My Golden Gate Gardener column in today's S.F. Chronicle (www.sfgate.com) answers a question about four o'clocks. The seed for the plants in question was brought from China, where it turns out these bright flowers are immensely popular.
The species is Mirabilis jalapa, a plant that is not known in the wild, but is believed to be native to Mexico. It is found in all of the former Aztec sites as well as places where the Spanish built colonial towns and is still a popular plant in Mexico and elsewhere in Central America.They are considered an "old garden flower" in this country.
It seems that the plant is also very popular in China, a fact I didn't know when I featured it in Wildly Successful Plants: Northern California. An exchange student brought some seeds here (which is probably illegal), and said they were common in her village. I am told they are grown as an annual where not hardy, and as a perennial where they are, just as they are here. (Now I am so curious to find out which other flowers are popular there.)
So the plant started in Mexico, went to Spain, and thence throughout Europe, then back to America, where Thomas Jefferson grew some in his garden, then accross America to California, while also probably coming up with those who came to California from Mexico. (The plants we photographed for the book came from Mexico as seeds in the pocket of a lady who was moving to Menlo Park.) And also, across Europe and into Asia? (Are they grown in Russia or India?) Or did they arrive with Europeans in China? Or? And then, back to California from China.
There are more variations in the plants than I thought as well. The plants from China reach 4 to 6 feet tall, which I am told is typical of the species, while varieties from seed catalogs are shorter, maybe 2 feet tall. There are fragrant ones, such as the ones Jefferson grew beneath his window so the wind could waft the scent indoors on summer evenings, and ones with no scent. There are ones that truly open at 4 o'clock, and stay open at night for the pollinating night-flying moths, and ones that open in the morning and close at night.
The most popular varieties are usually the ones with "broken colors," that is, ones that have flowers streaked and splashed with 2 colors, along with solid color flowers of both colors, on the same plant. These can be any combination of white, yellow, or magenta.
Some would consider them too common to grow, but they can be glorious, big shrubby plants, covered with bright flowers for a couple of months, favored by hummingbirds, perhaps scented. They can make a nice summer hedge.
The caution is that they can reseed, but they may not. If they do, and the seedling is in the crack of pavement or brickwork, take it out, since the big tuberous root will be hard to remove or kill in this situation.