Roundup Promax penetrates weed leaf surfaces faster, giving you confidence. When spraying Roundup on a weed, it is absorbed by the plant, where it then prevents the plant from making its own food and gathering nutrients to sustain itself. Roundup is then transported throughout the plant to kill the entire weed, roots included. And thus, dead weeds can't grow back. Once in the soil, Roundup breaks down over time into natural substances and will not move in the ground to affect nearby, untreated plants. It is a post-emergent, systemic product with no soil residual activity. Roundup Pro Concentrate gives a broad spectrum control of many annual weeds, perennial weeds, woody brush and trees.