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How to Plant Allium Bulbs in Your Garden in Fall

Kelly Lehman is the owner of Cranbury Fields Flower Farm and shows everyday gardeners how to grow amazing flowers on her YouTube channel.

Kelly Lehman plants allium bulbs at her flower farm every fall, year after year. Here's how she does it (and why!).

Kelly Lehman plants allium bulbs at her flower farm every fall, year after year. Here's how she does it (and why!).

Allium Planting Guide and Tips

Today I want to show you how to plant your allium bulbs. Now, alliums are one of the most beautiful flowers that come up in spring, and they're super unique—they almost look like a Dr. Seuss flower. They've got these giant, poofy heads and they look beautiful in flower arrangements and in people's gardens. And they're super easy to grow!

Here's how to get those bulbs in the ground today.

When to Plant Allium Bulbs

Fall is the best time to put your alliums in the ground. Wait until nighttime temperatures cool off to about 40–50˚F before planting your bulbs.

Allium bulbs must be planted with the root side down and the rounded side up, like so!

Allium bulbs must be planted with the root side down and the rounded side up, like so!

How to Plant Allium Bulbs

  1. Find a sunny spot in your garden.
  2. Dig a hole that's about two to three times as deep as the size of the bulb.
  3. Add some organic compost, especially if you have clay soil, and mix it up like a little cake batter. Then your soil will be good to go. (If your garden has healthy soil with a lot of nutrients, you can also just put your bulbs straight in the ground.)
  4. Plant your alliums root-side down. The rule of thumb with most fall bulbs is that you plant them pointy side up and root side down. But the problem with alliums is that they don't have a point. So what you're going to do is look for the roots—the rounded side (almost like a hard-boiled egg) goes up, the root side goes down.
  5. Make sure that your bulbs are pretty far apart—at least 6 inches or more.
  6. Cover the hole with the soil.
  7. Apply a light layer of mulch over the top (optional).
  8. Water in well if it's not going to rain in the next day or two after you put your bulbs in the ground. Adding your own water ensures that you give these guys the best possible chance of starting out and getting established in the ground before the winter sets in.
  9. Enjoy your beautiful bulbs in spring!
Kelly Lehman shows off a gorgeous flower arrangement featuring alliums.

Kelly Lehman shows off a gorgeous flower arrangement featuring alliums.

Read More From Dengarden

Why Plant Alliums?

In addition to looking pretty in the garden, there are a couple of other reasons that I plant allium bulbs year after year.

  • Most rodents avoid them. One of the reasons that I love planting alliums is because they're part of the onion family, and most rodents stay away from these flowers. So when the rabbits and the deer are going crazy in your spring garden, a lot of times they'll avoid the alliums because they don't like that onion flavor. So that's a great plus.
  • They look terrific in a vase and have a long vase life. These guys will last sometimes like 9 or 10 days in a vase, so they have a terrific vase life if you're a gardener who likes to cut your flowers and make them into flower arrangements.
Lucy Lehman walking through the alliums at Cranbury Fields Flower Farm.

Lucy Lehman walking through the alliums at Cranbury Fields Flower Farm.

What Kind of Allium Should You Grow?

I love the giant Gladiator alliums—they have tremendously large flower heads. But I also love the Purple Sensation allium. It has a little bit of a smaller bulb, and this is the size of allium flower that I use in a lot of the flower arrangements that go out the doors here at Cranbury Fields Flower Farm.

Beyond those two favorites, there are many different varieties of alliums that come in different shades of purple. Some are brighter, some are a little more subtle. And they also come in different-sized heads. I recommend trying out a few varieties and finding the one that works best for you!

Take Size Into Account When Planting

If one variety is much larger than the other, plant accordingly. For example, I know that my Gladiator bulbs are a lot bigger and a lot taller than my Purple Sensation bulbs, so I plant the Gladiators in the background and my Purple Sensations in the front.

More Fall Gardening Inspiration!

© 2021 Kelly Lehman

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