With winter upon us the rose issues of the past summer seem to have occurred ages ago. If you had a difficult summer, with trouble from any number of insects or fungal diseases, a dormant treatment could be just what the rose doctor ordered. Taking this extra precautionary step now can really pay off once the weather warms.
Dormant oil or Volck oil are treatments that can be used during the dormant season to destroy any insect eggs or fungal spores. These oils work by smothering and thus killing various pests. Both oils are essentially the same, with Volck oil being the thicker of the two. Either oil will work well however, if your garden center has a selection chose the thinner dormant oil for warmer winter climates and Volck oil for colder winter areas.
Winter oils should only be used when youíre positive your rose plant is dormant. A good way to tell when your rose has reached dormancy is noting once the plant has lost all of its leaves. Spraying while a plant is still active can cause serious issues since the oil will smother your plant along with the unwanted pests and prevent it from functioning properly. Youíll also want to make sure you follow any temperature recommendations on the package. Spraying when itís too cold or too hot can cause poor results or severe plant damage.
Your rose should have been pruned in the fall for the winter season. If not you could always do this now, since itís always better late than never. Assuming youíve already pruned youíll want to choose either a dormant oil or Volck oil depending on what is available at your local nursery or garden center. All of these oil treatments will need to be applied with a reusable one gallon pump sprayer. These can usually be found in the same aisle that the oil treatment is located and are generally inexpensive. Since all products differ slightly, be sure to read the application instructions and safety information before beginning and follow them exactly as stated for both the oil product and the sprayer.
Youíll want to spray your entire rose and coat the mulch at the base of your plant. This will get rid of any insects or fungi that are hoping to ride out the winter only to reemerge in the spring. If your mulch is looking a little thin you could also apply an extra layer at this time, taking care not to pile it up against the rose itself. Now simply clean out your spray equipment following the instructions on the package. Also take care to follow any after treatment recommendations such as washing your clothes or taking a shower.
While dormant oil treatment isnít that exciting, itís always nice to know youíve got a head start on insect and fungi protection for next year. Itís one of the simplest and somewhat less toxic treatments as well. Now, once the weather warms you can just head outdoors and enjoy the show!