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All About Black Medic

Chances are you’ve seen the Black Medic weed hanging out near a sidewalk or in a dead patch on your lawn, but do you know how it got there? Our comprehensive guide to this pesky variety of weed will help you identify and eliminate it in no time.

Keep reading to learn more about the characteristics of the Black Medic.

Black medic flowers in the field

History Of The Black Medic

The Black Medic’s scientific name is Medicago Iupulina. However, it’s also commonly known as the Yellow Trefoil, Yellow Clover, Black Clover, and Hop Medic.

Native to Asia and Europe, this type of weed is now commonly found in southern parts of Canada and the United States.

How To Identify the Black Medic

Black medic flowers in the field

Black Medic is also known as Yellow Clover because of the yellow flowers it produces. Given its distinctive features, the Yellow Clover weed is easy to identify!

Yellow Clover has hairy, oval-shaped leaves with toothed edges that appear in threes. This trait is common among many types of clover and is also why this weed type is often called the Yellow Trefoil.

In addition, Black Medic has small, round, yellow flowers at the end of its stems. These flowers are made up of tiny petals that turn into kidney-shaped fruits once they’re pollinated.

Rather than taking root as many separate Black Medic plants, there’s one main root structure, or taproot, from which many smaller stems grow.

Black Clover weeds grow horizontally, also known as growing prostrate. Because of this, they remain very close to the ground, which creates dense clusters.

Black Medic is found in various landscapes across the United States. It’s most common in residential areas like lawns and gardens and frequently pops up on the side of the road or directly next to sidewalks.

This weed variety can be found in agricultural areas like pastures and crop fields and in grasslands.

Why is the Black Medic Considered a Weed?

Black Medic is officially classified as a winter or a summer annual. However, in some areas of the United States with milder off-seasons, it may persist continually for up to a few years. This phenomenon is also known as a short-lived perennial.

Aside from its growing schedule, the Black Medic is primarily known as a weed because it both indicates and promotes poor soil quality.

Poor soil quality can occur due to a variety of factors like improper nutrients (specifically not enough nitrogen), irregular mowing, and compaction or poor aeration of the soil.

What Issues Does the Black Medic Cause?

Black medic (Medicago lupulina)

When soil quality is poor, Yellow Clover sneaks in and saps up the remaining nutrients, making it hard for grass and other plants to grow in the area.

This means that the Black Medic pushes existing grass out of the surrounding area and takes over weak grass.

It does so by hogging the existing nitrogen in areas where nitrogen in the soil is already scarce.

How Does This Weed Spread?

The Black Medic weed spreads easily through its seeds, which turn black and drop off the flower head and onto the ground at the end of the growing cycle.

The seeds are pretty hearty, so they can last on the ground throughout the winter once they’ve dropped off the stem.

If left untreated, new stems will continue sprout from the taproot and grow across land.

How to Get Rid of the Black Medic

There are many ways to deal with this variety of weeds that are gentle and effective! Because whatever you use to kill the weed will also impact the already unhealthy soil around it, we strongly recommend trying out some natural solutions first.

Yellow flowers of a black medic plant, selective focus with green bokeh background - Medicago lupulina

Natural Solutions

Given the fact that the appearance of Black Medic is caused by nutrient-poor, compacted soil, a natural solution is also the easiest one. If you can get the soil back to a healthy baseline, the Black Clover weeds will likely start to disappear by themselves.

One tactic you can take is aerating the soil using an aerator. Similarly, regularly mowing the affected patch of grass should also be successful. Just make sure that you don’t mow the grass too short!

Paying attention to fertilization and irrigation of the soil is another good practice. Apply nutrients and other organic materials to the soil so that it remains healthy and well-balanced. Water the area regularly, but not too much!

If you want to literally get to the root of the problem, you can also pull the Yellow Clover weeds by hand.

It may be hard to locate the roots because Black Medic only has a single large taproot.

However, pulling these weeds is often highly effective because getting the central root system out of the ground will eliminate large sections of the weed at a time.

Sprays and Weed Killers

If none of the natural solutions do the trick, you can apply a non-selective weed killer or suppressant to the affected area.

However, using an artificial spray will damage the already weak grass surrounding the weeds if you’re not careful with your application. Therefore, ensure you’re only spraying in the exact area where the weed is growing.

Applying a killer or suppressant is the better technique for particularly large areas of Black Medic weed that have gotten out of control. As a result, you may want to skip directly to this option if you’re dealing with an especially unwieldy patch of Yellow Clover.

Learning about Black Medic

The Black Medic is a fairly typical weed variety you’ve probably seen without even realizing it. Now that you know what the Black Medic is like, you can keep it out of your yard and have healthy grass all year round.

If you feel like you need to learn more about these pesky garden tenants, check out our weeds page to learn all about different weed varieties, treatment options, and surprising information.