Ok, here's what my report from the Diagnostic Lab said verbatim:
We found two diseases on the sample you provided, blackspot and Botrytis blight.
Blackspot, caused by the fungus Diplocarpon rosae, was found on the foliage. This disease will cause the leaves to drop prematurely and heavy leaf shed will reduce flower production and vigor. If severe drought conditions further stress blackspot-damaged roses, the plant may die. To control blackspot on roses, start with regular fungicide applications. For effective season-long disease control, begin fungicide applications shortly after spring bud break and continue at a 7 to 14-day interval until the first hard frost. Also, collect and destroy all leaves on the ground. Prune diseased or weakened canes at bud swell and replace the soil mulch in late winter or early spring.
Botrytis blight, caused by the fungus Botrytis cinerea, affects buds, flowers and peduncles. The disease usually starts in the flower bud, decreases the longevity of the flower, and may move down to the stems. Cankers may form as a result of Botrytis infection and are similar in appearance to those produced by other stem canker and dieback fungi. Sanitation practices such as the removal of spent blossoms as well as the collection of fallen leaves and petals from around the base of the plant should reduce the risk of Botrytis blight. Immediately prune out blighted blooms, canes, and buds. Fungicides used to control blackspot are also effective against Botrytis blight.
For more information about rose diseases see ANR-505 at http://www.aces.edu/pubs/docs/A/ANR-0505/. This publication will also give you a list of fungicides labeled to control blackspot and Botrytis blight.
So I thought about it, and my decision is to treat my bushes since they hold sentimental value. And it gives me a reason to continue this blog. lol!
Here's a really cool fact...after my training session at MG school, I came home and told my husband that my roses had some sort of fungi. See, told you I paid attention. :)
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