My rose trees are getting a white powdery picture.?
Answers: Sounds like powdery mildew, which is technically benign this late within the season. Generally, good growing conditions hang on to the rose well ahead of the fungus.
It can be prevented but not treated...
http://www.ipm.ucdavis.edu/pmg/pestnotes...
It's call powdery mildew. Just make a solution of 1part skim milk to 9 parts marine and spray on your plants making sure to get tops and bottoms of leaves, cane, and trunk.
spray weekly.
"To control minor infestations, pick off artificial plant parts and either compost them surrounded by a hot compost pile or bag them tightly and put them surrounded by the trash... mix 1 part milk beside 9 parts water and spray the stems and tops of leaves near the solution. Reapply after rain. Spraying leaves beside baking soda (1 teaspoon in 1 quart water) raise the pH, creating an inhospitable environment for powdery mildew."
http://www.organicgardening.com/feature/...
"Scientist aren't 100% sure how milk works to control this disease. It seems that milk is a unconscious germicide. In addition, it contains several fluently occurring salts and amino acids that are taken up by the plant. From previous experiments using sodium bicarbonate, potassium phosphate, and other salt, researchers have found that the disease is sensitive to these salt. It is possible then, that milk boosts the plant's immune system to prevent the disease."
http://www.allthatwomenwant.com/milkandm...
Obviously at hand is a critic who does not approve of the organic passageway of controlling powdery mildew. However, thumbs down aside, It really does work.
Good Luck
That is powdery mildew, yes a fungus.
http://plantclinic.cornell.edu/factsheet...
This info may help.
Yes, it is indeed a fungal growth, and it can get hold of bad ample to keep your roses from getting all right light to the fern surfaces. You need to bring a fungicide to spray onto them; it would also be a good opinion to get a systemic fungicide to put into the ground for your rose bushes to transport up into their tissues - sort of IV medication for plants. Check with a nursery implicit you to see what is available.
Good luck!
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