An organic solution to aphid infestations, and how to paint columns dating to 1927
BOSTON — Q. This year my plants are loaded with aphids, leaf-hoppers, and little black bugs. I've applied some insecticidal soaps, but without much success. Can you recommend anything else? I want to stay as organic as possible.
A. We've had such a wet spring that the bugs have really taken off, says Paul Parent, who hosts a weekly gardening talk show on WRKO-AM in Boston. "I suggest you wait until we get some dry weather, and there is no forecast of rain for at least 12 hours and apply an insecticidal oil spray, available at your local garden center."
Q. I am on our church maintenance committee and have been asked to repaint the hollow, wooden columns on the front porch of the church.... For the past 15 to 20 years there has been difficulty keeping paint on the columns.... The building dates back to 1927. My concerns are: Is the present ventilation adequate? What's the best way to treat the bare wood before repainting?
A. Venting is important, but it sounds like a good and proper paint job will do the trick, says Howard Clark, project manager for Warfield Services Inc., a commercial builder in Natick, Mass.
The iron support at the bottom is called a plinth block, and it's there to separate the wooden column from its moist footing so that the water will not be wicked up into the wood. It's also designed to allow air to pass under and up through the column. Openings in this base should be kept clear.
The top of the column should be flashed to keep out the weather but completely opened for ventilation into the soffit of the church structure - that is as long as the soffit itself is vented to the outside. There is, however, a way to check the ventilation.
When the sun is on the columns, extinguish a candle and hold the smoky wick near the plinth. A well-ventilated column will deflect and even draw this smoke. Ventilation can be added on the back side of the top plate or top collar molding if proved necessary.
But more likely, you're suffering from the cumulative effects of poorly prepared paint jobs that have allowed in, and trapped, moisture and mildew. Complete stripping is the way to go.
But beware; back in 1927 (in fact, until 1975) there was lead in paint, so this stripping should be done by someone trained in its abatement. A painter will probably suggest an initial coat of an oil-based sealer/primer. This way either oil or latex finish can be used over it. Perhaps, at some point, somebody put oil over latex, contributing to your problems.
Suggestion: Strip, prime, and paint a 2-foot by 2-foot section of the column. If the paint holds, do the whole column like this sample.
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