Question of the Week Number 2: June 28, 2018
“Neil, what’s attacking my Green Mound junipers? It’s happened really fast.”
Spider mites! Nearly microscopic, 8-legged pests that are more closely related to spiders and ticks than they are to insects. They’re so small you could put 20 on the head of a pin. They suck the very life out of a huge variety of landscape and garden plants causing millions of dollars worth of plant losses each year.
Here are the symptoms…
• Almost always start at the bottoms of infested plants, then work their way up.
• Leaves develop a characteristic tan mottling – tiny, light cream-colored speckles.
• Leaves become almost solid white.
• Leaves begin to turn brown and crisp.
(from this stage on it may be difficult to save infested plants)
• Very fine webbing may be visible in leaf axils (where leaves attach to plant stems).
• Plant dies as mite infestation spreads to adjacent plants.
Some of most common host plants…
• Cucumbers and squash,
• Sweet violets
• Almost any plant is susceptible, however.
Confirming the infestation…
• You can see the mites with low-power magnification.
• Thump a suspect leaf over a sheet of white paper, then watch for tiny specks to start moving about. Don’t be surprised if you see scores of them.
Ways to treat for spider mites…
• Spray both top and bottom leaf surfaces.
• Unfortunately, we no longer have specific miticides available at the consumer level.
• Look for general-purpose insecticides that are labeled for spider mite control. Your local independent retail garden center operator will be able to help you.
• You will probably have to make two or three treatments for full control. Check weekly to monitor mite activity on your plants.