I am a big fan of the Day Neutral varieties, especially Tri-Star. With them, I've been able to have strawberries from spring through October here in Oregon's Willamette Valley. But anywhere they are grown, keeping them weed-free really makes a difference in yields -- grass especially can really out-compete the strawberry plants for water and nutrients. As a kid in western Kansas, I spent many hours weeding Bermuda Grass and Puncture Vines out of our family strawberry patch! But it was worth it. Strawberries are so good! What sort of gardening stuff are you doing now - has your season started yet, up there in the Seattle area?
Weeds can really effect yields. Landscape fabric works well. I've also used a flame thrower to burns weed seeds on the surface of the soil before planting the strawberries. Once the weeds are burned, the soil cannot be disturbed again or it will bring more weed seeds to the surface causing them to sprout. After burning the surface, add the irrigation line, then the landscape fabric and then plant the strawberries.
Haha -- landscape fabric would have been nice when I was a kid, but I think I was the low-cost option for my dad, lol.