Even after many years of starting seeds indoors, I make the same mistake year after year. I inevitably run out of room. Partly because I sow way too many plants (can’t help it), but truly, I have not planned my spacing appropriately
Thanks Donna re posts. The 1 shelf (both sides) came with the greenhouse package, but you could use many utility shelving packages from Costco or home improvement centers. Some of the shelving is the little GH sold with the plastic zip up cover.