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Eventually weeds will be a problem in every lawn. Keeping your lawn lush and healthy helps choke many weeds out. If you do get a weed infestation, take quick action. Once a weed population spreads, it is more visible in your yard and harder to eradicate. Moreover, in the Pacific Northwest, moss can also be a problem in your yard – especially in shadier areas.

Hiring a company to do a quarterly lawn weed and feed spray service is the easiest way to win the battle against weeds in your lawn. If you are a “do-it-yourselfer,” below are some tips to follow based on the type of weeds in your lawn.

Weed Identification

The first step in treating your particular weed problem is to first identify the type of weeds you need to treat. Most weeds in western Washington fall into three main categories – broadleaf, grassy, or annual.

Some gardeners also classify clover invasions in lawns as a separate category because there are specific products designed to kill just clover. Washington State University has published a quick guide to identifying and controlling weeds common to the area. You can download the file here.

Broadleaf Weeds

Broadleaf weeds are the easiest to identify in your lawn because they look the least like the rest of the grass. The most common types of these weeds include buttercup, dandelion, chickweed, plantain, speedwell, and many others. Broadleaf weeds have leaves that are larger in size and different in shape from a grass that has a long thin blade.

Killing broadleaf weeds is accomplished easily with any generic broadleaf weed killer. Many of these are pre-mixed so you just need to buy the bottle and spray. If the infestation is minimal, manually pulling the weeds themselves may be the best course of action. That prevents the runoff of the weed killer from entering the sewer systems. There are many new and inventive tools available from the local hardware store to make this chore go much more smoothly.

If your lawn has been infested with many weeds, consider using a granular “weed and feed” fertilizer that applies an herbicide along with fertilizer to help improve the thickness of your lawn. Remember to apply weed control products according to the label or you risk decreasing effectiveness of your applications.

Annual Weeds

Some weeds, like those in the “annual” classification for the Pacific Northwest, are a particular problem with newly planted lawns. Pre-treating the soil before planting grass can go a long way to prevent infestations from taking hold. Strong maintenance practices after planting should minimize the risk of these returning each year. There are a number of examples of these weed varieties, including henbit, lamb’s quarter, mallow (also called “cheeseweed,” “buttonweed,” or “wild hollyhock”), and pigweed are some common types.

Pulling weeds from the lawn as often as possible is the best method to treat problem areas. However, commercial herbicides may be needed to control problem infestations. Follow the instructions carefully to minimize damage to other plants. In this weed control guide, Washing State University has specific chemical recommendations for each weed type. As an alternative, take a sample of the problem weed to your local home and garden center for help in selecting the right product for your problem.

Grassy Weeds

There are many grassy weed invaders that affect lawns in the Pacific Northwest, like the crabgrass pictured above. Other weeds of this category include annual bluegrass, bentgrass, pasture grass, Bermuda grass, quackgrass, and others.

Some grassy weed invaders need warm, dry conditions to thrive and many die out with the first frosts of winter. Be careful to ensure that your existing lawn doesn’t become “taken over” by larger infestations while waiting for the weather to change. Other grassy weeds can be eradicated by proper mowing to clip the weeds at a point where seeds can no longer germinate. Some heavier infestations may need to be treated with a commercial herbicide or “weed and feed” product.

As always, be sure to select the right type of herbicide product for your particular weed infestation and follow the directions carefully. Because grassy weeds are of the same family as your actual lawn, killing the weeds with herbicide can damage the surrounding grass. You may need to re-seed or sod bare spots of the lawn damaged in the weed control process. Also check that you’re watering and mowing your lawn properly to ensure the best growth and prevent the grassy weeds from returning.

Moss in the Lawn

Lawn moss is a problem common to the Seattle area because of the rainy weather. Moist soil doesn’t always have the opportunity to dry out in between storms, leading to perfect conditions for moss in the soil to grow. Moss is spread by spores produced from individual leaves that are disbursed through rainwater or other moisture. Attempting to “rake out” moss from your lawn will only spread these spores to other areas.

For the initial treatment of lawn moss, using a chemical herbicide is recommended. Apply moss control in the spring and then remove the brown residue of dead moss with a rake.

Improving the ability of the soil to dry out is the best way to prevent moss from returning. Improving drainage through aeration, avoiding over-watering, decreasing shade, and regular feeding are the best ways to prevent the moss from returning.

Note that areas of your lawn that are primarily shaded will have increased issues with moss. Planting flowers at the bases of trees, for example, may be needed if lawn moss continues to be a problem.