I recently visited the Molino Canyon Vista Overlook along the Catalina Highway to see if there were any seeds on the Sweet Four O'Clocks (Mirabilis longiflora) there. I did find a few of the large, brown seeds remaining on the plants, but most of the seeds had already matured and dropped to the ground.
I didn't find any of the Sweet Four O'Clocks still blooming, even though there has not yet been a frost. The shorter days and cool, autumn nights are prompting these plants and many others to put all of their energy into seed production, so no more new flowers until next year.
Sweet Four O'Clocks make nice, low-care garden flowers, and they can be grown either from seed or from their tuberous roots. They are best grown in locations where they can be appreciated in the evening because their extravagantly long, white, tubular flowers open at sunset and close the following morning.
Even though the flowers are closed during the day, their curling, magenta stamens still can still be seen protruding from the sealed tips of the flowers.