When the clock strikes 4 pm, these beauties are just getting ready for their show. That’s right – four o’clocks are nocturnal flowers that bloom through the evening and begin to fade in the morning light.
For these ladies of the night, it’s all about the temperature. When the day cools down, they heat up the garden with an abundance of blooms.
Four o’clocks (Mirabilis jalapa) are annuals for most of us but can be grown as perennials in Zones 7b-11b. Often grown from seeds, this tuber plant is a charming addition to any garden.
Whether you direct sow seeds into the garden soil or begin plants six weeks earlier inside, choose a sunny spot for their home. Four o’clocks like full sun but will tolerate some afternoon shade. If you plant from seed, let them soak in water overnight to speed the growing process.
When happy, the plants will grow 1-4 feet tall and 1-3 feet wide—pinching the stems when just about five inches tall will encourage bushier plants.
The flowers are 2-inch trumpet-shaped blooms in various colors, including reds, pinks, yellow and white. Here’s a surprise – the blooms may change colors mid-season.
Like daylilies, the four o’clock flower only blooms once then fades and falls off the plant leaving behind seeds that you can collect, or they will drop and self-seed. Don’t be sad. This plant blooms with reckless abandonment and will produce color from June until autumn frost.
To keep the plant blooming all season, a monthly dose of fertilizer is helpful. Deadheading the spent blooms is not necessary, but gathering the seeds is a good idea.
Collect the seeds and let them dry for about a week, then place them in an envelope or glass container until next year. But why wait? Share them with others who want to add this nostalgic bloomer to their garden.
Another way to propagate four o’clocks is to dig up the tuber and dry them over the winter, exactly like dahlias. Dig the tuber – yes four o’clocks are tubers – shake off any loose soil, and lay between newspapers to dry. Be sure to keep them in a dry spot that won’t freeze until time to plant in the spring.
I learned this lesson the hard way. Last fall, I carefully dug my dahlia bulbs and laid them out to dry. I made sure there was good air circulation because I know this is important to keep them healthy. I must admit, I was pleased and excited about the upcoming spring.
Fast forward to March, and my tubers were mush. I was so disappointed. My mistake – I stored them in a place where the temps dropped below freezing. Yes, the was a very cold snap that probably sealed their fate, but I will not make that mistake again this year.
Four o’clocks will draw pollinators, including those that feed at night. Keep this plant’s nocturnal blooming schedule in mind when planting. Think of adding them near your favorite evening relaxation spot. It would be silly to waste their show on an area you do not see after 4 pm.
Please note four o’clocks are toxic to animals and humans if ingested.
Four o’clocks may be an old fashion plant, but I would argue that they have been around for years because of their beauty and magical powers to create beauty in the evening garden.