Plants resume growth each spring from crown buds. Stems branch after plants are 1 to 2 feet tall and plants flower from June to September. Wild four-o clock is named because the flowers open in late afternoon. Pollination is often done by nocturnal insects but self-pollination also occurs. This forces bees and other insects that visit flowers in the morning to visit those that are not yet pollinated.
New plants arise primarily from seed but propagation from root segments is also possible.
Management Moldboard plowing kills nearly all established plants and most wild four-o clock infestations are in fields where this tool has not been used for many years. Thus growing grain crops and using conventional tillage often kills established plants. As with nearly all taprooted perennials, repeated mowing not only prevents seed production but should weaken plants sufficiently so that many die during the winter months. No information on the activity of soil applied herbicides on germinating seeds of wild four-o clock nor of postemergence herbicide activity on established plants of this weed was found. Subsequent row cultivation should be done where possible.