Photos and descriptions of Black medic Have you found Black Medic in your lawn? Learn more about how to identify this weed, what conditions cause it and the best ways to remove and prevent it in the future. Hi all! I’m a newbie gardener who has inherited a jungle of a garden in my recent house move.
Black medic ( Medicago lupulina )
Black medic is a low-growing summer or winter annual broadleaf plant that sometimes behaves as a short-lived perennial. It is found throughout California, except for deserts, to about 8200 feet (2500 m). Black medic is common in turf and inhabits agricultural land and disturbed areas. It is good forage for livestock and sometimes is cultivated for pasture or as a cover crop. However, black medic seed is a common contaminant in commercial alfalfa and clover seed.
Grassland, pastures, vegetable and agronomic crop fields (especially alfalfa), orchards, vineyards, gardens, lawns, roadsides and other disturbed, unmanaged places.
Cotyledons (seed leaves) are oblong, smooth, and about 1/6 to 1/3 of an inch (4–9 mm) long. The first leaf is oval and broader than it is long, with a smooth edge. True leaves are fully subdivided consisting of three egg-shaped leaflets with toothed edges and resemble leaves of the mature plant.
The main stem branches near the base. Stems grow prostrate or prostrate with tips pointing upward and can reach 1-1/3 feet (40 cm) long. The plant is hairy, especially the stems. Leaves are alternate to one another along the stem. Leaves are fully divided into three egg- to heart-shaped leaflets with somewhat toothed edges. Leaflets are about 2/5 to 7/10 of an inch (1–2 cm) long and finely toothed at the tip, which often bares a tiny, slender tooth. The stalk of the middle leaflet is longer than those of the lateral leaflets. Black medic is distinguished from California burclover by its hairy leaves; the latter has nearly hairless leaves. Also the small leaflike structures (stipules) at the bases of leaf stalks are not deeply lobed and have smooth edges or a few shallow teeth in black medic, whereas those of California burclover are deeply lobed, slender and curved.
Flowers bloom from April through July. Usually ten to twenty yellow, slender, pealike flowers densely cluster to form a rounded flower head.
Fruits are kidney-shaped pods about 1/12 to 1/8 of an inch (2–3 mm) long, strongly veined, and black at maturity. Each pod contains one seed, but does not open to release seeds.
Seeds are oval to barely kidney shaped, smooth, yellowish to olive green, about 1/12 of an inch (2 mm) long, and have a small sharp point on the concave side.
Black Medic, also known as Medicago lupulina or Yellow Trefoil, is a Summer annual weed. This means that it germinates sometime in the late Spring, grows well during the heat of Summer, then dies off with the cold weather. Black Medic is sometimes referred to as Yellow Clover because it looks like Clover with teardrop-shaped leaves, but has a yellow flower. The seed pods of Black Medic are also unique. They turn black when they’re ready to drop. If you can remove the Black Medic before this happens, it will help eradicate the plant, as the seeds are its only way of reproducing and they can stay viable for years and throughout Winter.
What Causes Black Medic?
It’s important to understand the conditions needed for Black Medic to thrive. A little Black Medic is normal. It will fill in the bare areas during the heat of Summer. A lot of Black Medic however, typically indicates that your lawn is being mowed too short in the Spring and Summer, your grass types are not strong or healthy enough to compete with the weed or your soil is compacted. If you notice the Black Medic growing by the roadside or next to a sidewalk, this is a sign that your soil quality is compromised due to foot traffic and compaction is the underlying problem.
How To Get Rid Of Black Medic?
Since Black Medic has a short lifespan, the bulk of your effort should go towards improving your lawn to prevent this weed from populating the following year. But there are a few things you can do to eliminate the weed right away.
- Pick the Black Medic. If you’re able to do this when the soil is wet, that would be ideal, as the roots will more easily and cleanly pull out of the ground. Black Medic grows out of a central location, so hand weeding can be very effective for removing the weed from large areas.
- Another option for elimination is to use a natural weed suppressant, such as Weed Beater Fe, which will be successful in killing the weed, however it also causes stress on the surrounding grasses, so use it sparingly.
How To Prevent Black Medic?
Black Medic and other annual weeds will emerge where your lawn is not competing. It could be that you’re mowing your lawn too short, which is keeping your grasses from growing stronger than your weeds. It could also be that the grasses you have are too weak and old and just don’t fight that well. Another option is that you have dry, compacted soil. Luckily, there are several ways to address the issues that could be resulting in the Black Medic in your lawn.
- One of the worst things you can do for your lawn is remove too much of the grass blade in a single mowing. Removing more than 1/3 of the grass blade length in a single mowing will turn the grass brown, stop root growth, and invite in weeds. So set your mower blades high.
- Dull mower blades are another common mowing issue because they rip the grass, instead of cutting it. This leaves your lawn vulnerable to disease and weeds and also dehydrates the grass blades, causing them to turn brown. A hardware store should be able to sharpen your blades for you. Try to do this every 20 hours worth of cutting or at least once per season
- If you have older poor grasses, a total Lawn Renovation might be the best choice.
- If you don’t want to go that far, simply Slice Seeding your current lawn should make a big difference.
- Given that compacted soil is an ideal environment for Black Medic to grow, we recommend aerating your soil. You can do Core Aeration or Liquid Aeration. If you’d like a DIY solution for aeration, try Liquid Aerator on the areas where you’re noticing the problem.
- Lastly you can try our Organic Soil Builder application, which will add valuable organic matter and nutrients to your soil, serving as an organic fertilizer that will promote healthy and balanced grass growth.
Contact us to learn more or to get our opinion on what would be best for your specific situation.
Weed with black pods
Hi all! I’m a newbie gardener who has inherited a jungle of a garden in my recent house move. Please could anyone help me identify a weed with black pods which has spread rapidly in my front garden? The pods are shooting seeds across the plant beds so it’s growing quickly. I am currently trying to get rid of it but worried that it will continue to come back as I cannot identify a root. Any help will be greatly appreciated!
Lots of plants have black pods. Can you do a photo, or a fuller description, shape of leaves, colour of flowers, height, any else about it
I have photos but not sure how to upload it to this forum? It has long arching stalks that are tangled between all the other plants and small (elongated oval) leaves.