My mother has moved house and has a fairly large garden ( grass area
probably at least tennis court size). I have made her 3 wood compost
bins 1 metre square.

Question? I get 5-6 containers full of clippings from the mower, is
this too much to put in compost bin as balance of compost material from
kitchen & garden is much less. I am hoping to utilise the clippings
without having to take them to council waste site, if possible