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Growing Four O’Clocks [Can You Use The Seeds?]

Four O’Clock seeds look like tiny grenades, but instead of exploding, they erupt to grow into a new plant. However, besides seeds, one more method exists for growing Four O’Clocks.

Generally, two approaches for growing Four O’Clocks include seeds and tubers. Scarify or soak the seeds overnight in water and start them in warm soil 4-8 weeks before the last frost indoors or early to mid-spring outdoors, or plant the tubers directly in the garden soil during early spring. 

You must continuously nurture the flourishing seedlings after planting the seeds or tubers. Hence, to grasp this process better, stick to the article!

Where Do Four O’Clocks Grow Best?

Four O’Clocks (Mirabilis jalapa) has received its name for its blooming habit, as its flowers only open late in the daytime.

As perennial plants, Four O’Clocks come yearly from seeds or underground tubers that overwinter until early spring.

Generally, Four O’Clocks grow best in warm, humus-rich well-draining garden soil illuminated with 6 hours of full sun daily.
Image represents variegated flowers of Four O'Clocks
Besides well-draining soil and full sun, Four O’Clocks also need a weekly or biweekly feed of balanced fertilizer to flower in summer.

However, you can also use a 1-5 gallon terracotta container for growing Four O’Clock seeds, tubers, or seedlings with the exact growing requirements.

While planting in a container, grow 2-3 plants depending on the planter’s size, but prevent overcrowding.

You can also grow Four O’Clock as border plants in garden beds, ensuring a 1-2 feet distance between the plants.

If you have planned to decorate Four O’Clock in the garden, the corners of raised beds will be an apt place. 

Under the optimum condition, Four O’Clocks can grow 2-3 feet tall and spread 1-2 feet wide.

But, as the plants grow, they need support as their branches are delicate and brittle. 

When to Plant Four O’Clocks?

Four O’Clocks are summer bloomers requiring access to full sun as they cannot tolerate winter frost.

Hence, they grow and beget exquisite flowers in the warm USDA zones from 7-11.

Since Four O’Clocks need warm soil to grow, plant the seeds or tubers during early to mid-spring in your garden soil post-winter.

Additionally, for growing Four O’Clocks, you can start them indoors 4-8 weeks before the last frost date.

This applies to both seeds and tubers, but the latter has certain benefits over seeds. Tubers grow vigorously with good yields.

Methods For Growing Four O’Clocks

Before growing Four O’Clocks, you must collect their seeds or tubers.

The best time to collect Four O’Clock seeds is mid-summer to mid-fall (stretching between mid-August and mid-September).

Only the pollinated Four O’Clock flowers set the seeds, which turn black and rest at the base of the green sepals.

For tubers, dig them out from the ground in the fall when the plants have finished blooming by removing the top vegetation.

Once the seeds and tubers are in your possession, follow these steps to plant them successfully.

1. Growing Four O’Clocks from Seeds

Here’s a step-by-step guide for planting and growing Four O’Clock seeds.

  • Soak the seeds in lukewarm water overnight or gently score their seed coat with sandpaper.
  • Prepare well-aerated, organic soil in raised garden beds during early to mid-spring.
  • You can also use an 8-12 inches wide terracotta pot indoors 4-8 weeks before the last frost.
  • After, dab the seeds about half to a quarter inch deep on the soil.
  • Maintain the soil temperature of around 65-75°F and cover the pots with plastic wrap.
Four Oclock seeds
Four O clock seeds are huge, means there is a greater chance for them to produce prominent plants.
  • Sustain humidity with frequent misting to keep the soil moist.
  • Place the seeds near a sunny window with at least 6 hours of daily direct sunlight.
  • Plant only one seed per container to prevent overcrowding and discourage moisture formation by poking holes in the plastic wrap.
  • After 1-3 weeks, the seeds germinate, and within a few days, they start bearing true sets of leaves.
  • You can now thin out the seedlings and plant them in the garden soil about 1-2 feet apart.

If you missed the season for planting the Four O’Clock seeds, store them in air-tight paper envelopes and wait for the following spring.

Four O’Clock seeds remain viable for 1-2 years when stored in the refrigerator at a temperature of around 4-10°C.

Image represents Four O'Clock seeds placed for germination
You can use seed starter trays for germinating Four O’Clock seeds and later transplanting them into the soil after the seedlings grow new sets of leaves.

2. Growing Four O’Clock from Tubers

The best way to grow Four O’Clock roots, specifically tubers, is to plant them directly in the garden soil post-winter.

After harvesting the tubers, store them in well-aerated cartons, crates, or paper bags in a cool, dry place after removing the top shoots.

Following winter, get ready to plant the tubers in warm garden soil by following these easy steps.

  • Upturn the soil in your garden using a garden fork and mix some organic matter into the soil.
  • Dig up a hole twice in size and an inch longer than the tuber.
  • Space the holes about 1-2 feet apart.
  • Plant the tubers root down into the soil.
  • Fill the remaining space, ensuring the top of the tuber is an inch below the soil.
  • Water the soil thoroughly to prevent dryness, ensuring they receive enough light.

Check this video to learn how to harvest and store Four O’Clock tubers!

Care For Four O’Clocks After Planting

After planting Four O’Clocks, you cannot just cross your hands without effort and expect your plant to thrive.

You must provide adequate care and check whether your plant has fulfilled all its needs.

  • Ensure Four O’Clock seedlings or tubers get full sunlight for at least 6 hours daily.
  • Water the seedlings or tubers every week throughout spring and fall until the onset of winter.
  • Maintain ambient temperatures of around 65-75°F and humidity levels between 40% and 50%.
Image represents the tuber of Four O'Clock
Underground tubers of Four O’Clock plants are a splendid source of propagating materials.
  • Fertilize the plant with a balanced liquid fertilizer 1-2 times a month from spring until early fall.
  • Prune the diseased parts or spent blooms occasionally off the plant to maintain its aesthetics and help it conserve energy.
  • Look for rust, leaf spot diseases, and pests (thrips, mites, aphids, lace bugs, etc.). Ward them off by spraying neem oil.

From Editorial Team

Storing the dry seeds!

You must store only the dry Four O’Clock seeds for a long haul.

To ensure better storage, exclude the use of plastic bags which may capture moisture and rot the seeds.

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