|My camelia has rust spots on the leaves. What do I do to prevent this?|
|Camellias typically do not develop the fungal disease that causes rusty colored spots (such as you might see on snapdragon, rose, or hollyhock leaves), but Eriophyid Mites can leave damage that might appear to be rust. Damage is caused by the mites? feeding on individual plant cells. The resulting abnormalities may show up as bud galls or blisters, a rust-like growth on the leaves, or browning of the leaves and bud scales.
Inspect both the upper and lower surfaces of several leaves for webbing and/or adult mites. A hand lens or magnifying glass is helpful. Look carefully at leaves that show any unusual color patterns. This is particularly important if the plant is not suffering from othertresses such as lack of water or plant nutrients.
If you detect mites, you have several control options:
If only a few plants are infested and you can reach the plants with a garden hose, it might be possible to wash the spider mites from the plants. Use enough pressure to thoroughly wet both upper and lower leaf surfaces. The water force may dislodge the mites or kill them. Water will not affect the eggs; therefore, repeat the procedure in 3 to 5 days. A third washing is helpful if the initial mite infes tations were large.
If chemical control is needed, spray coverage and repeat applications are important. Many of the miticides used must come in contact with the pest to achieve control. This means directing your spray to the undersides of the leaves where most of the mites are. Coverage may be better if you add a spreader to the spray mixture. This material helps spread the solution over the leaf surface. Remember to direct your spray where the pest is located. The miticides control adults and immatures but do not affect the eggs. It takes 2 to 3 days for eggs to hatch. This means you must make a second application to kill newly-hatched nymphs.
Best wishes with your camellia!