To effectively kill annual knawel, a two-step approach is recommended: applying a preemergent herbicide in late summer or early fall, and spot treating actively growing weeds with a liquid, selective, postemergent, broadleaf weed killer in the spring.
1. Preemergent Application:
Late summer or early fall is the optimal time to apply a preemergent herbicide to prevent winter annual knawel from germinating. Preemergent herbicides work by creating a barrier in the soil that inhibits weed seed germination. It is important to apply the preemergent before the knawel seeds have a chance to sprout.
Here are the steps to follow for applying a preemergent herbicide:
1. Prepare the area: Remove any existing weeds or debris from the area where you plan to apply the herbicide. This will ensure better herbicide penetration and effectiveness.
2. Read the label: Always read and follow the instructions on the herbicide label carefully. Different herbicides may have specific application rates and timing.
3. Apply the herbicide: Use a spreader or sprayer to evenly distribute the preemergent herbicide over the desired area. Make sure to cover the entire area where knawel seeds may be present.
4. Water the area: After applying the herbicide, water the area lightly to activate the herbicide and help it penetrate into the soil. Follow the instructions on the herbicide label for specific watering recommendations.
It’s important to note that while a preemergent herbicide will effectively prevent knawel seeds from germinating, it will also prevent grass seed from germinating. If you are planning to sow grass seed in the same area, it’s best to choose an alternative approach or delay grass seeding until the following season.
2. Postemergent Spot Treatment:
In the spring, when knawel has already emerged and is actively growing, spot treating with a liquid, selective, postemergent, broadleaf weed killer can help control the weed. This type of herbicide targets broadleaf weeds while sparing grasses.
Here is how you can effectively spot treat knawel:
1. Identify the weed: Familiarize yourself with the appearance of knawel. It typically has small, oval-shaped leaves and stems that spread out close to the ground. Referencing pictures or plant identification guides can be helpful.
2. Choose the right herbicide: Select a liquid, selective, postemergent, broadleaf weed killer that is labeled for use on knawel and safe for your specific grass type. Make sure to read and follow the instructions on the herbicide label.
3. Spot treat the weeds: Using a sprayer or a sponge applicator, apply the herbicide directly to the knawel plants, taking care to avoid spraying or touching desirable plants. Be thorough, making sure to cover all visible parts of the weed.
4. Follow up as needed: If any new knawel plants emerge, repeat the spot treatment process until the weed population is under control. It’s important to treat the weeds before they go to seed to prevent further spread.
It’s worth mentioning that maintaining a healthy and dense lawn through proper lawn care practices, such as regular mowing, watering, and fertilizing, can help suppress weed growth, including knawel. Additionally, overseeding bare or thin areas of the lawn can help fill in gaps and prevent opportunistic weeds from taking hold.
Killing annual knawel requires a two-step approach: applying a preemergent herbicide in late summer or early fall to prevent germination, and spot treating actively growing weeds with a selective postemergent herbicide in the spring. Following proper lawn care practices can also help prevent weed infestations and promote a healthy lawn.
