Tip the scales on these tiny suckers.
The next time it’s warm enough to venture outside, take a minute to examine the leaves of your camellias. If you’re lucky, you’ll see nothing but healthy, green foliage. But if you’re like most of us, a close look will reveal leaves with yellow splotches on the upper surfaces. Turn over the leaves and you’ll spot white and brown specks attached to the undersides.
Congratulations! You’re the proud owner of the camellia’s most common pest – the tea scale.
As a group, scales are interesting – and often very destructive – insects. Tiny, immature scales called “crawlers” walk on six legs until they locate a suitable leaf, twig, or trunk to feed. Then they insert feeding mouthparts into the plant to suck sap. They drop off their legs and remain in place for the rest of their lives. Many scales, including the tea scale, build a hard shell over themselves to protect them and their eggs from predators. This shell also shields them from contact insecticides, so ordinary sprays just don’t work.
Male tea scales are white. Females are brown. Severe infestations can kill a camellia, but usually the result is just a sickly-looking camellia that doesn’t grow well. Systemic insecticides, such as acephate and imidacloprid, will kill scales, but what if you’d like a more “natural” solution? Then follow a three-step strategy that’s worked well for the Grump.
WATCH: Grumpy Gardener's Guide to Camellias
Inspect your camellias this winter. Pick off all splotchy leaves, toss them into a bag, and throw it out with the trash. Don’t worry – this won’t hurt your camellias a bit. Those splotchy leaves would have dropped anyway. What you’re doing here is removing thousands of eggs before they can hatch into crawlers and move to healthy leaves.
Some infested leaves may be out of reach. Spray the undersides of these leaves with horticultural oil mixed according to label directions. The oil will coat the scales and smother adults and eggs. Go ahead and spray the rest of the leaves too, in case you missed some infested ones.
Repeat the oil spray in early May. This will kill crawlers that haven’t yet set up shop and those that already have.