Question
First of all I reside in Des Moines ,WA. What I need to know is when and how to get my lawn back to par. I,ve tried very hard to do this since we bought the house 7 yrs ago. I need to know how to rid my lawn of moss and to maintain the problem and weeds are a big problem. I also would like to know is there any special type of grasses for my area. I,m from Tenn. and this climate I don't know very well.  

Answer
Moss mainly grow in shady areas. The only way to really combat moss is to allow more sun in by pruning trees or shrubs. Also core areate the ground annually to give the grass best growing conditions.

Fertilize your lawn in late spring, early fall and late fall. do not fertilize during hot summer month or too early in spring.

mow grass high and mow frequently. mow 2.5-3.5" tall after a cutting. recycle grass clippins to the lawn.

If you water manually, water infrequently, but deeply when you do water. it is better to water once per week for 2 hours rather than 15 minutes daily.

Best types of grass in your region for shade and partial shade is FINE FESCUES (hard, chewing, creeping red) or alternatively TALL FESCUE. I recommend buying pre-mixed bags at garden centers which are especially formulated for shade. Avoid high percentages of kentucky bluegrass or perennial ryegrass. Do not plant zoysia.

Moss may continue to be a problem unless the underlying conditions for shade is changed. But to get the best out of a bad situation, you can rake moss in late spring and re-sow any bare spots. also spread grass seeds over the entire lawn at this time and water daily for 2-3 weeks until the new seeds have sprouted and started to grow. Then gradually reduce watering frequency to infrequent, but deep watering.
Overseeding annually in late spring + raking leaves in fall promptly will result in an acceptable lawn.

Remember, do not fertilize during hot summer months.