Most who enjoy four o’clock, Miribilis jalapa, do not grow it intentionally. It tends to sneak into gardens from outside, and then bloom too delightfully to be unwanted. It naturalizes, but not aggressively enough to be a weed. New seedlings develop tuberous roots during their first year. They regenerate to produce abundant seed as early as their second year.
Flowers are supposed to open at 4 o’clock. They may open earlier during warm or humid weather. They remain open through the night, and perhaps for part of the morning. Floral color ranges through white, yellow, orange, red, and many tints of pink. Flowers might be striped or spotted with the other colors. Individual plants might bloom with various colors.
Mature four o’clock plants do not get much taller than three feet. They might sprawl twice as broad. Rich light green foliage is quite full, and obscures unexpectedly soft and lanky stems with knobby nodes. Bloom continues through most of summer, but decreases with increased seed development late in summer. All growth above ground succumbs to frost.
Tony Tomeo 
I am sorry that I planted them in a garden bed. They reproduce like crazy and grow a deep tap root that is hard to dig up. On the other hand, they smell delightful.
LikeLiked by 1 person
Wow, not many people actually plant them intentionally. In fact, although I know many people who grow them, I know of only one who actually purchased seed for a particular variety online. I met them in high school, when the moved into the neighborhood as the most common bright pink sort. Two or three years later, a few other colors appeared. My colleague in the Los Angeles region experienced them the same way, as they moved in and got established. Strangely, I can see none in the old neighborhood.
LikeLiked by 1 person
I have a love/hate relationship with these. Fortunately, I have them under an elm tree and along the canyon rim behind our house. They can go to town in those more unkempt areas. They’re difficult to eradicate!
LikeLiked by 1 person
I just mentioned to someone else that they really proliferated in the neighborhood where I lived during high school, and migrated around for several years, but then suddenly died out. My colleague down south made the same observation, although his moved in while he was in grade school. I have not tried to get rid of them here, since they stay beyond landscaped areas, without getting invasive in the wild. In the future, I might dig up the dormant tubers of those with white flowers, and relocate them to my own garden.
LikeLiked by 1 person