My yard is mostly shade. Moss has grown in with the grass in some places. In...
There are several issues to deal with. Depending on the level of shade, it may be necessary that you sow a turf grass cultivar that will tolerate shade, such as creeping red fescue or Chewings fescue (both are 'fine' fescues). Moss prefers a shady area, but will also thrive in acidic soil or compacted soil. And, if you find that the grass has no roots and pulls up easily, it could be the result of grub damage.
The first thing you should do is to have your soil tested. Do this now.
Please refer to HG-110a, the first publication in the list of resources. This is a list of soil testing laboratories in our region.
Since moss prefers acidic soil, it may be that amending the pH of your soil will help in the prevention of moss. Existing moss must still be manually removed before sowing replacement seed. if limestone is recommended on your lawn, you can apply it any time the ground is not frozen.
If the soil is compacted or is low in nutrients and organic matter, you should consider core aerating your soil next summer and applying 1/4 inch of compost before sowing more seed.
If your lawn did suffer grub damage, it is too late now to deal with them. If we have a mild, wet spring and summer next year, you may want to consider applying a grub control product in late June or early July.
In the meantime, please refer to the following publication. This may help you to plan a suitable course of actions to renovate your lawn over the next year.