Many cattleyas will bloom over winter and into early spring and when that happens – especially during the holidays – bringing them indoors is a great way to enjoy them at their best and add to the festive season.
If you grow orchids either in shade houses or under pool screens and you conscientiously fertilize and spray, chances are the chemicals and hard water will coat the leaves with residue that is chalky white. Cleaning the leaves before you bring the plants inside – or before you enter them in a show or judging – will definitely add to their beauty.
Additionally, I suspect that growth will be enhanced without that film. So I have begun an effort to keep the leaves clean while they are growing outside, not just when we want to make them show-offs.
Beer often is recommended as a cleanser, as are lemon juice, 7-Up, dilute Neem oil and milk. Milk must be wiped dry to prevent fungus.
Recently, I experimented with straight lemon juice, dilute lemon juice and full strength hydrogen peroxide on cattleya leaves. Straight lemon juice – applied without rinsing or wiping dry – left smears on the leaves the next day. Back to square one.
Dilute (50-50) lemon juice and water worked better, but I also carefully wiped the leaves with water-soaked cotton balls and dried them with paper towels. I worked on both the top and undersides of the leaves. On a different plant, I used the hydrogen peroxide (thinking any excess might deter fungus), but also wiped with cotton dipped in water and then dried the leaves with paper towels.
I don’t know if the photosynthesis is enhanced (although I suspect it is) but I know that walking into the orchid house is a more pleasant experience – and the work already is done before bringing them indoors. It remains to be seen how often this has to be repeated.
Here’s a look at the difference between leaves with chemical film, left, and those cleaned with dilute lemon juice, on the right.