Tackling Weeds in a DIY Flower & Garden Bed

My husband and I were really excited about planning a garden. Our backyard is mostly weeds and sand/dirt so we thought we should make something of it and create some above-ground planting boxes. Before we laid the boxes down, we needed to kill all the weeds and grass that were going to be growing underneath the boxes. While this grass would not have come in contact with the actual vegetation in the boxes, we did want to make sure to ever prevent it from growing just in case. You can lay weed blocker down and hope it works or you can use something like Spectracide which can kill any vegetation that it comes in contact with.