... Mona, thanks for the helpful tip on putting fine bark in the bottom of the big pots. I noticed in a photo you posted of your rearing houses the big tubs of milkweed sitting about. The milkweed looked so healthy. I have one very big green plastic tub in the garage that I use to drag around and pick up piles of leaves. I'm going to drill holes in the bottom of it and put it to better use growing milkweed. I find, all of a sudden, I'm planning my plantings around the milkweed and nectar plants for the butterflies and hummingbirds! It's actually more fun to grow FOR something than to just plant for the sake of growing something.
...wyvern, my thanks for your helpful information on growing the common milkweed. Good advice; what is invasive in one garden wouldn't necessarily be so in another garden. I may get brave and try one in ground, just to see how it performs. My yard is small and my planting space is limited so I like to try and make best use of the little bit I have.
Now, my next big project is getting the perennial milkweed seed to germinate. I've had the seed in the fridge for almost a month, now, in damp coffee filters in zip lock bags. I took two seeds of two different varieties out yesterday and planted them in a cell pack, just to see if either would germinate. I left the remaining seeds as is in the fridge. I've read several lengths of time suggested for cold stratification, none at less than a month
but couldn't resist the urge to try.