I use them when I'm out of root plugs. Just beware that they hold a TON of water when they expand and you will not have good results unless you squeeze the excess water out of them after soaking them. I soak mine in warm water until they expand, then I gently squeeze the water out of them and let them sit in a closed container for at least a few hours before I use them so the water in them will even back out and they puff back up a bit. Make sure you squeeze them from top to bottom, otherwise the peat will come out, and you will make a mess. Once I see a sprout, I fill solo cups with my soil, plop them in, and then put a thin layr of soil over them to prevent them from drying out too quickly.