Answer: The rule of thumb is that if an area is more than about forty percent weed then you would kill it out and start over. On the other hand, consistent mowing at the correct height, correcting the pH and optimizing fertility, core aeration and overseeding with an appropriate variety of grass seed can sometimes make a world of difference in a year or so. Either way, this is an excellent time of year to do lawn work and develop a maintenance or improvement plan. To some extent the path to follow will be determined by whether you desire a perfect showplace lawn or simply a green mowed area for the dog and kids to play. I would suggest you begin by running some basic soil tests and consulting with your local county extension. You may also find the following turf grass information helpful. You may need to cut and paste the complete url into your browser ot make it work correctly.
I hope this helps!
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