Starting Seeds for My Shade Loving Containers

I always like to start a few plants (well, probably over 100) to add to my shade loving containers. My second seed order arrived today from Stokes Seeds - and the growing instructions on the package of Alternanthera 'Royal Tapestry' says that they need to be sown 11-12 weeks before they are ready for sale in 4" pots. (Stokes do a large commercial business.) I'm using my frost free date of about May 12th to count back from so, I must sow them this week. The germination temperature is between 64 to 75 degrees F or 18-24 degrees C - about the average temperature of my basement. I noticed that these seeds require light for germination. So I'll put them in either a zippered plastic bag or put the pot in a tray covered with a clear plastic hood.

This is a trailer that can be used in either sun or shade. The colour will be lighter in the shade, but I'm hoping will still be vibrant enough to show off the other annuals and tropicals I hope to mix it with in my containers.