Lay down a thick layer of CARDBOARD in your raised garden beds to kill the grass. It is perfectly safe to use and will fully decompose, but not before killing any grass below it. They’ll also provide compost and food for worms.
Instead of using commercial fertilizers and plant food, why not use some scraps from your kitchen that would otherwise end up in the trash or compost bin to amend and improve your garden soil naturally? Inexpensive and easy, these are my favorite ways to get my garden ready for spring planting. Eggshells, banana peels, Epsom salts, coffee grounds. Find out more at http://www.fresheggsdaily.com/2016/06/7-ways-to-improve-your-garden-soil.html