Every summer in the Treasure Valley, spider mites become one of the most damaging and least visible pests affecting ornamental trees and shrubs. They thrive in exactly the conditions we're heading into right now: hot, dry weather and stressed plant material. The hotter and drier it gets, the faster their populations expand.
The tricky part is that spider mite damage often gets attributed to drought stress or disease at first glance. The early signs — bronzing or stippling on the upper leaf surface, a general dullness to foliage that should look vibrant this time of year — don't look like an insect problem. But if you flip those leaves over and look closely, or tap a branch over a white sheet of paper, the evidence becomes much clearer.
Heavily infested trees in Nampa, Caldwell, and across Ada and Canyon Counties can experience significant defoliation within a few weeks if a population surge goes unaddressed. Arborvitae, spruces, and many common ornamental shrubs are particularly vulnerable. Junipers and honeylocusts also show up frequently in our calls during July.
If the foliage on any of your ornamentals has looked a bit off over the past few weeks, it's worth getting eyes on it before the problem compounds. We're happy to take a look.
Have you noticed any of your trees or shrubs looking unusually dull or bronzed this summer, even though they've been getting water?
#TreasureValleyTrees #NampaArborist
Close-up photo of stippled or bronzed leaves from spider mite feeding, ideally showing the underside with mites visible. A photo of a heavily affected ornamental in a residential yard — arborvitae row, spruce, or juniper — makes the post relatable and specific. Authentic photos preferred.
Canva text suggestion: "Spider Mites Peak in July: What Treasure Valley Homeowners Should Watch For" or "Dull Foliage This Summer? It May Not Be Drought."