Your lawn starts with soil. Without quality soil, Pete says, you will never have a beautiful lawn. So what’s the best kind soil to have?
Pete says the best soil is pH neutral, that is, soil that’s in the 6 to 7.5 range on the pH scale. “You want to be balanced, just like your tap water is balanced, right around that 7 range.”
He first recommends testing your soil to see where on the pH spectrum you fall. Rob adds that most Pacific Northwest soil is on the acidic side, due to decomposing plant material.
One way to test your soil is by going through the local cooperative extension office. “These are independent labs; they will inexpensively test your soil for around $10,” Pete says. The phone numbers for the cooperatives can be found at the bottom of this article.
Next, Pete says, you have to think about your lawn. “Your lawn, really, is just like any other plant, except there’s lots of it,” he says. “Every plant, for nutrients, needs three things: nitrogen, phosphorous, and potash.” These components are often abbreviated as N, P and K on fertilizer bags.
These tie closely into the pH of your lawn. If your lawn is acidic, or 0-6 on the pH scale, you need to make it more alkaline, or move it toward 7, which is pH neutral.
One way to make your lawn more alkaline is by adding limestone. This comes in two varieties: calcium carbonate, which is the familiar white powder, or dolomitic limestone, which has a magnesium additive. These can either come in a fine powder, which is faster-acting, or a pellet. These can both be spread with a spreader.
If you soil is alkaline, move toward the sulfurs. Pete recommends using 2 pounds per 100 square feet. Other products, like acidifying fertilizers that contain ammonium nitrate, can pose environmental hazards.
The next step to green up your lawn is to aerate. Pete says typically this should be done in the fall, but it’s not terrible to do it in the spring.
Why should you aerate your lawn? “The point is to have oxygen and moisture get down into the root system,” Pete says. If you haven’t aerated your lawn but then fertilize, the top of the grass will grow quickly, but have a weak root system. If there is a dry summer, the roots will not have enough moisture, and your lawn will brown. In the fall, moss will grow.
If you don’t want to aerate your lawn using a rental, Pete recommends hiring a landscaper to do it for you.
As spring draws into summer, the noxious dandelion will soon sprout up all over your yard. Pete says if you haven’t been infested yet, spray a pre-emergent herbicide on your lawn as a preventative measure. If they have cropped up, spray with a post-emergent formula.
When you start thinking about fertilizing your lawn, which Pete says should happen in late May or early June, look for a 20/20/10 or a 20/10/10 fertilizer.
Those three numbers represent the percentages of nitrogen, phosphorous, and potassium. They work together to make your lawn the best on your block. Nitrogen is food for your lawn, which makes your grass grow lush, leafy, and green. Phosphorous makes your roots grow deep, giving you a strong root system. Potassium strengthens your roots, making them resistant to drought.
Finally, Pete recommends walking your sprinkler system to familiarize yourself with the locations of the heads so you don’t hit one with your mower. Then, prime your sprinkler system. Pete also says not to start watering your lawn until late May or June; the Pacific Northwest is still receiving a lot of rain.
Seattle Cooperative: 206-205-3100
Snohomish County Cooperative: 425-357-6003
Pierce County Cooperative:253-798-7180