A local tree company delivered free mulch earlier this week, so we have been working on whittling down the huge pile. We got the front yard done and almost finished the backyard today. It's quite a bit of work, but the trade off is it doesn't cost us a dime.
If you can obtain free tree chips(mulch)from your municipality or a tree company, this is a very frugal way of keeping the garden beds moist during hot summers. It also keeps down the weeds, and makes the beds look "finished".
We don't water our garden, so mulching heavily is the only way we can keep a garden without paying large water bills. Our water bills since the drought last year as high enough without having to water the garden. We do water our little vegetable garden, but we use water from our rain barrel.