spindly camellias and rhododendrons
 

I planted some camellias (japonicas) and rhododendrons about nine years ago,
and have neglected them for the most part. Some have done OK, but some have
grown very spindly with few leaves. I was thinking of replacing them, but I
hate to just throw the old ones away. If I transplanted them and cut them
way back, would they regrow and regrow healthily if I actually gave them
water and fertilizer, etc? I live on a gravel road means that between rains
there's a lot of dust. When I wipe away the dust, underneath the leaves are
speckled brown.