how long it takes is up to where you put the cover. when do you need it to produce? If you want to catch fish now, then put it at a depth and area where you are fishing now. if you have a tournament when the water temp is going to be in the mid 50's, then put it in the 8-12 foot range. If you want fish to spawn in it, then put it in 4-6 foot. keep this in mind, if you have a bare bank or bay with almost nothing in it, the fish will be thrilled to have something for cover. If there are already 500 standing trees in it, you will be sharing your fish with all the other trees. let's do a little math, divide 5000 fish by 500 trees and then divide 200 fish by 4 trees. I would rather fish an area with just a couple brush piles than a big cove full of cover. If you put something in the water, where the fish are NOW, you will have fish on it very quickly. If you put it where they WILL be, it will be good later. I hope this helps.