Black Medic Guide

Adopt a Consistent Lawn Care Routine

If you've noticed Black Medic in your lawn or garden, you might be wondering how to prevent it from coming back. Maintaining a healthy lawn through a consistent lawn care routine is key to keeping weeds at bay.

Also known as hop medic or black clover, Black Medic thrives in dry, compacted soil with low nitrogen. Improving your lawn's overall health through proper fertilization, irrigation, and aeration, along with pre-emergent herbicide applications, can significantly reduce weed growth.

Follow the tips below to ensure your lawn stays healthy and to prevent Black Medic from returning.

How to Apply Granular Lawn Fertilizer

Black Medic and other legumes, like white clover, have the ability to fix their own nitrogen, which is why these low-growing weeds often thrive in areas with insufficient nitrogen levels. To prevent Black Medic from taking root in your turf, the key is to follow a fertilization plan that ensures your soil receives the correct amount of nitrogen.

Begin by performing a soil test to assess the nutrient levels in your lawn. A soil test not only reveals the amounts of nitrogen, potassium, and phosphorus in your soil but can also help identify potential issues, such as pH imbalances. Once you understand what nutrients your lawn is lacking, you can apply the appropriate fertilizers and amendments to improve soil health. This will promote stronger grass growth and help reduce the likelihood of weed invasions in unhealthy turf.

With the necessary fertilizer NPK ratio in mind, use our fertilizer selector tool to find the ideal product for your lawn.

How to Aerate Your Lawn - Tips for Lawn Aeration

If your soil is difficult to work with, it may be necessary to reduce compaction and improve irrigation. Black Medic tends to thrive in areas where the soil is dry and compacted, often seen near sidewalks, driveways, curbs, and other areas where the soil is tightly packed.

Soil compaction limits root growth and reduces the movement of water, causing water to pool on the surface rather than being absorbed by the soil. This can hinder your grass and other plants from taking in the water and nutrients they need.

Aerating your lawn to alleviate compaction, ensuring proper drainage and irrigation, and maintaining healthy mowing practices will help keep your lawn vibrant and robust. A healthy lawn can outcompete Black Medic and other weeds.

Explore these resources for more tips on maintaining a healthy lawn throughout the year:

Grass Care Guides
Lawn Care Schedule for Cool-Season Grasses
Lawn Care Schedule for Warm-Season Grasses

How to Apply Pre-Emergent Herbicide in Split Applications

While good cultural practices can give your lawn a strong defense against weeds, applying pre-emergent herbicides (weed preventers) in both the spring and fall is a critical step to stop Black Medic from spreading.

Pre-emergent herbicides containing dithiopyr or isoxaben are particularly effective at preventing Black Medic growth.

When to Apply Pre-Emergents

Black Medic can act as both a summer and winter annual weed, germinating from seeds when soil temperatures warm in spring or cool in fall. To be effective, pre-emergent herbicides must be applied before the seeds germinate.

• Spring Application: Apply pre-emergents after the soil thaws but before soil temperatures reach 55°F. This timing helps prevent other weed seeds from germinating.
• Fall Application: Apply as soil temperatures cool to 70°F for effective control of winter-germinating seeds.

Split-Application Strategy

For better coverage and control, consider a split-application approach:

• Apply the pre-emergent herbicide twice in the spring, spaced 6-8 weeks apart.
• Repeat the process in the fall with two additional applications, also spaced 6-8 weeks apart.

Timing between applications can vary depending on the product used, so always refer to the product label for specific usage rates and detailed instructions.