This past summer was my first attempt at growing Four O'clocks. Not certain if they were deer and groundhog resistant, I opted to try them in a flower pot. I soaked about 10 seeds overnight in a small bowl of water and planted them the next day in a large flower pot. Success!
White ones ....
and a red ones bloomed! The flowers were fleeting ... lasting only one day, but they were lovely. I didn't realize that they take nearly 90 days to bloom. I regret that I had started them so late in the season, mid-June. Flowering didn't begin until late September. I will definitely begin earlier next year. The growing season in the Poconos is relatively short. Since hard frosts are common from mid-October on, and measurable snow is possible before the end of the month, I usually begin my Fall clean-up at the beginning of October.
Early this afternoon I had decided to pull the last of the spent annuals from the flower pots on my back deck. When I came to my pot of Four O'clocks, I was surprised by the resistance I encountered when I tugged at the tall, withered stalks. Applying quite a bit of effort, I finally was able to pull the plants out. I couldn't help but smile. Well, I'll be ... tubers! I did vaguely remember reading somewhere about Four O'clocks forming tubers. So, I cleaned them off and put them on the deck rail to dry out a bit. When they are dry enough in a few days, I'll dust them with sand and put them in paper bags, store them in a cool, dry place, and plant them in the Spring.
Four O'clocks are also known as Marvel Of Peru. They come in trumpet-shaped blooms of yellow, red, white, pink, and striped and bi-color. The generally bloom from early summer until frost.
In our zone 5, after all danger of frost has passed (mid-May), sow pre-soaked seeds directly in the garden 1/2 inch deep in rich, but well drained soil in full sun or part shade. Sow seeds 4-6 inches apart. Thin to one foot apart when the seedlings are a few inches tall. Watering needs are moderate since they are fairly drought tolerate. Feed every 6 weeks during the growing season with water soluble fertilizer.
To grow from tubers, after all danger of frost has passed (mid-May), plant tubers in the garden with the long tap root end facing down so that the whole tuber lies at least one inch below the soil line. General care is the same as growing from seeds.
To grow tubers in pots, after all danger of frost (mid-May), plant tubers in a large flower pot, about 3 plants to a pot. Growing directions are the same as above, but container grown Four O'clocks will require more watering.
In our zone 5 climate Four O'clocks generally will not self seed or winter over. Pull and store tubers in the Fall and replant in the following Spring.