Yardsmart: How to grow chemical-free roses

Do the leaves of your roses turn whitish and puckered? Perhaps your beautiful buds or even the flowers succumb to alien powder? These are symptoms of one of the most vexing diseases of roses, which is in fact a fungus. Known as powdery mildew, it has bedeviled rose growers since the earliest times. Fighting it and other afflictions of the rose is expensive, laborious and more often than not, toxic.

While there are different types of rose diseases, most thrive on moist leaves that are shaded in the cool morning hours. These long hours create a perfect environment for fungus to form. Double that in a humid climate. For roses in such locations, you're fighting a losing battle. Of course there are other causes of disease, but this problem exposure is the most common.

Many years ago I planted roses on the sunny west side of my house where they'd appreciate the long, hot afternoons. For the geographically challenged, the west side faces the setting sun. To my surprise every plant was plagued by mildew. When you find all the plants in a group experience such a problem, it tells you that location is the problem. If the cause was simply a weak rose variety susceptible to mildew, that plant would be stricken while the others remain free or nearly free of the disease.

Because I'm a fundamentally lazy gardener, I refused to succumb to spraying fungicide be it chemical or organic in origin. Because I'm conscious of the environment, I shy away from systemic products as well. I had no choice but to move the roses that year to the east side of my house while they were dormant in winter. That would ensure that morning dew would quickly evaporate in the hot sun. From that day forward I rarely saw any signs of mildew in those very same plants.

It has always been my philosophy that if a plant is too much trouble it's not worth growing. Therefore I have always advised my California gardeners to plant their roses in a similar exposure or abandon the idea altogether. Nobody wants to become a slave to a spray regime.

Roses grow best when they're in a fully open exposure, and this is why all the famous rose gardens are laid out in large spaces untouched by shadows cast by trees and buildings. In addition, this guarantees free air circulation that helps to keep foliage and flowers dry. Adequate separation between individual plants is equally important because crowded bushes or those left inadequately pruned become a haven for fungal diseases. Visit any of the public rose gardens around the country and around the world to see these principles in action.

The trump card is that some varieties are simply more vulnerable to diseases than others, but the label won't tell you that. The key to chemical-free roses is to consult the experts.