Sounds like a viral-like disease cause by a phytoplasma called Aster Yellows
- Aster yellows is usually transmitted by leafhoppers as they feed from plant to plant.
- There is no cure for Aster Yellows
- Dig up the plant up roots and all.
- Place in a plastic bag and throw out: do not compost
- Treat all plants for leafhoppers (your county extension service will give you the best recommendation)
- Check all plants in the area for an deformity in the flowers and leaves and throw out
- Aster Yellows can infect many flowers like :aster, Echinacea , zinnia, marigold, Chrysanthemum petunias and snapdragon
- Aster Yellows can also infect vegetables such as: carrots, lettuce, tomatoes and celery.
If you have a question about your plant please submit a ticket with a picture here