Ayimera,
That Buttonbush gets really big. I just read that they get: 5 to 12 feet high and 4-8ft wide! So, you might want to hold off on putting anything else in there for now. I am in Zone 7b, and I would suggest that you plant a couple of butterfly bushes if you don't have them already. Just run up to Lowes or Home Depot and buy the little inexpensive ones. They grow really fast. I really like Pink Delight. They normally also have Black Knight which is a nice contrast to the Pink Delight. Remember that they can get up to 10 feet tall and 5-6 feet wide, so leave some room between them. Some Lantana would also be great somewhere else in the yard.~~Angie

The buttonbush is actually on the other side of the yard (not in the picture), so it should have enough room. So those ones there are just the flowers.

I'd suggest planting some annual nectar plants like zinnias or annual salvias now. They will provide color and attract butterflies sooner while your perennials mature and fill in. Both BES and the milkweed will spread, and the milkweed will drop seeds that will sprout. So, that spot could eventually be filled easily with what you have planted now.

Martha

Plant some Fennel or Dill somewhere in your yard to attract Black Swallowtails. Also, some Passionvine on your fence. Aristolochia (Pipevine) is a vine that attracts Pipevine Swallowtails. Coneflowers and Mexican Sunflowers are great nectar plants.