Answer: The first thing to do is run some basic soil tests and check fertility and pH. Then you can fertilize and/or add lime according to the test results. You may also want to topdress with compost to add organic matter to the soil. This would be helpful for both the lawn and garden beds.
Landscape plants should be mulched with organic mulch year round. Apply it about three inches thick in a flat layer over the root area. Do not allow it to touch the stems or trunk of the plants. This will help keep down weeds, reduce watering needs, and help feed the soil slowly as it breaks down over time.
Your yews will need an adjustment period while they become established and rooted. Keep the soil evenly moist like a wrung out sponge (not sopping wet, not dried out) all season until the ground freezes this fall. Watering correctly is the best thing you can do to help them become rooted.
If the lawn is truly weedy, you may need to rework it. The best time of year to do that is surprisingly, late summer. In the meantime, mow it at a height of three inches and mow often enough that you never remove more than one third the grass height. Correct mowing can help a lawn crowd out weeds.
Your county extension should be able to help you with the soil testing and interpreting the results. In the meantime you may find the following lawn care information helpful. You may need to cut and paste the complete url into your browser to make it work correctly.
Meanwhile, enjoy your new home!
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