Insect & Disease

Most bugs are good; a few pests provide food for the “good guys.” However, sometimes the “bad guys” get out of hand and you might need to take action. Less-toxic insecticides, such as horticultural oils, insecticidal soaps and pyrethrins kill only those insects they contact, but are quite effective at reducing pest populations. Systemic insecticides such as Bayer Advanced Garden Rose & Flower Insect Killer are absorbed into the plant tissue and kill sucking insects such as aphids for a 3-week period. These products also contain a contact poison that kills chewing insects on contact. Since insecticides kill good as well as bad insects, they should be used only when absolutely necessary.

Pesticides are products containing chemicals or other agents designed to kill or disable pests. Herbicides destroy vegetation, miticides control mites, insecticides kill insects, and fungicides combat fungi. Some products combine a fungicide and an insecticide.

Messenger is a non-toxic product that activates a plant’s natural defenses, which helps it fight off disease and stay healthy. Messenger is applied as a spray every 2-3 weeks throughout the growing season.

Fungicides are preventative, not curative. A regular spray schedule is recommended for fungus protection. An all-purpose fungicide will prevent mildew, blackspot, and rust. Some are more effective with specific diseases, so Rosarians often rotate products in their spray program. Less toxic fungicide options include Green Light (neem oil), Safers Garden Fungicide (sulfur) and Concern ( copper soap fungicide). The next line of defense, if the less toxic options are not working, includes Spectraside Immunox Fungicide (myclobutanial), Garden Tech Daconil Fungicide (chlorothalonil), and Bayer Advanced Disease Control (tebuconazole).

There are a number of alternative pesticides, as well as beneficial insects, on the market that can be used to limit or control insects and diseases. Often they are hard to find in local nurseries. Contact a local consulting Rosarian for more information.

Early morning spraying allows the foliage time to dry. Be sure to spray the underside of the foliage, where most insects live and spores germinate. After a spray material is mixed with water, use it within a couple of hours; it loses effectiveness if kept overnight or longer. Spraying should begin right after pruning time; fungi and insects have been dormant and protected during winter, and by pruning time are becoming active and vulnerable to pesticides.

Choose a sprayer that produces a fine mist. For a few plants, a pistol-grip sprayer will work. For more plants, choose a plastic pump sprayer; these range from ½ to 2 gallons in capacity.

Bayer Advanced Garden All In One Rose & Flower Care combines a fertilizer, a fungicide and an insecticide in one product to be applied as a soil drench every six weeks. This eliminates the need for spraying. However, the product becomes expensive if you grow more than a few plants.

The pesticide products on the market have undergone stringent testing and have been approved by the EPA. They are safe if you use common sense and follow directions. Read and follow all labeling directions. It is illegal to use a pesticide in a manner not in accordance with the label instructions.