lots of time, people not let seeds run against anything as they growing up to help them push the shell off, in coco thats huge advantage since I can completely bury it and keep adding more until it gets pushed off, hydro I would think is slightly more tricky I think in hydro I'd be waiting until 3/4 inch long tap root... I probably could stuck my 1/4 inch tap root in yesterday, but today it's doubled in size so that should help me out some..I do feel better knowing it doubled in one day, I can say they them two very viable, doubling everyday. same with duurty's them break ground yesterday and little over 3/8" to 1/2" sticking out of coco now, so not bad at all...