The fragrant, heavy-blooming summer flower with the fancy Latin name *Mirabilis jalapa*—better known to most of us as the Four O’Clock flower—hails from the warm regions of South America. These beauties first made their way to Europe in the 16th century and quickly became a garden favorite. Since they’re used to a tropical climate, they aren’t exactly fans of a cold winter, meaning they can’t stay outside when the frost hits.
Overwintering Your Four O’Clocks
This gorgeous summer bloomer gets all its energy for those lush flowers from an underground tuber. You’ll need to dig these up once nighttime temperatures consistently dip below 50°F (10°C). If you store and care for them properly, these tubers can live for several years, so it’s definitely worth the effort! In the fall, you’ll notice the leaves turning yellow and the blooms starting to fade. That’s your signal that the plant is getting ready for its winter nap. At this point, stop fertilizing and cut back on watering. The plant will naturally start to pull nutrients from its stems and leaves back down into the tuber. Here’s how to get them ready for storage:
- Use a garden fork to gently lift the tubers out of the soil.
- Trim back the roots.
- Cut away any rot and dust the “wounds” with charcoal ash to prevent infection.
- Cut the stems down to about 2 inches (5 cm).
- Gently knock off any loose soil.
- Find a dark, cool spot for the winter (ideally between 40°F and 50°F).
- Lay the tubers on a ventilated shelf or
- Store them in a box filled with sand or sawdust.
- Wait until after the last frost in spring to plant them back outside.
Care During the Winter Break
While your tubers are resting, you’ll want to make sure the air doesn’t get too dry. If your storage room is on the dry side, give the tubers a light misting with a spray bottle every two or three weeks. If you have rainwater handy, that’s even better! While you’re at it, give the tubers a little turn every couple of weeks.
In early spring—around late February—check on them to see if they’re starting to sprout. If you see new growth, it’s time to pot them up in some fresh potting soil. Starting in May, you can move your Four O’Clocks to a bright, warm spot during the day. Just remember to bring the pots back inside if the nights are still chilly. Once the danger of frost has passed, you can plant your Four O’Clocks back in the garden bed or keep them in containers on your patio.
