Allium Plant – How To Grow Alliums In Your Flower Garden

Allium Plant – How To Grow Alliums In Your Flower Garden

By: Becca Badgett, Co-author of How to Grow an EMERGENCY Garden

The allium plant is related to the simple garden onion, but don’t let this deter you from planting it for its beautiful blooms. In fact, minimal allium care and a show of large, early-to-late season blooms are just a couple of the reasons to include the ornamental allium plant in the garden.

Learn how to grow alliums, which are also related to chives and garlic, for their large and showy flower heads and as a repellant for many insects and wildlife you may wish to keep out of the garden. More than 400 species exist and offer a wide range of bloom sizes and bloom times.

Flowers of the allium plant rise above the foliage, and you can grow alliums in the colors of white, pink, purple, yellow, and blue. Flowers of the allium plant have round heads too, which range from a few to several inches (7.5 to 15 cm.) around. The cultivar ‘Star of Persia’ (A. christophii) is one of the shortest growing alliums and has a multi-colored flower head 6 to 8 inches (15 to 20.5 cm.) across. A. unifolium has a single leaf from which numerous flower heads rise and bloom in pink, lavender, and white.

How to Plant Allium Bulb

Include several allium bulbs in your autumn bulb planting for height and color in the spring garden. Scatter them among bulbs of lilies, crocus, and some of your other favorite spring blooming bulbs for tall, sporadic color throughout your beds next year. When the soil has warmed, plant seeds of the candytuft flower and other short perennial flowers to cover foliage of the growing alliums as they wither away when the show is done.

Plant the allium bulb three times its height deep in well-draining soil in a sunny location. Growing alliums in the flower bed may deter aphids, which often like to suck on tender new growth of other spring blooms. Growing alliums in the garden deters rodents, the peach borer, and even the destructive Japanese beetle.

Allium care is simple if planted in the right soil and sunlight. The allium plant needs only infrequent watering, weeding, and fertilization. These needs may be taken care of by rainfall and by adding organic mulch after planting. An organic, pre-emergence weed block or mulch may cut down on weeding.

Learning how to plant allium bulb can be beneficial to many of your other growing specimens. Learning how to grow alliums is a useful garden trick that you will practice for years to come.

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You might know the allium family from the chives in your herb garden: little fluffy purple balls much beloved by bees and butterflies. But ornamental alliums are anything but little. These gigantic globes on tall stems are all about bringing big drama to your garden. If you grow bulbs with children, be sure to include some alliums, as children love the fact that once in bloom these flowers will often tower over them.


Bloom in late spring and summer





When your DutchGrown alliums arrive and you can’t plant them immediately, it’s important to store them correctly: unpack them right away and put them in a dry place with plenty of air circulation, where the temperature is between 40 and 70 degrees Fahrenheit.

Garden & Container Planting

Like all flower bulbs, alliums need a cold period to develop their roots and get ready for spring. So once you feel fall’s first chill in the air, it’s time to get planting.

Flower bulbs are tough cookies that are easy to grow, but one thing they hate is getting their feet wet: a bulb that is ‘bathing’ in water will rot in no time. So avoid soggy soil at all cost – this means places where you can still see puddles 5-6 hours after a rainstorm. Another thing you can do is to upgrade potentially soggy soil by adding organic material such as peat, bark or manure. When it comes to planting bulbs in containers, the mantra is exactly the same: drainage-drainage-drainage. Get a pot or box with at least some drainage holes at the bottom.

Alliums need plenty of light to grow, so any place with less than full sun is out.

Alliums will need to be planted deep enough that they won’t be affected by temperature variations above ground, either too warm or too cold. Unfortunately containers can’t protect bulbs as well as mother earth can, so when you live in hardiness zones 3-7 it might be better to let your containers spend the winter indoors, in a cool, dark, well-aired spot that won’t get warmer than 60 degrees Fahrenheit, like an unheated basement or garage.

The standard method for calculating the ideal depth is to dig a hole three times as deep as the bulb is high, and place the bulb at the bottom with its pointy end up. Since alliums grow less well when they have to fight for nutrients with their fellow bulbs, it’s best to plant them 6-8” apart.

To help the bulbs settle and grow roots quickly, it’s important to water them well after planting, but after that you won’t have to water them again. Now all you have to do is wait patiently for winter to do its magic underground, and spring to surprise you with the rewards of your work.

During blooming season, you generally don’t have to water your alliums, but you can water them when there hasn’t been any rain for 3-5 days.

After alliums have finished blooming, don’t cut the foliage straight away: through photosynthesis the leaves will create nutrients that the bulb will be needing for its next growing season. After a few weeks the foliage will automatically yellow and die back, and then you can remove it. Now the bulb will be going dormant, and won’t need any watering until next spring.

How to plant alliums in your garden:

  1. Wait until the soil is 60 degrees Fahrenheit or colder. In the North this will be in September or October, in the South in October or November.
  2. Pick a spot in your garden that has well-draining soil and gets full sun.
  3. Plant the allium bulbs about 4-8” deep and 6-8” apart, placing them in the ground with their pointy ends up.
  4. Water well once and wait for spring
  5. After the alliums have bloomed don’t cut off the foliage. Leave it until it’s completely withered and yellow, then remove.

How to plant alliums in containers:

  1. Wait until it’s cold outside, with a soil temperature of 60 degrees Fahrenheit or lower. In the North this will be in September or October, in the South in October or November.
  2. Pick a spot in your garden that gets full sun.
  3. Find a well-draining container and fill it with loose soil, making sure water won’t gather and stay at the bottom.
  4. Plant the allium bulbs about 4-8” deep and 6-8” apart, placing them in the soil with their pointy ends up. Since containers often have limited space, you can also experiment with placing the bulbs closer together, but make sure they never touch.
  5. Water well once and wait for spring, or, when you live in hardiness zone 3-7, water well and bring the containers indoors, letting them spend the winter in a cool spot like an unheated garage or basement.
  6. After the alliums have bloomed don’t cut off the foliage. Leave it until it’s completely withered and yellow, then remove.

Special effects

If you like things neat and tidy or want to maximize the wow-factor alliums can bring to your garden or container, you can opt for the super regimented approach. Grow your alliums in very neat rows of about 10 bulbs planted quite closely together (you might want to add some fertilizer to the soil to make sure they still get all the nutrients they need). An even greater effect can be achieved by growing a row of 10 taller alliums such as Purple Sensation behind a row of 10 slightly smaller ones like Azureum .

Alliums: A Field Guide

Ornamental alliums—not to be confused with the edible chives, garlic, and onions which also belong to the Allium genus—are versatile perennial flowers with long-lasting blooms.

With purple puffball flowers shaped like dandelions gone to seed, alliums had whimsy and visual punctuation to a flower border. After the blooms fade, leave allium’s seed heads in place to feed the birds.

Some of our contributor Kendra Wilson’s favorite varieties to grow (and to use as cut flowers in floral arrangements) are “sublimely round” Allium hollandicum ‘Purple Sensation’ and smaller, egg-shaped Allium spherocephalon. Not to mention her favorite pink varieties: Allium nigrum ‘Pink Pearl’ or the big ones, such as mega Allium schubertii.


Easy-to-grow Alliums provide one of the most effective ways to ensure continuing color and beauty in your garden after spring-flowering bulbs have faded. While you wait for the cheery blooms of summer flowers it's easy to enjoy the outstanding features of Alliums:

• Exceptionally easy to grow with little concern for soil conditions.
• Intriguing, unique character of blooms that are a delight to behold.
• Great ornamental value after flowering because the flower heads continue to provide an interesting display even after the colors have faded.
• Great in dried arrangements.
• Ability to naturalize exceptionally well by multiplying year after year for increased beauty.
• Distasteful flavor for animals, so they won't eat any part of them.
• Attractive to hummingbirds!

Alliums come in all shapes and sizes and are lots of fun to grow. They fit into almost any garden setting and provide a much-needed bridge of color between spring and summer flowers. Sometimes called "ornamental onions", Alliums do best in full sun with well drained, fertile soil and good moisture. Plant them in September or October about 8-10" deep. Allium really look best in the company of other summer bloomers. Sweet alyssum, rock cress, bachelor's buttons, coreopsis, sweet William, foxglove, baby's breath, daylily, iris red hot poker, coralberry, barberry, Japanese Maple, Deutzia rosea, weigela, and Geranium pretense are just some of the companion plants that look fantastic with Alliums.

All there is to know about allium

Allium is a perennial that grows quite easily which will produce very beautiful purple blue flowers that can be up to 8 to 12 inches (20 to 30 cm) across.

Native to Europe and Asia, this ornamental onion belongs to the same genus as the following species: edible garlic, onion, shallot, chives and belongs to the same family as leek.

The different Allium varieties all boast superb flowers bunched up in balls and the size and color of this ball depends on the variety.

In flower beds or along edges, and also along a wall or simply plunked in the middle of the yard, the ornamental impact of this plant is guaranteed!

  • Allium giganteum, thanks to its tall bearing, is perfect to line the back of a flower bed.

It is also used in flower bouquets, because the foliage and the flowers both can be used to make appealing bouquets.

Watch the video: How to Plant Allium Globemaster: SpringSummer Garden Guide