Milkweed are quite tolerant of sun and drought. Will the runoff from your gutter be washing over the seedlings once they are planted? I don't think they could survive that, especially if you get a heavy rain. These seedlings would prefer as much sun as possible, even all day. I would plant the incarnata plants at least 20 inches apart, and the tuberosa 15-18 apart. You could fill in the spaces in between with nectar-rich annuals such as zinnias, pentas, lantana, asters, etc. As your milkweeds mature and spread, you can expand your butterfly garden to continue to include more and more varieties of plants, if you want. You may not get any blossoms this year, so no seeds, either. I would encourage you to plant more seeds next year, just like you did this year. Once the Monarchs find your garden, you want to be sure you have plenty of food for any caterpillars you might be hosting. Also, females prefer to deposit eggs on young, tender leaves. I found most of my eggs on the very smallest new seedlings, rather than on the established plants that were blooming.

I hope this helps. The butterflies don't care what your garden looks like, as long as you have what they need growing there. Make sure you can see it from a window or that you can sit somewhere comfortably to watch and enjoy any visitors. Good luck.

Martha

Along c your Milkweed and annuals, I would also include perennials such as Joe-Pye Weed, Liatris, Asters and Goldenrod. You can also incorporate reseeding annuals such as Cosmos and Tithonia. Monarchs need all these for the migration South.
Other butterfly host plants include:
Virginia Snakeroot, Fennel, Everlasting, Pussytoes, Passion Vine, False Nettles and Spicebush.
You can plant Wild Cherry trees and Tulip Poplars as well for RSPs and Tiger Swallowtails.