My favorite late summer annual
"Zinnia peruviana is native in the southern Arizona countryside where I live. Seems to prefer well drained gravelly soils. It pops up and flowers in August and September reliably if there has been adequate monsoon rain. A few years back we seeded a few flower beds with seeds from HCG and have been spreading it all around for 3 years and it has just gone native all around us and showing up in surprising places. One of the three bedrock annual summer flowers for us now along with Arizona poppies and low rattle box. Grows anywhere from a foot high to three feet high."