Question
I have a ficus tree in a 20 (maybe 30)gallon pot; the leaf span extends past the edges of the pot (maybe 4 inches or so); it is about 4.5 feet high; I don't know when it was last repotted (I inherited the plant); it had been in a very dark hall, but I've moved it to a room that gets good, diffuse light.  It is dropping fewer leaves now than before.

The symptom that has me stumped is the sap all over the leaves.  Is this sap a sign of distress?  Or is it normal?  If this sap requires a remedy (or a preventative), what might that be?

Thanks much for your help,
Marie Kolbe Zamora


Answer
Hi Marie,

Stickiness on Ficus leaves is a sure sign of a scale insect infestation. Scale can be hard to detect. When they are young these sucking insects are slightly oval, slightly raised, translucent bumps about an eighth of an inch long. They can be found along stems and on the undersides of leaves. They don't look like bugs and don't appear to move. As they get older, they develop a hard, dark brown shell and look like a small mole. As the infestation increases, these sucking insects will secrete a sticky substance called honeydew that falls onto leaves, furniture and floors. This stickiness is the most obvious sign of scale and the one that most people notice first.

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. (You may want to do the spraying outside to avoid the dripping onto the floor). 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.

I do not recommend any pesticides because they are all hazardous to use and not 100% effective against scale. The best non-toxic treatment for mealybug and scale is called Brand X Foliage Cleaner. It is available through Southwest Plantscape Products in California (ftp://ftp.southwestplantscape.com/Brandx.pdf). Their phone is 1-800-333-7977.It is a silicon-based product so it is very slippery. Its ability to penetrate is probably the key to its effectiveness because it gets into the tiny crevices that other sprays miss.

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.

Soap sprays are not as effective as some other treatments because soap doesn't always penetrate the hard outer shell of the scale.

Increasing the light was a good move. The more light Ficus tres get, the better they do.

The pot is very large for the size of the tree. It will never need to go into a larger pot, so repotting will never be an issue for you.

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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