One of the problems we had last year was that we went on vacation the first two weeks of June. This was a horrible time to leave. The garden is in full growth stage, which of course means the weeds are in full growth as well. When we came back we could barely tell if anything was alive under the massive onslaught of weeds. Our chard was so puny it barely ever made a comeback.
This year we planted a nice thick bed and have been weeding constantly. Worth it! We have already harvested twice and it just keeps getting better. An onslaught of chard I can handle.