Four O’clock Flowers: Growing from Seeds and Bulbs

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Four o’clock flowers are so named due to their shyness in direct, bright sunlight. When growing four o’clocks, you will notice their tendency to close their blooms during the hottest part of the day and open their flowers after the sun heads for the horizon.

Therefore, the name four o’clocks is pretty accurate… Although, my daughters think they should be called five o’clocks! 🙂 Sometimes they’re a little late to the party, but we know how that goes.

Four o’clock flowers come in a wide variety of colors and range from solid hues to broken colors. The broken colors four o’clock plants are gorgeous, as you never know what each new blossom will look like!

Here in Pennsylvania, we’ve tried growing four o’clocks from seed and bulbs. I enjoy both styles of growing and will likely continue to do so unless I get too busy to dig up the tubers.

In our zone 6b, we have to dig up the root before the winter freezes everything. Growing four o’clock bulbs is easy enough when spring arrives!

I’ll go through the details on growing four o’clocks from seed as well as bulbs and you can decide for yourself what works best for you.

But first, let’s learn a little more about the four o’clock plant!

What are four o’clock flowers?

Four o’clock flowers are lovely ornamental garden flowers that are popular in cottage gardens and beyond. Sometimes known by their scientific name, Mirabilis jalapa, four o’clocks bloom in late afternoon and remain open through the night.

When morning arrives, the bright sun causes these flowers to close up until later in the day once again.

What do four oclock seedlings look like?

Since four o’clock flowers regularly reseed themselves, it pays to figure out what four o’clock seedlings look like. The seedlings of Mirabilis jalapa flowers are bright green with wide cotyledons and pointed, triangular true leaves. The true leaves arrive in pairs pointing alternate directions with each set of new leaves.

What is the four o’clock germination time?

When planting four o’clocks from seed, the germination time may take 7 to 10 days for seedlings to appear. Under the right conditions, four o’clocks may germinate more quickly, particularly indoors under grow lights for a large part of the day.

What is the four o’clock flowers’ height?

Four o’clock mirabilis bushes grow to heights of between 1 to 3 feet tall.

Are four o clock flowers annual or perennial?

You may be wondering, are four o’clock flowers perennials or annuals. The answer is, it depends on where you live. Four o’clocks are tender perennials in the warmer climates, particularly zones 7 through 10. When you live further up north like we do, they are grown as annuals, or you can dig up the bulbs for next year.

Does Mirabilis jalapa reseed itself?

All of this being said, it may seem as though four o’clock plants are perennials because they frequently reseed themselves. The tiny hand grenade seeds fall to the ground and readily germinate in the spring!

What should you do with four o’clock bulbs?

If you live in gardening zones 6b and colder, dig up your four o’clock bulbs if you want to grow them again next year. You can also start new four o’clock bushes from seed if you wish, but the bulbs generally produce a more vigorous plant.

How do you plant four o’clock seeds?

Four o’clock seeds practically grow themselves! Plant Mirabilis jalapa seeds about a half-inch deep in potting soil or a garden of your choice. They may also grow as volunteers, sprouting from seeds dropped toward the end of the previous season.

Growing Four O’clock Flowers from Seed

Follow these easy steps to grow four o’clock flowers from seed.

Indoors:

1. Prepare a seed starting tray or egg carton for planting with potting soil.
2. Gently poke a hole in the center of the soil for each seed cell.
3. Drop a single Mirabilis jalapa seed into the hole and cover it back up.
4. Water with mist from a spray bottle to moisten the soil.
5. Set your seed tray under grow lights or in a sunny window.
6. Check daily for moisture needs and signs of germination.

Once the seeds germinate and grow to be a few inches tall, you should start thinking about transplanting them outside if the temperatures remain above freezing. Be sure to harden off your plants first!

Outside:

You may also plant four o’clock seeds directly in the garden.

1. Choose a location that gets enough sun and has a foot or two of space to support the plant’s bushy growth habit.
   
2. Dig or poke a small hole in the soil for the seed.
   
3. Drop a seed in the hole and cover it back up.
   
4. Place a plant marker to remember what you planted where! (We made adorable seashell plant markers for our garden.)
   
5. Water the seed and any others that you’ve planted.
   
6. Check daily for watering needs and signs of growth!

You may also notice new four o’clocks growing in places you’ve grown them before, since they are so good at reseeding.

Mirabilis jalapa are an excellent choice for a low-maintenance flower garden!

Growing Four O’clock Flowers from Bulbs

Depending on where you live, you may need to dig up your Mirabilis jalapa bulbs if you want to keep them. Here in PA Zone 6b, our temperatures are too cold for the tender bulbs to survive over the winter.

If you do save them, use these tips to grow four o’clock flowers from bulbs in the new season! You should probably wait until the danger of frost has passed.

1. Choose a sunny location that has enough space for a bushy plant to grow and thrive.
   
2. Dig a hole that is twice the size of the rhizome and twice as deep.
   
3. Place the bulb in with the root ends facing downward. (If you can’t tell, place the bulb in sideways and Mother Nature will figure it out!)
   
4. Cover and fill in the hole.
   
5. Water thoroughly and monitor daily to check for moisture needs.
   
6. Enjoy these magnificent flowers in your garden!

The bulb-grown four o’clocks should be a bit more vigorous and larger than the seed-grown ones, but as with anything, your mileage may vary.

It’s so easy to plant four o’clock bulbs! If you’ve saved the dark brown, carrot-like tubers for planting, all you need to do is dig, water, and wait!

Growing Four O’clocks in Container Gardens

A container garden also works for your Mirabilis jalapa flowers.

1. Choose a flower pot that is large enough to accommodate a seed that turns into a bulb or tuber.  
   
2. Dig a hole for the seed or bulb according to its size.
   
3. Plant the four o’clock bulb or seed in the hole and cover it up.
   
4. Water the seed or bulb and check daily for growth.
   
5. Once the plant grows, you can prune it to help shape it for your container. Keep in mind that you don’t want to trim off the flower buds.

If you do grow your four o’clocks in a container, that makes overwintering way easier. You can simply set the entire flower pot inside your garage or basement to survive the winter and grow all over again next year!

Saving and Planting 4 O’clock Tubers

Most gardeners treat 4 o’clock flowers as annuals if the winter climate isn’t suitable for sustained growth. I’ve decided to try planting bulbs from 4 o’clock flowers we liked last year.

After digging up the 4 o’clock tubers and storing them in a bag in our basement, I figured, what have we got to lose?!

You might be thinking, I’ve already got dahlias and cannas to dig up and overwinter – are you really telling me to dig up one more section of plants?!

And, you’re right. Most people don’t dig up and save 4 o’clock bulbs. But if you really like the color combinations of a particular plant it can be worth it.

Can 4 o’clocks be transplanted?

Yes! If you save four o’clock tubers (bulbs) over the winter, you can transplant them in the spring. Simply plant the 4 o’clock bulb as you would any other perennial.

When to Plant Four O’clock Tubers

After the danger of frost has passed is the best time to plant tubers from four o’clock flowers. In our grow zone, PA 6B, we wait until after Mother’s Day to plant tender perennials and delicate annuals.

Benefits of Planting 4 O’clock Bulbs

While it’s not necessary to save and store four o’clock bulbs since they grow so readily from seed, growing these bulbs does have its advantages.

• These plants generally grow bigger and more vigorously.
  
• Four o’clock flowers grow even more prolifically.
  
• Large tubers grow quickly. Eventually, you can even divide four o’clock tubers and share with friends.

Personal Thoughts: Planting 4 O’clock Tubers

Planting four o’clock tubers to grow the plants is a worthwhile task if you can find the time.

I recommend it most if you have grown 4 o’clocks that you love, such as the pink and yellow blend that stole our hearts in our 2021 garden.

If you forever feel busy and rushed in the garden, this might be a task to skip. Here’s why.

Four o’clock flowers grow readily from seed! They germinate pretty quickly and grow big pretty fast.

Also, and probably the biggest reason, is that four o’clocks readily self-seed.

They drop those little black hand grenade shaped seeds like little ticking time bombs!

Even if you don’t save the tubers, and even if you don’t plant 4 o’clock seeds this year, you are still likely to find a few 4 o’clock volunteers popping up around your garden!

The Marvel: Four O’Clock Broken Colors

Some varieties of four o’clocks feature solid tones while others show off stunning displays of stripes and speckles. Just like snowflakes, no two broken colors four o’clock flowers are alike. They’re amazing!

You can buy Mirabilis jalapa seeds for the stunning yellow and pink combination or a pink and white blend. The marbling on each flower is unique and truly breathtaking.

Meanwhile, my heart is set on finding a coral and pink or orange and pink four o’clock broken colors variety to grow. I believe those are called Salmon Sunset or Marvel of Peru, and they’re on my wish list for next year!

Growing Four O’Clocks – Hybrids at Home!

How exciting it was to find a white four o’clock flower had crossed with a pink four o’clock flower and dropped a seed that would later volunteer in our garden!

In late September, a volunteer four o’clock plant opened its first bloom – in broad daylight, mind you – to reveal an impressive and truly beautiful marbled pink and white blossom.

Before this year, we had only grown plain pink and plain white four o’clock plants. We were so amazed to find this unexpected beauty in our garden!

The marbling of the first four o’clock bloom was stunning and I can’t wait to see what the rest look like. It’s so exciting to enjoy something besides the solid colors we’ve had for so long.

Do you grow four o’clocks in your garden? Have you ever happened upon a happy surprise of four o’clocks with broken colors or created your own hybrids?

Let’s chat in the comments below! Hit me with your questions or share your favorite tips and stories about Mirabilis jalapa.

Happy Gardening!

05.25.22 – Updated to change photos to full size and adjust spacing and updated title. Added lots of detail and sections on 4:00 rhizomes / tubers / bulbs.