Getting Ready to Plant

We're new to greenhouse planting and just found out from Eliot Coleman's book that you can use the planting dates for two zones south. A quick calculation in the spreadsheet says that we can start planting several vegetables - Celery, spinach, peas, beets, kale, cabbage and salad greens. So now, we're scrambling to get the seeds started in the soil blockers which will then be set out in the greenhouse. This is also the date to plant onions (seed) for spring planting in the garden. We're hoping to sell at Farmer's Markets or here at our farm stand this summer. How many to plant - that is the question. I'll start with a couple hundred onions and will plant more next week. This is so exciting - I can't wait to see everything green and growing.