Iris Not Blooming? Here’s What to Do

Updated: Jan. 19, 2024

Irises are lovely when they are in flower, but it is frustrating when your iris is not blooming. Find out why and how to solve it.

Why Are My Irises Not Blooming?

iris not bloomingKim Kozlowski/Getty Images
Dig into the cause to find out why your iris is not blooming

“What would cause iris plants not to bloom two years in a row? Three years ago they bloomed,” asks Birds & Blooms reader Rosemary Dzatko of Cuyahoga Falls, Ohio.

Horticultural expert Melinda Myers writers, “It’s always frustrating when our flowers don’t perform as expected.” Here are some likely reasons why your irises are not blooming.

Learn more about Iris flower types and facts.

Irises Are Overcrowded

277876090 1 Gail Deangelo Bnb Bypc 2021Courtesy Gail Deangelo
Divide overcrowded clumps of irises and relocate them.

Overcrowded iris plants often fail to bloom. If this is the case, try dividing the irises this coming summer. Keep in mind that recently divided and transplanted irises may not flower for a year or two after the move.

Learn how to grow walking iris in containers.

Not Enough Sun

Insufficient light caused by increased shade from maturing trees, nearby plantings and new structures can also reduce or prevent iris blooming. Move iris plants to a sunnier location if needed.

Frost Damage on Irises

In addition, a late spring frost can damage the emerging flowers and prevent iris blooming. Tracking the weather often provides clues to problems in the garden.

Excessive Heat

“Every spring when the yellow flag iris (Iris pseudacorus) in my fish pool blooms, the flowers stay wedged in the base of the leaves instead of coming up on stems. What causes this?” asks reader Irene Holzman of Pensecola, Florida.

Melinda says, “Environmental stress can cause the stunting of flower stalks. Make sure the rhizomes have plenty of room to grow. Excessive heat and sun in hot climates like yours can also stress these plants.”

Backyard Tip: Yellow flag iris is an invasive perennial and is considered a noxious weed in many states. Look for native blue flag iris instead.

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