White Flower Farm: The premier American mail-order source for plants, bulbs, and gardening supplies.
Offers Free Catalog (Eye Candy Galore), Plants
boo note: Ok, not a cheap source for plants, but don't let the prices scare you. You get what you pay for and White Flower Farm offers nice sized plants and some unusual varieties. Their customer service contacted me when I accidentally tossed a plant in the cart that wasn't for my zone. Overzealous clicking on my part, but they could have taken advantage of that. I'm very pleased with these guys.