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Re: 1st Attempt to grow roses in Houston (or anywhere)

William Groth recently wrote

>I would like to keep my plants including the roses organic and need
>to find 
>something organic to eliminate or prevent the pathogens which will likely
>attack 
>these plants in the hot, wet climate in Houston.

Dr. Ken Horst, a professor of plant pathology at Cornell, developed a 
fungicidal spray that proved highly effective against blackspot and 
powdery mildew when tested on a number of hybrid teas. The "recipe," 
published in the September 1992 issue of The American Rose (the magazine 
of the American Rose Society) is as follows:

3 teaspoons sodium bicarbonate
2.5 tablespoons Safer Sunspray ultrafine horticultural spray oil
1 gallon water

The formula is to be used weekly.

I've used it myself and found it to be effective when applied regularly. 
It's important too not to use more baking soda than specified above; 
higher amounts can cause leaf burn. I think it's better to apply the 
spray early in the morning so that leaves are dry by the time the sun 
gets hot. Just a hunch.

Spraying is a hassle, but at least when you use the baking soda spray, 
there's no need to wear rubber gloves, long pants, goggles, long sleeves, 
etc. to protect oneself from chemical exposure as when one uses 
commercial fungicides.

Good luck.



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Mary C. Weaver
Freelance writer and editor:
magazines, books, newsletters, corporate communications
mcweaver@usit.net
http://www.geocities.com/Athens/1104/
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