| Q My greenhouse is at least 50 years old. It is made of redwood, and it looks like it needs some treatment. I suspect that the constant
humidity is responsible for its condition. Mold is growing on some places on the frame and
elsewhere the wood looks fragile. What can I do to pre serve the wood? How should I treat
it? What compounds can I use without endangering my orchids? A Redwood once was plentiful and frequently used for patio and green house applications, especially in California. The wood is really incredibly long lasting. I have seen stumps of trees still standing that were cut at least 75 years previously. This is why it was considered good for outdoor applications and was seldom, if ever, treated for longevity. Nevertheless, it does not last forever and 50 years is not a bad life span for the material. The wood, if untreated and showing rot, is not salvageable. It would need to have been treated at the time of installation. The only way to preserve what is left of your green house would be to remove the plants, the glass and the rotten pieces. Then you could reinstall new pieces of redwood and treat the entire greenhouse with a preservative before reconstructing it and replacing plants. This is quite a project and you may find that a new greenhouse is cheaper and easier on the disposition. — Ned Nash |
Reprinted, with permission, from "Orchids" - The Magazine of the American Orchid Society, January 2001.