Plant diseases

Why is My Echinacea Turning Green?

First the disease affects echinacea’s cone, causing green growth to appear. Photo:

Yes, there are a few plants with green flowers: green roses, green zinnias, green glads, green echinaceas, etc. These plants are hybrids developed for their unusual color. But if a plant you choose for flowers of another color suddenly starts producing green flowers, the chances are pretty good it is suffering from a disease: aster yellows.

Aster yellows is a very common in the wild, found especially in goldenrods, asters and other wildflowers, and is caused by the aster yellow phytoplasma (AYP), a bizarre entity closely related to bacteria, but behaving like a virus. Notably, once a plant is infected, no treatment can cure it. 

Leafhoppers transport aster yellows from one plant to another. Photo:

Aster yellows are transmitted by leafhoppers: by piercing plant tissues, they inject the phytoplasma which then extends gradually throughout the plant, affecting its growth and gradually weakening it.

Over time, the entire flower turns green and often begins to produce satellite flowers. Photo:

The first symptom in many plants is the greening of the flowers. This is called phyllody, the abnormal development of floral parts into leafy structures. In the case of echinaceas, a kind of green growth starts to form on the cone in the flower’s center. Over time, the cone produces small satellite flowers that are completely green. Weird … and really not too wonderful!

The only treatment for aster yellows is to destroy the plant. If left alive, the disease will gradually spread to neighboring plants, including echinaceas, asters, carrots, cosmos, strawberries, daisies, marigolds, zinnias. More than 300 other plants in 84 different plant families are known to be infected by this disease.

This is a case where a quick strike solves a ton of future problems: yank the infected plant out at the first sign of symptoms and you can prevent the disease from spreading to your other garden plants.

Article originally published on September 27, 2014. 

Garden writer and blogger, author of 65 gardening books, lecturer and communicator, the Laidback Gardener, Larry Hodgson, passed away in October 2022. Known for his great generosity, his thoroughness and his sense of humor, he reached several generations of amateur and professional gardeners over his 40-year career. Thanks to his son, Mathieu Hodgson, and a team of contributors, will continue its mission of demystifying gardening and making it more accessible to all.

8 comments on “Why is My Echinacea Turning Green?

  1. Thanks for this as I have never seen this before, and I have grown echinaceas many years in several different states. This really had be confused. Will the soil be okay for re-planting new plants?

  2. Thanks for this – I had this exact problem this spring and the flowers looked exactly like that. I wasn’t sure whether to pull them until I found this.

  3. How do you know that the first picture is not a coneflower with Eriophyid mites? How can you tell?

    • Largely because I trust the source of the photo. The main difference is that you can cure a plant of mites (i.e. cutting it down to zero in the fall) and it will grow back “normal” the next season. It won’t with aster yellows.

  4. I had not heard of this in many years. I remember others talking about it in the late 1980s, probably because it had just been a problem for field grown cut flowers on the Central Coast.

  5. Thank you for this learning moment because I’d never heard of this.

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