Four o'clock plants don't like the heat and stay up late

4 o'clock plant in the cool morning
Photo by Dale Bauer

Story and photos by Dale Bauer

“Four o'clock plants (Mirabilis jalapa) are bushy blooming perennials. These tuberous-rooted plants produce slightly pointed oval leaves on branching stems. They get their common name because of the way they bloom. The flowers open in the late afternoon, typically around 4pm or so, and then remain open until the next morning.”  - thespruce.com

Despite what this says, our two plants follow their own schedule, but it is generally based upon avoiding open blossoms during the heat of the day. The first photo shows what our east facing plant looked like at 8 this morning, as the sky was overcast and it was relatively cool.

Same plant at 5 in the afternoon
Photo by Dale Bauer

Here is the same plant at five in the afternoon. Despite the fact that it had been in shade since noon, the heat seems to restrain its exuberance for opening up.

9pm and the plant is opening up
Photo by Dale Bauer

It is, however, opening up now at 9 pm as can be seen in this flash photo.

We started these plants from seeds that we harvested on Vancouver Island 25 years ago. The two plants that have been with us most of that time are planted within a foot or two of the foundation of our basement. 

They both have developed a tuber which is bigger than a large carrot, and I think that may keep them alive when we get the sort of winter weather that kills other plants farther from the house.