I bought 20 hydrangea seeds
How can get them started in small pots in the house and how many in each little starter pot?
Certified GKH Gardening Expert
I would only place one per pot to save you trouble later on with trying to separate them. This article will help: https://www.gardeningknowhow.com/ornamental/shrubs/hydrangea/growing-hydrangeas-from-seed.htm