Roses are fair game for pests and diseases. Here are some of the most common ailments and how to rein them in.
Mildew, rust and black spot are the most common fungal diseases found in roses and also the easiest to control. Dormant spraying in winter can help curb these fungi in the spring. If you do end up with fungi problems, tend to them as soon as possible. The longer you wait, the more difficult they are to restrain. A couple of easy solutions are neem oil or Bayer All-in-One Rose and Flower Care. A hose-end, ready-to-spray applicator makes them easy to apply, requires no mixing and leaves no waste.
If you spot holes on the leaves, look at their undersides for tiny, green caterpillar-like larvae known as sawfly larvae. For a mild infestation, you can pick the leaf off and squish the larvae. If you are feeling outnumbered, you can reach for the Bayer All-in-One Rose and Flower Care, neem oil or any appropriate contact spray. Because rose slugs quickly cause a lot of damage, a contact spray is best.
When aphids feast on the juices of tender growth, it can cause curling, stunting or blackening of new foliage. Aphids excrete a sticky liquid called honeydew that attracts ants. Honeydew can become moldy, smearing black fuzz across the rose leaves and buds. Aphids usually can be washed off with a strong spray of water. You also can purchase ladybugs, which will turn aphids into a fine dining experience. Or you can get rid of aphids with Bayer 3-in-1 Insect, Disease, & Mite Control or Safer Insecticidal Soap.
These may be the smartest of the insects that bug your roses, because they live inside the plant’s tight buds, which makes them difficult to control. Thrips are larvae and they are raspers, causing harm to roses by abrasion. The damage may be most noticeable in light-colored roses. You’ll see the buds become edged in brown or discolored and remain tightly closed or distorted. Sometimes the buds will only partially open. Treat with Bayer 3-in-1 Insect, Disease, & Mite Control or naturally with the Pest Wizard Western Flower Thrips pheromone attractant traps.
Walter Andersen Nursery
3642 Enterprise St., San Diego, CA 92110
12755 Danielson Ct., Poway, CA 92064