Question
When is the best time of the year to "power rake" my lawn here in CT?  Last year I purched a Power Rake(Dethacher)at a garage sale at a good price. I figured in the long run it is better then renting junk at $40 per day. Should it be done each year?
Thanks.

Answer
A cool season lawn does not need to be dethached annually. Some very aggressively spreading grasses in the south benefit from one or two annual dethatchings, but cool season lawns are not very aggressive growers. I would limit it to one per year or one every two years. It is a quite destructive process and you need to make sure that it is done just at the begining of an active growing period so that the lawn grasses get maximum recovery period.

De-thatch late spring (mid to late May) or early fall (very late August or early September). Rake any debris off the lawn and then fertilize and water the lawn immediately after.

Good lawn care practices in your area:
- mow the lawn high and mow frequently. Try to not cut the lawn below 2.5-3.5" (meassured after mowing) and mow once or twice per week. recycle clippings to the lawn with a mulching mower if available.
- if you decide to water manually during hot summer months, make sure you water infrequently and deeply rather than shallowly and frequently. Water once per week for 2 hours instead of 15 minutes daily.
- fertilize in late spring, early fall and late fall. Avoid fertilizing too early in spring unless you need to combat crabgrass. Avoid fertilizing during hot summer months.
Apply fertilizer to a dry lawn and water in using plenty of water. If you dethatch in May then fertilize immediately after. If you dethatch in September, then wait until the nights are starting to cool, and then fertilize.
The last fertilizer application of the year (late fall) should be done AFTER the top growth stops, but before the roots go dormant. This may be late october or early november in your area. If you mow weekly in late fall, then wait until you have not had to mow two weeks in a row (because the grass has stopped growing) and then fertilize. This last application of the year is ideal at improving the carbohydrate storage in the roots prior to winter (do not dethatch at this time).