There are no seasonal restrictions for planting and growing moss with spores.Keep soil moist after sprinkling the spores on damp soil. It should take approx. 4-6 weeks to see rich growth. Usually purchased in 1/2oz packs. The link below is a good inexpensive source. http://store.auctiva.com/mybonsaibuddy or http://stores.ebay.com/My-Bonsai-Buddy