Contact Us
University of California Cooperative Extension Ventura County
669 County Square Drive, Suite 100
Ventura, CA 93003
Phone: 805.645.1451
Fax: 805.645.1474
Office Hours:
Monday - Friday from 9 a.m. to 4 p.m.
The office will be closed for the following holidays:
December 24-25 - Christmas Holiday
December 31 - January 1 - New Year Holiday
January 20 - MLK Day
Rose Virus
There are eleven known viruses that infect roses. And since all roses are propagated vegetatively (rootstocks, buds, cuttings), the viruses are propagated with the plant parts. Several of the eleven viruses can be devastating to roses, causing plants to be stunted, having deformed leaves, shoots and flowers, and/or fail to bloom. Companies that grow and propagate roses are aware of these devastating viruses and have instituted virus certification programs to rid their stock plants of most of them. However, some viruses do not appear to reduce growth and flower production, so are not so rigorously culled from propagation fields. These are the ones that are causing the symptoms.
Virus-infected plants cannot be cured. Once a plant is infected, it will remain so for life. In most instances, flower production is not affected. However, if symptoms become severe and the plant begins to decline, the plant should be removed. Keeping rose plants in good vigor by fertilizing, watering and maintaining pest control will help reduce symptoms in some cases. In the meantime, you need to remember that viruses can be transmitted by pruning and cutting shears. Virus-infected plants should be pruned last and/or have their flowers harvested last. To be extra cautious, wipe your cutting shears with alcohol (rubbing alcohol is good) or a 10 percent bleach solution between plants.