennial weed that reproduces by the release of their seeds. As a native plant from Europe and Asia, Sweet Clover was brought to North America for forage, honey production and soil enhancers, and rapidly posed a problem for land management.

Family: Leguminosae family

Sweet Clover 2 Sweet Clover 3

Sweet Clover Scouting and Prevention:

The Sweet Clover has a strong and deep taproot that creates a plant that grows from 5 to 6.5 feet tall with many branches. The leaves are serrated around the edges, and have 3 oblong leaflets to them. Sweet Clover also produces a lot of small yellow or white flowers that sit in long loose flower arrangements. The seeds of this weed are plum shaped and wrinkled. At full maturity the seedpods are brown, dark gray or white containing 1 to 2 seeds.

Common locations

  • - Agronomic crops
  • - Grain fields
  • - Calcareous or loamy soil
  • - Pastures

Prevention

Prevention of Sweet Clover is less expensive and less time-consuming than trying to control it. Make sure when you are seeding a new area you are doing so with certified weed-free seeds. If there is an infested area on your property, be sure to drive around, instead of through it. Finally, make sure to give all equipment that has been in infested fields a good clean, to make sure no seeds are transferred.

Sweet Clover Control:

Cultural Control

If you are dealing with small amounts of Sweet Clover it can be controlled by hand removal in late fall after its first year of growth. Another time to hand pull these weeds is in its second year of life in May or June, before the plant has time to flower. Note it is much easier after rainfall when the soil is wet and loose. It is important to scout regularly, removing any new individual weeds.

Chemical Control

Herbicides can be a useful controlling method if you apply 2,4-D in spring, before native vegetation has emerged. If you are looking for a herbicide that will work well on seedlings and has little drift, a combination of 2,4-D plus Dicamba, which is a 1% solution of Mecamine, gets the job done.

Latin / Alternative Sweet Clover names:

  • - Melilotus officinalis

Additional Sweet Clover Resources

http://www.omafra.gov.on.ca/english/crops/facts/04-057.htm#sweet

http://www.omafra.gov.on.ca/english/crops/facts/cover_crops01/sweetclover.htm

http://sewisc.org/invasives/invasive-plants/43-sweet-clover

http://mdc.mo.gov/your-property/problem-plants-and-animals/invasive-plants/white-and-yellow-sweet-clover-control