My wife and I continue to plant swamp milkweed near our ponds and wetlands. It has formed nice colonies in some places and does have an attractive flower. I have observed more monarch caterpillars on the swamp milkweed plants compared with the other perennial milkweed species on our place. Our non-hardy tropical milkweed also seems to be very attractive to monarchs and makes a good flower-garden plant. We continue to spread swamp milkweed around. I also found that clay-adapted butterfly weed does very well on our soil (also a milkweed). We probably have about 10,000 milkweed plants on our place (mostly common milkweed), but we need them to be planted all along the migration route, so please help from south to north! https://www.prairienursery.com/butterflyweed-for-clay-asclepias-tuberosa-var-clay.html