Question
Hi Will,
My formerly beautiful ficus plant is infested with tiny black bugs - too small for me to see clearly. The leaves get covered with small, grey spots, then die and fall off. My roommate brought home a similarly infected plant, which she threw out long since - but I have been away for almost a month, and now see that the poor ficus has the same thing. Help! It's on its last leaves! Any advice?
Thank you,
Miranda

Answer
Hi Miranda,

The gray spots are a form of scale - an insect that doesn't look like a bug, barely moves, sucks the sap from the leaves, and can cause major defoliation.

The key to eliminating scale is to treat even the ones that you cannot see. That means thoroughly drenching all leaf and stem surfaces until they are dripping wet. It is also best if you repeat this treatment all over again in 5 to 7 days to catch any crawlers (the translucent young ones) that you missed the first time. After that, you should check your plant weekly to see if they return.

You may want to try spraying with rubbing alcohol that will help break through the hard outer barrier of the scale and kill it. Mix 1 part alcohol with 8 to 10 parts of water. Add a little liquid soap to help it spread.

Sun Spray Ultra Fine horticultural oil is also mixed with water and effectively smothers the scale. Complete coverage is important.

Another good non-toxic spray is Hot Pepper Wax. Its main ingredient is hot cayenne pepper that overheats the plant pests. There is an information website for it at www.hotpepperwax.com.

Finally neem oil works similarly to horticultural oil. It should be diluted with water and Pine Sol to couneract the onion-like odor. All of these are  available nationwide at plant and garden centers and also by mail order.

Important: None of these should be applied to plants in direct sun or in high temps.

YOu may want to prune back leggy branches and stems before you treat your Ficus. The pruning will make the spraying easier and it will help stimulate new growth.

Good luck and please let me know if any of this is unclear or if you have any additional questions.

Regards,
Will Creed, Interior Landscaper
Horticultural Help, NYC

You can E-mail me directly at: [email protected]

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