When do you recommend applying dormant oil spray to piñon pines with scale in the Santa Fe area?
Answer: Hi P.F.,
We diagnose Pinon Needle scale as black dots that suck the moisture from the needles causing them to brown and fall off. Although this is deadly, it is a slow death taking at least a few years of unsupervised sucking un@l all the needles are gone.
We spray dormant oil on Pinon Trees to control scale when we start seeing ac@vity (this year late January) and we use it un@l Lilacs bloom (this year early April). How’s that for a scien@fic answer! There are other factors we consider as well. The temperature has to be above 40 degrees and below 85 degrees. If you miss this window (and by now you have), all is not lost. Look for white coNon-looking masses on the crotches and under the limbs of your tree. That’s their home. Get rid of it! If it is heavy and you can reach it, brush it off into a trash can then using a hard stream of the garden hose, hose down the tree and knock that yucky stuff off. The scale on the needles are a done deal but if you get rid of the home, you get rid of the heavy popula@ons. Be sure and hose the trunk down regularly but especially in February, March, and October. If you can keep it clean, you may never have to use dormant oil.
Please let me know if you have any other ques@ons or if there is anything else we can do for you.
Thank you …
Camille Certified Arborist