February 18, 2016
February 18, 2016

Weeds are an annoying problem every homeowner faces. Both grassy and broadleaf variety of weeds can infest yards and turfs. Broadleaf weeds never merge well visually with existing grass and are difficult to mow and control.

Sweet clovers are one of the most common broadleaf weeds that pester homeowners. The sweet clover plant comes in two varieties, white sweet clover (Melilotus alba) and the yellow sweet clover (Melilotus officinals). Both varieties are quite invasive with the yellow one being most prominent.

In this article, we will see some facts about the sweet clover, and while we are at it, we will also see some tips to eliminate this weed.

What is Sweet clover?

Both the yellow and white sweet clover varieties are biennial leguminous plants. Both the plants are vegetative in their first year producing no flowers what so ever. The leaves of the sweet clover bear a characteristic ‘clover-like’ appearance.

In the second year of the growth, the plant appears prominently bushy with densely packed flowers on the top few inches of the elongated stem.

Interestingly, sweet clovers are indigenous to Europe and Asia and were brought to North America during the late 1600s. They were introduced as forage plants. Being leguminous, sweet clover fixes nitrogen in the soil and hence enriching the soil as they grow.

The plant prefers a loamy, calcareous soil and can tolerate partial shade.

How to manage Sweet clover?

Sweet clover infestation usually occurs during the late spring or early summer, and the plants put all their energy during the first year in developing a very robust root system.

The best way to control the weed and prevent its further spread by mechanical control during the first year of its growth cycle.

  • Small amounts of the weed present in your yard can be pulled out by hand with relative ease. If you want to pull them off in their second year of growth, the best time is May or June before the plant flowers.
  • Pulling should be delayed until the plants develop sturdy stems that will not snap when you try to pull the weed out. As the first year is strictly vegetative, waiting for the right time should not be a problem.
  • Even after the complete elimination of the weed by pulling it out, it is necessary to determine whether there is any fresh growth the following spring.
  • The individual sweet clover plants can be found scattered throughout the yard if the yard had been infected before. Make sure to get rid of each and every plant as quickly as you can before they have a chance to flower.
  • Regular applications of pre and post-emergent weed control products is recommended to battle bad outbreaks. Hiring a lawn care service that provides year-round protection is recommended as part of a broader weed control management program.

Something to take home

Sweet clovers, both white and yellow, can be a really troubling weed. Although they can fix nitrogen in the soil and enrich it, and hence have a specific benefit on uncultivated lands, they have no place in your turf.

On a side note, the drug Warfarin, used as a blood thinner, was first isolated from the sweet clover plant. Although the plant is no longer the source of the drug, it is still an interesting bit of information!