Allium, which is sometimes called “flowering onion,” is a beautiful and unusual flowering bulb that will make any garden more interesting. As the name suggests, allium plants are in the same family as garlic, onions, leeks, and chives. All of these plants have flower heads that look like pom-poms and are round. However, alliums are usually grown only for their flowers. But what should you do with your allium after the flowers are gone? Read on to find out how to take care of alliums after they bloom.
With their unique, spherical flower heads topping slender stems, alliums add fabulous visual interest to gardens. But one key question many gardeners have is – how long is that eye-catching display of color really going to last?
Understanding allium bloom times helps with planning planting and getting the most out of these ornamental bulbs. In this in-depth guide, we’ll demystify how long alliums bloom so you can be fully prepared to enjoy their striking flowers.
Before diving into bloom times, let’s do a quick overview of what makes alliums so special:
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Alliums belong to the same family as edible onions, garlic, chives and leeks. There are over 700 different species.
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They grow from bulbs, multiplying year after year when happy.
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The flowers consist of densely packed, star-shaped florets. The inflorescence is a globe or umbrella-shaped cluster.
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Heights range from only 4 inches up to 4-5 feet tall depending on variety
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Colors include shades of purple, pink, white, yellow and blue.
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Alliums thrive in full sun. Well-drained soil is a must.
Now that you’re familiar with the basics, let’s look at how long those fabulous flowers last.
Allium Bloom Times by Species
There is variability in bloom times, but in general:
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Large, ornamental alliums tend to bloom for 2-3 weeks.
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Smaller species may only bloom for 1-2 weeks.
Here are bloom times for popular species:
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Allium giganteum: Late spring, 2-3 weeks
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Allium ‘Gladiator’: Early summer, 2-3 weeks
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Allium christophii: Early summer, 2-3 weeks
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Allium ‘Millenium’: Early summer, 2-3 weeks
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Allium tuberosum: Early summer, 1-2 weeks
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Allium caeruleum: Spring, 1-2 weeks
Larger alliums give you the most days of enjoyment.
Extending Allium Bloom Times
You can stretch out allium blooms longer through smart practices:
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Plant early, mid and late-blooming varieties for months of flowers.
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Stagger plantings over several weeks to have continuous blooms.
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Provide consistent moisture once buds start swelling for best development.
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Deadhead flowers as they fade to encourage more blooming.
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Plant in groups for greater visual impact.
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Choose sheltered sites protected from wind and rain.
Follow these tips and you can enjoy alliums for up to 6-8 weeks!
Post-Bloom Care for Alliums
Once the show is over, proper care ensures vigorous growth:
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Allow foliage to die back completely before removing. This takes 4-6 weeks usually.
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Stop watering and let bulbs go dormant through summer.
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Cut back dead foliage once it turns yellow or becomes unsightly.
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Divide congested clumps every 3-4 years in fall after foliage dies back.
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Fertilize bulbs with balanced fertilizer when planting and as foliage appears in spring.
Caring for alliums after blooming keeps them thriving year after year.
Matching Alliums to Bloom Seasons
One of the best ways to maximize allium blooms over time is to select varieties from each season:
Spring Bloomers:
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Allium moly
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Allium caeruleum
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Allium karataviense
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Allium nutans
Early Summer Bloomers:
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Allium ‘Millenium’
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Allium ‘Gladiator’
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Allium ‘Globemaster’
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Allium christophii
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Allium tuberosum
Midsummer Bloomers:
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Allium giganteum
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Allium ‘Purple Sensation’
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Allium atropurpureum
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Allium schubertii
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Allium ‘Pinball Wizard’
With strategic choices, you can realistically have alliums blooming for 3-4 months!
Common Questions About Allium Blooms
Here are answers to some other frequent questions about allium flowers:
How long do cut alliums last in a vase?
Cut allium stems will generally last 10-14 days if properly conditioned and cared for.
Why did my allium only bloom for a short time?
Insufficient sunlight, overcrowding, overwatering, or damage from wind/rain can shorten bloom times.
Should allium flowers be deadheaded?
Yes, deadheading faded blooms neatens appearance and encourages more flowering.
Can I cut alliums to enjoy indoors?
Absolutely! Alliums make stunning cut flowers. Just be sure to leave foliage intact in garden.
Should I remove allium foliage after blooming?
Never remove foliage until it completely dies back, so bulbs can recharge for next year.
Caring for Allium Bulbs
Allium plants produce big, round, softball-sized flowers in shades of purple. They do best in sunny, sheltered places where the wind isn’t likely to blow them away. In these conditions, they bloom in early summer and tend to last for about three weeks. Once the flowers have faded, you can deadhead the blooms. But don’t remove the leaves. They need time to fall off naturally so that they can store energy for next year’s growth in the bulbs. It might look like the leaves aren’t arranged very well, so it’s best to put alliums in a bed with flowers that bloom later and hide them.
How to Care for Alliums after Blooming
Allium post bloom care is very easy. Simply keep the plants moderately watered until they fade to yellow and begin to shrivel. You can now cut the plants down to the ground and either leave them alone or split them up. Allium bulbs should be divided every three or four years. To do this, simply dig around the plant with a trowel and lift the bulbs out. There should be a collection of bulbs, which you can separate gently with your hands. Replant a few in the same spot, and plant the others right away in new locations. Caring for allium bulbs that you don’t want to divide is even easier. Just cut back the leaves when they go out of style, and in the fall, put 2 to 3 inches (5-7) of mulch over the soil. 5 cm. ) of mulch. Remove the mulch in the spring to make way for new growth.