A few years ago if you had asked in a garden department or nursery for an organic fungicide, you would have received some rather strange looks.

The words organic and fungicide indicated opposite points of view. Not anymore.

Last year two organic fungicides, Exel LG and Serenade were introduced. Neither was widely distributed so many gardeners didn't know about them. This year, Exel LG still is rather hard to find, but Serenade is finding its way to garden shelves all over the Pacific Northwest, including locally.

Exel LG's active ingredients are mono- and di-potassium salts of phosphorous acid and it is considered a systemic fungicide. A systemic fungicide is one that actually enters the plant through the leaves and thus is better able to protect the plant. It effectively controls various plant diseases including black spot, root rot, bud fall, downy mildew, late blight and canker blight and phytophthora in ornamentals, bedding plants, conifers and turf. It may be used on apples, avocados, citrus, cucumbers, grapes, lettuce, potatoes, stone fruits, roses and trees. The cost for a quart is about $25.

Exel LG may be applied as a foliar spray, soil drench, basal bark application or bare root dip. Dosage depends on the disease and plants being targeted. On roses, the application rate is one tablespoon per gallon of spray.

Although classified by the state as an organic fungicide, safety precautions still should be used when spraying with Exel LG. The label rates its toxic level as “caution,” which is the least harmful classification. I've used Exel LG for two years now and have been very satisfied with it. If used faithfully from early spring to fall it protects roses from black spot and downy mildew. However, since it is a systemic fungicide it should not be the only fungicide used in the garden. Fungi have a tendency to mutate or change when only systemic fungicides are used, thus making them more resistant to the fungicides.

Serenade, which can be found as both a concentrate and ready-to-use spray, is more of a protectant type of fungicide. That means it coats the plant's leaf surfaces and thus protects the plant from a fungus invasion. It can be washed off the plant with water, rain or a heavy, misting fog.

Serenade also controls bacterial spot, powdery mildew, rust, gray mold, leaf blight, scab, black spot and downy mildew on vegetables, fruit and nut trees and roses. Its active ingredient is Bacillus subtilis, a bacteria.

A lot of research is being conducted in university labs using different forms of bacteria as fungicides. Serenade is the first to be classified by the Organic Materials Review Institute as effective, and I'm sure it's just the first of what will result from cutting-edge research.

The application rate for Serenade is two to four tablespoons per gallon, making it rather more expensive than Exel LG to use. A 32-ounce bottle of concentrate costs about $20. Its precautionary rating is also “caution” but I still would use the same precautions when spraying with Serenade rather than with regular fungicides.

Also, unlike Exel LG, Serenade can be used only as a foliar spray.

However, if the gardener wishes to take a more organic approach to gardening but still wants disease-free roses, either one or both of these fungicides should go a long way toward keeping roses healthy.

(Corinne Clifton lives near Bandon and grows more than 200 kinds of roses.)