Hope you don't mind if I chime in very late on this thread. My first concern if I were starting an online nursery business - after learning all the rules and regulations, as Lin said above - would be to learn how to package your plants so that they arrive intact and healthy to where they're going.
How to do this? Well, I'd start by ordering some plants from well established nurseries, and take pictures of the packaging when they arrive so you know how they did it. You can buy things that you can then propagate for your own nursery, of course. There's good packaging and bad, as well. I've had badly packaged plants arrive in very rough shape from Logee's. Very surprising considering how much they charge! Great packaging, and also a good deal on shipping from Vintage Green nursery in Hawaii. And excellent packaging of transplant-size babies in custom made plastic holders from Burpee's.
Also, make notes as to when to ship and when to wait, according to the weather. Be sure to publish this on your website, "can't ship when it's too cold or too hot" applies of course to both where you're shipping from, and where the plant is going to. I've had plants arrive, cooked to mush because they were shipped when the weather was too hot and they rode around in the back of a hot UPS truck all day. I'd assume you are in Florida, since you're on the Florida Gardening forum?
Take a look at Tropiflora's website for their guidelines as to when they ship, and when they wait. Good luck with your new venture!
