In Tumwater, Olympia, and Tacoma, fall isn't the end of the yard season. It's the setup for the next one. Cool nights and steady rain make October and early November the best time to fix what summer left behind.
Start with the leaves. A thick layer of maple and alder leaves left on the lawn through November will smother the grass underneath and leave dead patches by March. Rake or mulch-mow them every week or two while they're falling, and clear them out of beds where they'll hold slugs and moisture against your plants.
Keep mowing as long as the grass is growing, but stop lowering the blade. Leaving the lawn a little taller going into winter helps it handle the wet months and crowd out moss. Your last mow is usually in early to mid November.
Winterize your irrigation before the first hard freeze. Shut off the water to the system, drain or blow out the lines, and turn the controller to rain mode or off. A cracked backflow or split line in spring is a much bigger repair than a fall shut-down.
Finally, clean the gutters after most of the leaves have dropped. Overflowing gutters in a South Sound winter soak the ground along your foundation, rot fascia boards, and feed moss on the lower edge of the roof.