The method Lay the mat flat on a table or floor, pop the corners together so the edges stand up, then put your tools and plants on it. Work as messily as you like – mix soil, repot, propagate or water; it all stays inside the lip. When you’re done, unpop one corner, tip the excess soil back into the bag, wipe the mat, fold it, and put it away. No hoovering up half a pot of soil afterwards.