Answer: This might begin to help cover the bare spots, but if not, your best time of year for lawn work is actually late summer to early fall. In the meantime you should run some basic soil tests and see how much fertilizer you need to use and also if you need to apply lime to adjust the soil pH. This will help your existing grass grow better and also be helpful for any work you do later on.
Your local Penn State county extension should be able to help you with the soil testing and interpreting the results. They should also have suggestions as to the best type of grass variety to use based on the conditions in your yard, and also have recommendations for general lawn care maintenance and renovation.
For example, here are the recommendations for renovating a lawn: (You may need to cut and paste the complete url into your browser to make it work correctly.)
Additional lawn care information is available at their web site.
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