Dormant Sprays
Being Proactive and Environmentally Conscious by Using Dormant Sprays
Most people use dormant oil sprays in February. I like to use dormant sprays two times a year. The first application in November, once the leaves have fallen off, and the other in February. November gives us great weather to apply and if for some reason we can’t apply in February then at least we have one application done. I have had too many Februarys that have been too cold or the days that is nice, not being able to apply because of other obligations.
The ideal temperature to apply is 50 degrees and at a time of day that it has a few hours to dry before it turns cooler. The best way to apply is to use a hose-end sprayer. A pump or trigger sprayer could be used, but is time consuming and the coverage isn’t as good.
A dormant oil is sprayed onto a deciduous tree or shrub to prevent fungus or insects. The oil that is used is light enough not to damage the plant, but heavy enough to smother fungal spores or insect eggs.
Even though dormant sprays will prevent a lot of insects from hatching, the most recognized is the worm that eats the apple. The fruit is put there by nature for the larvae after it hatches so it eats its way out of the apple before turning into a moth/butterfly. Spraying the tree before it flowers and the insects have hatched will prevent apples with worms.
Another recognizable insect is scale. Scale has a hard shell surrounding it that prevents other insecticides to penetrate, but the oil will suffocate the scale.
Horticultural oils are derived from mineral or vegetable oils, and could be labeled as all-season oil or dormant oil. Neem oil is another type that could also be used as a dormant oil. It is a great natural or organic way to prevent certain pests in the yard. Dormant sprays have a low toxicity and are not harmful to the environment
Using dormant sprays in was more popular in the past than it is now. However, it is sometimes the best solution, but you need to be proactive. Because it is in the off season, we never think to do it.
I would not use the dormant sprays on any evergreen, maple or redbud. Using dormant sprays on these plants could cause injury or discoloration.