The mixture should be light, seedling mixes are a good choice. My current favorite is a 50-50 mix of Just Right Xtra and Just Right Lite. Add enough water to make a doughlike consistancy, and let set for 1-2 hours. The mix should be able to be pressed into balls and somewhat hold their shape. […]
I’ve had good luck with Just Right Xtra. It is made in New York, and I’ve visited the facility. It has one of the most horrific mixing chambers I’ve seen.