How To Prevent Rose Pests And Diseases
Prevention and good cultural care can reduce the number of challenges your roses will present each season.
Follow these tips for healthy roses:
* Select disease-resistant varieties
* Follow good pruning practices
* Do not over fertilize
* Encourage beneficial insects
* Avoid working around roses when their leaves are wet
* Promptly remove any leaves that are infected
How To Prevent Black Spot
Black Spot Disease
Black Spot is a fungal disease that can run rampant on wet foliage. Black spots can develop on the leaves, which then turn yellow and eventually drop off. This stresses the rose and weakens it.
To prevent black spot, start a spray program as soon as the leaves emerge in spring using fungicides labeled for black spot. I like to use a systemic such as Bayer All-In-One Rose Care available at most garden and home improvement centers. Adjust your watering so that you do not wet the leaves of your plant – water the base of the plant, preferably early in the day so that the plant dries out quickly.
Dealing with Powdery Mildew
Powdery Mildew is a fungus that needs hot, humid days and cool nights to flourish. To prevent this disease you can spray your rosebushes with a homemade “tonic” made from mixing 1 tablespoon of baking soda with a gallon of water. Add a few drops of mild liquid soap. Keep shaking the bottle as you spray the foliage. Reapply every 5 days or as necessary. Do not spray during the heat of the day or the leaves will burn.
Combating Aphids, Mites and Thrips
Aphids are tiny insects found in large groups on the tender rose shoots. Spray aphids with shots of water to knock them off the rose. Inspect regularly to check for their return.
Mites are very small insects that live on the underside of the leaves. They breed quickly in warm weather. Spray them with water to knock them off, checking frequently to see if they have returned. If the infection is very bad, use and insecticidal soap spray such as the Safer brand.
Thrips are very small insects that feed on buds and flowers. They can be thwarted using an insecticidal soap also.
Eliminating Japanese Beetles
Japanese Beetle
These shiny fluorescent green beetles appear in July in the Midwest. Their larvae live in well-watered lawns and garden beds for over 10 months of the year. (Eggs are laid beneath the plants that the beetles feed on) The best way to remove them is to pick them off by hand and drop into a bucket or coffee can of soapy water. The soap prevents them from flying away.
If you are squeamish of bugs, just wear rubber gloves so you aren’t directly touching them. You can also treat your lawn and garden soil with parasitic nematodes, milky spore or chemicals made for grub control.
