How To Keep a Green Lawn in the Pacific Northwest

Dig a 6-inch hole in the yard to collect soil samples from the bottom of the hole. Place 1/2 cup of soil in a sealable container and mail to your nearest cooperative extension office. Both Washington State University and Oregon State University offer soil tests. When you mail in your soil or drop it off, these cooperative extension offices conduct soil tests and mail you the results. The results will indicate what type of fertilizer to use and if you need to make soil amendments.

Spray a selective herbicide in the early spring to remove weeds in the yard. Lawns generally need mowing in the beginning of their growing season in April in the Pacific Northwest. To keep weeds from stealing the soil's nutrients and crowding out your grass, spray a selective herbicide that is safe for your grass type in late February. Weeds use nitrogen in the soil to grow. Nitrogen is one of the essential nutrients for you grass to maintain its green color; therefore, it is essential to remove weeds before the grass starts growing.

Scatter grass clippings throughout the yard after mowing. Grass clippings contribute a great source of nitrogen to the soil. You can distribute clumps of grass clippings by raking them over the yard.

Pour 1 lb. of slow-release nitrogen fertilizer into your rotary drop spreader to distribute every 1,000 square feet. According to Oregon State University, gardeners should apply their lawn's fertilizer in April after the grass has had time to green up. Applying fertilizer before the grass has started growing will encourage weed growth.

Water your lawn with up to 1 inch of water every week during June through August as suggested by Oregon State University. By keeping the ground moist, you encourage a green lawn in the warmest time of the year in the Pacific Northwest.