I've got a bunch of samples into the Diagnostics Lab at the University of Delaware in the hopes of having a positive confirmation about the status of the cone flowers that are in my garden, and if they have
Aster Yellows (which visually, I'm certain they do).
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| 2011 Cone Flower Third Known Year Symptomatic |
I first looked at my most recent photos from 2011 - above.
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| 2010 Cone Flower Second Known Year Symptomatic. |
Then 2010 when I remembered seeing odd growths on some of the cones - above.
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| 2009 Cone Flowers |
Then by chance I looked back at some 2009 photos - and sure enough - it was there too…
Back then I didn't really know that plants got "diseases".
Never really put much thought into it.
I though it was some kind of genetic variation.
Pretty cool looking actually - although something felt "off" about it...
Here are a bunch of other photos from 2010:
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| 2010 Purchased Cone Flower Varieties for Front Bed. |
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| 2010 Cone Flower Second Known Year Symptomatic. |
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| 2010 September Cone Flowers with petal curl & odd cone. |
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| View of 2010 Main Side Hill Garden Deer is in Upper Bed. |
And some 2011 photos before I took most all of the Cone Flowers out in June 2011:
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| A thing of beauty up close - 2010 new plants in front bed. |
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| May 2011 Main Side Hill Garden. 2009 divided cone flowers growing. |
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| May 2011 Front Side Hill Garden. 2010 transplanted from Main Side Hill Garden |
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| Main Side Hill Lower Tier Cone Flowers |
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| Main Side Hill Lower Tier Cone Flower Symptomatic Second Year Growth. |
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| Main Side Hill Lower Tier Cone Flowers Second Known Year. |
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| Main Side Hill Garden upper Tier Second or Third Year (sample submitted). |
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| Detail of "not normal" cone flower from upper tier. |
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| Abnormal growth of the upper tier smaller variety cone flower. |
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| Front Cone Flower Bed. Back Right = Front Side Hill Garden. |
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| Detail of cone flower from Front Side Hill Garden. |
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| Second year growth Front Side Hill Garden (transplants from Main Side Hill Garden). |
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| Removal of Cone flowers from Front Side Hill Garden. |
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| Heavy downpour in July. Opposite view of Front Cone Flower Bed. |
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| October view of Front Cone Flower Bed. |
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| 2010 purchased plants showing symptoms at end of second year in bed. |
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| 2010 Purchased plants showing irregular growth and leaf curl. |
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| Final view of Cone Flower Front Bed from where I took a lot of samples to be confirmed. |
I can visually see the symptoms of Aster yellows.
I've heard that it might not be Aster Yellows but rather damage from GoldFinches or possibly from a mite.
I wanted to see if the UD lab could diagnose this for me.
And if a positive result comes back for Aster Yellows - then what.
I guess all of the cone flowers will be dug up.
But what about the suppliers selling them - and the suppliers supplying them?
I've been to both places and have seen the symptoms on their stock.
And then what?
Do I find a list of the 300 species of plants it affects and pull them out too?
But what about my neighbors that have plants that might get this?
What about the insect that transmits it?
Did it die? Did it migrate? Is it overwintering?
Realistically what are the measures to be taken about this?
And to think - all those potentially great seed sources for birds overwintering - now gone.
That really stinks.
Looks like I'm going to have to stock up on extra bird seed for this winter.
UPDATE: UD says that the symptoms that they see indicate Aster Yellows or possibly a genetic mutation. Their lab cannot test for Aster Yellows.
I went online and googled to find some extra help.
I know I have to pull them all out.
Should I then pull out any other plant that might be infected - what plants are on the list of over 300 species?
Integrated Pest Management Strategies
1. Remove diseased plants. Once a plant is infected with aster yellows, it is a lost cause since the disease is incurable. Early diagnosis and prompt removal of infected plants may help reduce the spread of the disease. Although the disease itself is not fatal to the plant, its presence makes it impossible for a plant to fulfill its intended role in the garden.
2. Plant less susceptible plant species. Controlling aster yellows is difficult. As long as infected leafhoppers are around, they can infect plants. A practical way to avoid having problems with this disease is to grow plants that are not as susceptible to aster yellows. Verbena, salvia, nicotiana, geranium, cockscomb, and impatiens are among the least susceptible plants.
3. Control insects. Vegetable growers may protect susceptible crops by using the mesh fabrics that keep leafhoppers and other insects away from the plants. Some growers put strips of aluminum foil between rows because bright reflections of sunlight confuse the leafhoppers.
4. Control weeds. Remove weeds in your lawn, garden, and surrounding areas, including plantain and dandelion that may harbor the disease.
Q.I'm rebuilding a perennial garden that was infested with aster yellows. Do you have any advice?
A. Aster yellows disease causes distorted growth and sometimes death of susceptible plants. The phytoplasm (bacterium-like disease organism) infests more than 300 species of plants with members of the aster family such as coneflowers, Rudbeckias being some of the most susceptible. The disease lives in the infested plants and is spread by aster leafhoppers from sick to healthy plants.
Remove all infested plants and weeds from the garden. Controlling leafhoppers will help reduce the spread. I have not found an up-to-date comprehensive list of resistant plants, so I would suggest you check out each one of the plants you plan to add. If they are not listed as susceptible or resistant, you might want to start slowly and limit the number of aster family members you include.
And finally - Kansas State University Cooperative Extension (1993):
Some other questions I've got that I would like to find out answers to is:
1. If a plant that becomes infected with Aster Yellows, that was already forming seeds - are those seeds infected too? It is know that infected plants may not produce viable seeds, but should seeds from these infected plants be grown for the following year or disposed of.
2. What is the best way to deal with the soil that the plants were in? Is there something environmentally friendly (friendly to other plants, insects, animals, etc) that will kill off anything that remains in the soil? Or is this pointless because the insect does not pass on the disease to future generations. What about treating the soil in general for other fungus and disease? Maybe there is a product that will help "clean" the soil a bit since we have hot & humid as well as cool & humid seasons all year here in Delaware.
Would love some feedback...
