House Grail is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

How & When To Plant Allium Bulbs: Care Tips, Tricks, & FAQ

allium bulb in gardeners hand

Allium Bulbs, also known as Ornamental Onions, are stunning plants that add a charming look to your garden during bloom season. They are among the most long-lasting flowers and are distinctive due to their globe-shaped blooms with tons of tiny flowers.

They come in variations of colors, sizes, and forms, and many people plant them in their gardens. If you have been considering planting Alliums but were unsure how to do it, we’re here to help.

Check out the rest of the article to learn more about how and when to plant Allium bulbs.

garden flower divider

Is Growing Alliums Difficult?

Although Alliums might seem challenging to grow, it’s quite the opposite. They’re low maintenance so they make a perfect option for beginner gardeners and everyone who doesn’t have a lot of time to take care of their plants.

The whole planting and growing process is pretty straightforward. If you follow all the guidelines below, you will have stunning Alliums in no time.

allium flower
Photo Credit By: Marisa04, Pixabay

How To Choose The Right Allium Variety?

When choosing an Allium variety for your garden, you should consider the flower color, size, and height of the plant. You should look for Alliums that will fit into your garden space and help you create a cohesive, colorful environment.

Flower Color and Size

Allium comes in various colors such as purple, pink, yellow, white, and blue, and different varieties have different-sized heads. Typically, they can range from just 1 inch to over 8 inches in diameter. Some of the largest Allium varieties are the “Globemaster” and “Purple Rain”. Also, not all Allium species have the same amount of flowers, so keep that in mind before planting.

allium flowers
Photo Credit By: Michael Gaida, Pixabay

Plant Height

Alliums can be pretty large and reach over 3 feet, depending on their variety. Smaller varieties can be only 5 inches high, so height is something you should consider before planting Allium bulbs. You can even mix smaller and larger types to achieve a better look in your garden.

garden flower divider

Planting Allium Bulbs

When it comes to planting Alliums, it’s best to plant them in early or mid-fall. Typically, you should plant them about 2 weeks before the ground freezes to allow them to form roots and bloom in late spring or late summer. We suggest planting Alliums between September and November to achieve the best results.

When planting Allium Bulbs, make a hole in the ground that’s about 4 times the bulb’s diameter. You should place small growing Alliums 3 to 4 inches apart, while taller specimens need at least 8 inches between them. Also, follow all the Allium plant requirements we mention below.

planting tulip bulbs
Image Credit: OlgaPonomarenko, Shutterstock

Allium Plant Requirements

  • Light: When it comes to light, Alliums prefer full sun, so you should plant them in a sunny spot where they can easily thrive. If you don’t have a location with much sun coverage, partially sunny areas will also work, but avoid shady areas as the plant won’t grow.
  • Soil: Alliums don’t have special soil requirements, although it must be well-drained. Since they don’t require too much water, they could simply rot if the area is saturated. Also, try to avoid soil with too many nutrients as it could “burn” the plant.
  • Water: Alliums typically prefer dry conditions, so there’s no need for too much watering. Since they are drought-tolerant, it’s enough to allow rain to water them, which will make your gardening job much more manageable. However, if there’s too much drought, which commonly happens between April and May, you can stick with occasional waterings so that they don’t dry out completely.
  • Fertilization: If your soil is poor, you should fertilize the area to promote the growth of your Alliums. Putting compost or a store-bought fertilizer will boost their production and help them grow healthily for many years to come.
Image Credit: jokevanderleij8, pixabay

Additional Care Tips and Tricks for Alliums

There are some other things that you should also know when planting Alliums. These plants require occasional deadheading and dividing.

Care Tips & Tricks
  • Deadheading: People praise Alliums for their bulb heads, but they will require deadheading to ensure that plants won’t reseed in the garden. Of course, that’s not a big deal if you want more Alliums, but they can easily take over the entire available garden space.
  • Dividing: Alliums can clump up over the years and become clogged, so you might need to thin them out. Once they’re done flowering, divide them and replant them on another spot.
allium flowers
Image Credit: Duane Retzlaff, Pixabay

garden flower divider

Final thoughts

By following our simple guide, you can have a stunning Allium garden in no time. All you need is determination and some minimal effort to grow this lovely flower. If you need a reminder on how to grow Alliums, or you’d like some helpful tips on how to grow it, re-read the article and make your garden colorful and vivid!

Featured Image Credit: Max_555, Shutterstock


Related posts

OUR categories

Project ideas

Hand & power tools