Holly ‘Sky Pencil’ – Euonymus Scale
Q: What is going on with my ‘Sky Pencil’ holly? Thinking that it has scale, I drenched it with systemic insecticide. Can I save it?
A: Yow – the holly is “Kivered up wiv it”!!
Your diagnosis is correct: scale insects. This is not connected to the landscaping done nearby.
It looks like euonyus scale…..which I usually control by cutting off the entire limb and regularly spraying horticultural oil on the newly emerged foliage.
But for your ‘Sky Pencil’ I hate to recommend cutting out the limb because it will disfigure the plant severely.
Here’s what I’d do:
1. Immediately spray the entire plant thoroughly with horticultural oil (SunSpray, etc). Be sure to get the spray under all leaves and onto all stems.
2. Hunt at garden centers for a systemic insecticide containing disulfoton (Bonide Systemic Granules is one). Apply according to label directions
3. Spray monthly with horticultural oil during the warm months for the next two years.
If the infested limbs are not too badly damaged, they may put out new leaves. If you see no leaves on them early next April, cut them out and hope the holly can fill the open space with foliage from adjacent limbs.