Updated October 19, 2026
The transition from winter to spring can be rough, but your lawn doesn’t have to be. In Western Washington, months of rain, shade, and cool temperatures often leave lawns thin, mossy, and matted by spring. A little work now sets your lawn up for a healthy summer. This process requires a few tools, but they’ll come in handy season after season.
Spring is a great time to clean up and feed your lawn. If you’re planning a larger overseeding project, keep in mind that early fall (roughly late August through September) is often the ideal seeding window in our region. Spring seeding works well too, as long as you’re ready to water consistently through the first summer.
What You’ll Need to Prepare Your Lawn For Summer
- A dethatcher or thatching rake
- An aerator
- A soil test kit (optional, but helpful)
- Fertilizer (a starter fertilizer if you’re seeding or your lawn is new)
- A fertilizer spreader
- Grass seed suited to the Pacific Northwest
- Topdressing material, such as compost, a compost-sand blend, or sand
- A spot shaker
Clear the lawn. Take a look at your lawn. If there are a lot of fallen leaves, pinecones, or dead grass clippings, rake them up before you begin. Debris blocks new seed from reaching the soil and shades out young grass, so a clean surface gives your seed the best chance to sprout.
Check for moss. Moss is one of the most common lawn problems in the Pacific Northwest. It thrives in shade, compacted soil, and acidic soil. If you see moss, rake it out or treat it with a moss-control product before moving on. Moss usually signals that something else needs attention, so it’s worth testing your soil and checking how much shade the area gets.
Dethatch your grass. Thatch is the layer of dead grass, roots, and debris that builds up between the grass blades and the soil. Dethatching pulls that layer out so water, air, and new seed can reach the soil. It might look like you’re beating up the yard, but you’re simply clearing space for healthy new growth.
Fertilize your lawn. If you’re seeding, use a starter fertilizer. It’s formulated to feed new grass without harming young seedlings. Avoid weed-and-feed products when seeding, because the weed control can keep new seed from growing. Check the back of the bag for the right spreader setting.
Topdress and seed. Spread grass seed at the rate listed on the bag. Using more seed than recommended can crowd seedlings and weaken them, and too little can leave patchy spots. Many homeowners mix seed with a light carrier, such as compost or sand, to help spread it evenly. [In our video, we used tube sand.] Use a spot shaker to work the mixture into the holes the aerator left. That gives the seed good contact with the soil and a little space for water to soak in.
Water new seed. Keep the top layer of soil consistently moist until the new grass is established. This usually means light watering once or twice a day for the first few weeks. Once the grass is growing well, switch to deeper, less frequent watering.
Keeping Your Lawn Healthy Through Summer
Western Washington summers are often dry for weeks at a time, so a few simple habits make a big difference.
Water deeply and less often. Established lawns generally need about an inch of water per week, including rainfall. Watering deeply in the early morning encourages deeper roots that handle dry spells better.
Mow a little higher. Taller grass shades the soil and holds moisture. Keep your mower set higher in summer, and avoid cutting more than one-third of the blade at a time. Sharp mower blades make cleaner cuts and help reduce stress on the grass.
Leave the clippings. Grass clippings left on the lawn break down quickly and return nutrients to the soil.
Know that brown isn’t always bad. Healthy, established lawns can go dormant in summer and green up again when fall rains return. If you’d rather save water, letting your lawn rest is a perfectly reasonable choice. Just avoid heavy foot traffic and skip fertilizer until it’s growing again.
It’s easy to overcomplicate lawn care, but a healthy lawn really just needs a little love, food, and the right timing. Follow these steps in spring, keep up with watering and mowing through summer, and you’ll be on track for a beautiful yard all season. To see this process in action, watch our video here: https://www.instagram.com/p/CcTxqd9ldnY/
Frequently Asked Questions About Lawn Care in Western Washington
Early fall is generally best, roughly late August through September. Warm soil helps seed germinate quickly, and returning fall rain keeps young grass watered while weeds slow down. Spring, from mid-April through May, also works, but new grass has less time to establish roots before dry summer weather arrives. If you seed in spring, plan to water consistently through the first summer.
Remove the moss, then fix the conditions that let it grow. Moss thrives in shade, compacted or poorly drained soil, acidic soil, and thin turf. Rake or dethatch out the moss, or treat it with a moss control product before raking. Then aerate, test your soil and adjust the pH if needed, and overseed bare spots with a shade-tolerant grass blend. Where shade is heavy, consider thinning tree canopy or using ground covers better suited to those conditions.
Most established lawns need about one inch of water per week in summer, including any rainfall. Water deeply and less often, ideally in the early morning, so roots grow deeper and the grass handles dry spells better. Frequent light watering encourages shallow roots. A simple way to measure is to set a few straight-sided containers on the lawn and time how long your sprinklers take to fill them to one inch.
Many Western Washington lawns benefit from lime because heavy rainfall tends to make soils acidic, which can weaken grass and favor moss. Not every lawn needs it, though. Test your soil first, either with a lab soil test or a reliable home kit, and apply lime only if the results call for it. Lime works slowly, so apply it in fall or early spring and retest every few years.
Dethatching removes the layer of dead grass, roots, and debris that builds up between the grass blades and the soil. Aerating pulls small plugs of soil out of the ground to relieve compaction, so air, water, and nutrients can reach the roots. Dethatching addresses what’s sitting on top of the soil, and aeration addresses the soil itself. Many lawns benefit from both, especially before overseeding.
Follow your landscaper’s establishment instructions closely for the first several weeks, especially for watering. New sod and seed need consistent moisture until the roots take hold. Keep foot traffic light, and wait until the grass is well rooted before the first mow. Adjust your irrigation schedule as the seasons change. Watch for soil settling near the foundation. The ground around your home should continue to slope away from it so water drains away from the house.
