In my old home the walls are made of plaster how do i repair them?

You can cheat and use the stuff they use for drywall, especially since it's going to be behind the molding, but if it's large then I'd use real plaster. There should be wood lathing running horizontally along the wall--hopefully that's in good shape & will assume so from here. Clear any loose plaster away, then use the mesh tape to cover the whole and trowel on a light layer of patching plaster (can be purchased ready mixed at Lowes/Home Depot, most hardware stores); let dry for at least 24 hours. Repeat until plaster is even with existing walls-usually 2 coats, sand smooth and paint. This Old House.com has an excellent video on plaster repair.

Well I am no professional at this, but they used to make a little tub of ready-made plaster that you could get at the hardware store. You may be able to repair is a little spots without it being too noticeable. Somebody else may have better advice but that's my two cents

Hi The 21986874,

I also have old plaster walls and over the years have repaired a lot of places using regular Spackle or dry wall putty. It does sink in a bit when it dries so you need 2 coats, then sand it smooth and feather the edges. Also prime before painting. It's always worked well for me. Wishing you the best.