Roses: Diseases & Pests
Gardeners aren’t the only ones that love roses. Rose bushes can be the favorite of insects and certain plant diseases too. But with proper maintenance and care, the rose is still one of the easiest and most rewarding flowers to grow.
There are many insects that love roses. Aphids, white flies, mealy bugs, Japanese beetles, rose borers, to name a few. Don’t be dismayed by this though as they are generally easy to get rid of once you have discovered them.
Many of these rose pests can be controlled with insecticidal soap or even removed by hand or by a jet of water. There are a number of effective products, many of them environmentally friendly, available for rose pests. Some cover a variety of insects while others are specific to a particular type. So although many insects would love to make a meal of your roses, you will find that a weekly inspection and quick treatment of your rose bush will prevent any widespread infestation.
Depending on the area in which you live, you may encounter different rose diseases, but there are three main afflictions that are universal to roses everywhere.
- Black Spot – This looks just like the name. Black spots appear on leaves and stems of the rose bush. The leaves eventually fall off and the whole plant can become denuded. The most effective treatment is an application of dormant oil and lime sulfur before the new growth appears in the spring. All the infected leaves and branches need to be removed along with any laying on the ground in order to prevent re-infection.
- Powdery Mildew – A powdery light colored fuzz appears on the rose leaves and even new buds. Left untreated, it will spread throughout the entire bush eventually killing the foliage. It can be treated with a commercial spray or you can try making your own by combining three teaspoons of baking soda and two tablespoons of vegetable oil with one gallon of water. Spray the mixture on in the mornings on the top and underside of all the leaves. This won’t remove the damage to infected leaves, but will prevent the spread to new foliage and rose buds.
- Rust – Again, just like the name, rust colored spots appear mainly on the undersides of the rose leaves. Rust can be treated like black spot with an application of dormant oil and lime sulphur.
Neem oil is a new product that promises to get rid black spot, mildew, rust as well as many rose insects too. It is derived from the Neem tree.