Growing 4 O'clock flowers

Have you ever heard of 4 o'clock flowers? A few years back I was struggling with growing moonflowers and decided to try growing 4 o'clocks instead. They grew perfectly and my love affair with the marbled, multi colored flowers was born!

The 4 O'clock flower, Mirabilis jalapa earned its name because the flowers open around late afternoon each day, and the blooms close and die come morning. Also called Marvel of Peru, these plants were originally cultivated by the Aztecs for medicinal and ornamental uses. 

One of the most unique aspects of this plant, is that different colored flowers can grow on the same plant! Flowers can be solid colored or have a combination of two colors in various patterns.

The plant can also change colors as it matures. You could plant a yellow flowered Marvel of Peru and months later it can start blooming pink.

While it's often assumed the flowers of the 4 O'clock open in response to daylight, they actually open in response to the daily drop in temperature that happens around 4pm each day.

How to grow 4 O'clocks

Soak seeds overnight before planting to speed germination. Marvel of Peru seeds are very hard and they germinate better when the hard outer coating is softened first. If you're direct sowing during a rainy part of spring, you probably won't need to pre soak the seeds.

Planting 4 O'clocks

Choose a sunny location with 4-6 hours of direct sun. 4 O'clocks flower best in full sun, but they can tolerate some shade.

Plant seeds in rich, well draining soil. 4 O'clocks like a neutral soil, though they tolerate slightly acidic soil as well. 

Seedlings should emerge in 7-14 days. Thin plants to 2 feet apart. 4 O'clocks grow very bushy and adequate airflow between plants will help discourage rust. Other than rust, these plants are mostly problem free. The deer seem to like mine, but I have a constant battle to keep deer out of the garden.

You do not need to deadhead 4 O'clocks and they bloom so profusely it would be a daily chore! The flowers tend to just close and stay brightly colored until they drop off though, so most gardeners just leave them be as they're not unattractive.

They are heavy feeders and I like to add about an inch of compost near the base of the plant every few weeks during the growing season. You could fertilize with a 10-10-10 fertilizer about once a month if  you prefer. 

4 O'clocks are mostly drought resistant but may bloom less in dry conditions. I water every 2-3 days to keep the blooms coming.

Saving seeds from 4 O'clocks

Marvel of Peru will self seed unless you collect the seeds first. The seeds start out green but turn black and firm when they're ready. Seeds can easily be plucked off and saved for next year. Allow seeds to dry for several days before storing and store in paper envelopes (not plastic containers) to discourage mold.

4 O'clocks are a tender perennial and will die off at the very first frost of the year. I prefer to grow them from seed each year, but they do develop tubers which can be dug up and saved for the following year if that's your thing. 

If you'd like to save the tubers, dig them up at first frost. Wrap tubers in paper and keep stored in a cool, dark location during winter. Do not wrap in plastic as they could develop mold. 

The 4 O'clock is one of my favorite flowers to grow and it makes a lovely edging plant around patios and you'll enjoy how their lovely fragrance wafts by on the evening breeze.

~L

Related reading: Medicinal uses of Marvel Of Peru.

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