Last year or two I’ve started my garden with zeal and very tight weeding and then once established I have tended to let the weeds grow unimpeded with a late summer / fall cleanup. Why? Because i had more tomatoes and cucumbers than i knew what to do with, never watered my garden once this year, I just did my garden cleanup and produced about a half a cubic yard of mulch from the weeds. And I spotted two large praying mantises during the process. I just wish I had chickens to take advantage of the weeds and the seed heads that developed. Multiple yields.