Water Snowball (Gymnocoronis spilanthoides variegatus) seems like a magnet attracting Monarch Butterflies & remains blooming throughout end of migration in midwest i.e. October. Water Snowball can be grown in clay soil within pot set inside another larger pot filled with water - as it is not necessary to have actual pond. Blooms are little (size of a large pea) white, & strongly, sweetly scented & seem to almost exclusively attract Monarchs (9 observed at once on one plant). Water Snowball is not native in midwest & does not do well overwintering indoors. However, Water Snowball worth replacing every year after you observe: Extremely Happy Monarchs discovering these little, lucious nectar blossoms while on their long and difficult journey south!!!