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All About Yellow Sweet Clover

Yellow Sweet Clover (also known as Ribbed Melilot) is a legume plant under the classification of Mililotus Officinalis. Sometimes used as additional feed for livestock, it is often classified as a weed.

Read on to learn more about this type of weed, including its problems, how to identify and get rid of it, and its medicinal benefits.

Flowers of yellow plant sweet clover officinalis close-up.

Why Is Yellow Sweet Clover Considered A Weed?

The Problem with Yellow Sweet Clover

Unlike many classified weeds, Yellow Sweet Clover’s problem extends beyond its encroaching tendencies. Although the plant is harmless when young and good for livestock feed or hay, it becomes problematic as it ages.

The stem toughens as the weed ages, making it far from an ideal haying product. However, the presence of a certain toxin called coumarin within the plant is more concerning. This compound is what gives the weed its bitter taste.

In small doses in the young legume, this toxin presents little danger. However, if the plant becomes heated or spoils, such as when exposed to mold fungus within a bale of hay, it is converted into dicoumarol. This toxin can interfere with the ability of an animal’s blood to clot properly.

Where Yellow Sweet Clover Comes From

Like many weed types, it’s not indigenous. It was imported from Europe and Asia.

How Yellow Sweet Clover Spreads

Yellow Sweet Clover spreads rapidly by the proliferation of its seeds and can often be found in uncultivated areas. Think roadsides, open fields, and more.

Yellow Sweet Clover is a biennial weed, meaning its growth happens in a two-year phase. The weed can be easily overlooked in the first year, as the plant remains just a few inches tall. But during that time, it’s setting down a powerful root system.

In the second year, the plant will put its effort into above-ground growth and begin seeding, making it even trickier to tame.

One of the most difficult things about this particular weed is that the seeds have incredibly long viability–some seeds can last for 30 years or more! This can make it difficult to tackle a Yellow Sweet Clover problem in your landscaping fully.

How To Identify Yellow Sweet Clover

Melilotus officinalis (Yellow Sweet Clover) isolated on white

The first trick to taming the presence of Yellow Sweet Clover on your property is learning how to identify it. This biennial legume is growing up to six feet tall and sporting a rough stem and toothed leaves. The flowers themselves are bright yellow and appear in layers.

How to Get Rid Of Yellow Sweet Clover

Melilot - yellow sweet clover. Thickets high yellow flowers on a background of green forest

Sprays and Weed Killers

Sprays and weed killers can be difficult to use against mature Yellow Sweet Clover. While a standard weed killer or farmland fumigation could do the trick, there may be some problems.

Removing the seeds is the key to routing the mature weed. This can be time-consuming and difficult since the seeds resist fumigation and solarization efforts.

Your best bet will typically lie in tackling the plants when young, generally in the first year before they begin to seed. Otherwise, care for them before the flowers bloom in the spring.


The good news is, when it’s young, Yellow Sweet Clover is not a terrifically difficult sort of weed to tame. In small quantities, hand weeding works well. Just be sure to pull up the entire root system so that it doesn’t have a chance to regrow!

For larger patches, the mowing also works well. However, you must mow and weed before the weed’s yellow flowers bloom. Otherwise, you will simply be scattering seeds while you work.

For farmers, allowing animals to free graze on young Yellow Sweet Clover is a great way to tame the spread of this weed. In this case, there is no need to worry about the toxin coumarin, as the coumarin will not be exposed to the mold fungus that comes with baled, wet hay.

Are There Benefits to Yellow Sweet Clover?

Beautiful sweet yellow four clover plumeria flower.

Medicinal Benefits

There are several medicinal remedies for which Yellow Sweet Clover is known. Native American tribes used Yellow Sweet Clover and partridge berry to create a natural fever reducer. On its own, an infusion of this weed was given as a cold remedy.

The coumarin within the plant is also used in herbal medicine to treat long-lasting headaches. It is also used to address soreness, tenderness, menstrual symptoms, and other signs of inflammation throughout the body.

Edible Uses

While it is still young, Yellow Sweet Clover has a few edible uses. The leaves are said to have a mild, almost vanilla-like flavor. They can be enjoyed in a salad, lightly boiled (for no more than five minutes), or even dried and crushed.

The seeds, meanwhile, are pea-like and make for a great seasoning in stews, soups, and various other dishes.

However, the edible uses for Yellow Sweet Clover expand far beyond the human spectrum. This weed is a fantastic pollinator–part of its scientific name Melilotus has its roots in the Latin word Mel, meaning “honey”. So it comes as little surprise that honeybees, butterflies, and other pollinators love this weed!

We have established that livestock ruminants such as cows and sheep love this wild legume. But they aren’t the only ones. Wildlife, including mule deer, elk, and even wild antelope, will graze freely on this plant.

Because it is highly drought and cold-resistant, Yellow Sweet Clover can boost protein and energy for these animals, particularly in more desperate feeding times.

Other Benefits

Another use Yellow Sweet Clover can claim, but which many weeds cannot, is that it is a nitrogen-fixing plant. This is because it is a legume. All legumes, like soybeans, green beans, etc., are nitrogen rich in and of themselves.

Thus, Yellow Sweet Clover can amend the nitrogen level and boost the health of the soil wherever it lives. For this reason, it has even been used as a cover crop by many farmers—likely contributing a good deal to its spread.

Wrapping Up Yellow Sweet Clover

Feeling ready to tackle the presence of Yellow Sweet Clover on your property? Before you get started, be sure to check out our Weeds page. This is a great resource to help you identify and effectively deal with all sorts of weeds that may present themselves in your area.