What to do when alliums have finished flowering in your garden, according to experts

Wondering what happens to your spent alliums? There are a few ways to make the most of them

 picture of two spent giant alliums
(Image credit: Getty Images)

Watching our favourite flowers finish blooming is always a sad sight, and one that usually leaves us wondering what's next. When it comes to alliums, there are a couple of things you can do.

As one of the best drought-tolerant plants, alliums are a great addition to gardens that get lots of sun or have owners who can't always be outside watering their plants. Sadly, they're not exactly late summer flowers, so the bold purple hues they introduce to your garden don't last forever, and they become spent around late spring.

You might've noticed this change when sorting your garden out, but before you start cutting anything down, here's some useful advice from an expert.

What to do when alliums finish flowering: expert advice

Questioning whether or not you should deadhead alliums in your garden? The answer is a little more complex than just yes or no.

"If you’ve ever wondered what to do with your alliums after they flower, then this is for you, because it’s a really easy process and a lot of people make the mistake of cutting them away straight after it’s flowered," starts Ish, design expert and influencer on Instagram @gardening.with.ish.

picture of spent alliums with seed capsules

(Image credit: Getty Images)

While you might not need your essential gardening tools just yet, you will still need to cut the spent flowers down eventually.

"But the best thing you can do is leave it be. Let it naturally yellow and brown off, and when it has done that, that’s when you cut it at the base, and you can either dig up the bulb or you can leave it until next year. I find they do absolutely fine. This one is in its third year," continues Ish.

Can you plant allium seeds?

If you want to create a more drought-tolerant garden or need more spring-blooming plants, you might be curious if you can plant alliums from seed.

"You may notice that you’ve got all of these lovely little seed heads here, and if you want to grow your own alliums from seed, then it’s actually even easier," explains Ish.

"What you do is you let this dry off completely again and cut the seed head off here on the flower, pop it in a brown paper bag, it’ll dry and crisp up even more, releasing hundreds of little allium seeds, and you can plant those directly in the ground in about a month or so," he adds.

picture of purple alliums growing in garden

(Image credit: Getty Images)

Unfortunately, it might be a while before you get to see the tall purple flowers you're aiming for, as Ish explains.

"But don’t expect to get beautiful flowers next year or even the year after. It does take about two to three years for them to start to establish, but it does happen," finishes Ish.


Alliums are also a fantastic plant if you're looking to start companion planting. The alliums that make good companions are more along the lines of onions and garlic.

Emily Smith
Digital lifestyle writer

Emily joined woman&home as a staff writer after finishing her MA in Magazine Journalism from City University in 2023. After writing various health and news content, she now specialises in lifestyle, covering unique cleaning hacks, gardening how-tos, and everything to help your houseplants thrive.

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