Ever wondered if the charming, colorful 4 o’clock flowers return year after year? If you’re a gardener looking for low-maintenance beauty in your backyard, you’ve likely stumbled across the vibrant blooms of 4 o’clocks. These unique flowers not only offer a pop of color in the late afternoon but also bring up the age-old question: Are 4 o’clock flowers perennial or annual?
Let’s dig into the nature of these fascinating blooms, their growing habits, and how you can make the most of them in your garden.
What Are 4 O’Clock Flowers?
4 o’clock flowers, also known by their scientific name Mirabilis jalapa, are beloved for their:
- Fragrant, trumpet-shaped blossoms
- Ability to bloom in the late afternoon or evening
- Variety of colors, often on a single plant
Native to tropical regions of South America, these flowers earned their nickname from their peculiar habit of opening around 4 PM — a delightful surprise for evening garden strollers.
Are 4 O’Clock Flowers Perennial or Annual?
The Short Answer: It Depends on Your Climate
In the world of gardening, whether a plant is perennial (returns each year) or annual (completes its life cycle in one growing season) often depends on hardiness zones and climate.
- In USDA Zones 7–11: Yes, 4 o’clock flowers are perennial. They can survive mild winters and regrow from the same roots year after year.
- In colder climates (Zones 6 and below): They behave more like annuals unless you take special steps to preserve them.
The Secret: Tuberous Roots
One of the reasons 4 o’clocks can come back each year is due to their thick, tuberous roots. These underground storage systems help the plant survive dormancy, especially in warm climates. If you’re in a colder zone, don’t worry — we’ll talk about how to save them later.
Growing Conditions for 4 O’Clock Flowers
To enjoy healthy, long-lasting blooms, make sure you provide the right conditions:
☀️ Sunlight
- Prefer full sun but tolerate partial shade.
- More sun = more blooms.
🌱 Soil
- Thrive in well-draining soil.
- Tolerate poor soils, but flourish in moderately fertile ground.
💧 Watering
- Once established, 4 o’clocks are drought-tolerant.
- Water moderately; avoid overwatering, which can rot the tubers.
How to Make 4 O’Clock Flowers Perennial in Cold Climates
If you’re outside their hardiness zone, you can still enjoy 4 o’clocks year after year with a little extra effort.
🪴 Option 1: Dig and Store the Tubers
- After the first frost, cut back the foliage.
- Carefully dig up the tuberous roots.
- Let them dry for a few days.
- Store in a cool, dry place (like a basement or garage) in peat moss or sawdust.
- Replant in spring when the ground warms up.
🌱 Option 2: Let Them Self-Seed
4 o’clocks produce plenty of black, pea-sized seeds. In some areas, they self-sow generously, coming back the next year like perennials.
- Collect seeds at the end of the season.
- Store in a cool, dry place.
- Plant in spring after the last frost.
Benefits of Growing 4 O’Clock Flowers
These flowers aren’t just pretty — they’re also practical! Here’s why gardeners love them:
- Long blooming period from mid-summer to fall
- Low maintenance once established
- Natural pest repellent (especially against Japanese beetles)
- Pollinator-friendly, attracting moths and hummingbirds
Common Questions About 4 O’Clocks
🌼 Do 4 O’Clock Flowers Spread?
Yes, they can! Through both seeds and tubers, 4 o’clocks may naturalize in your garden. If you want to keep them contained, consider planting them in containers or bordered beds.
🐶 Are 4 O’Clocks Toxic to Pets?
Yes, all parts of the plant — especially the seeds and roots — are toxic to dogs, cats, and even humans if ingested. Keep them out of reach of curious pets and children.
🧪 Why Do They Open in the Afternoon?
Their opening pattern is a response to temperature and light levels. As the sun dips and temperatures cool, the flowers open — a trait that evolved to attract evening pollinators like moths.
Final Thoughts: Should You Plant 4 O’Clock Flowers?
Absolutely! Whether they grow as perennials in warmer zones or annuals with overwintering options in colder ones, 4 o’clock flowers are a rewarding addition to any garden.
Their vibrant colors, enchanting scent, and evening blooms make them a standout choice for gardeners of all skill levels.