'What Orchids Eat', importance of calcium

[tucker85]

When I read the article ‘What Orchids Eat’ by Rick Lockwood, two points I took away from it were that calcium is a very important mineral for growing healthy orchids and that potassium blocks the uptake of calcium. I realize he was talking about the possible long term toxicity of excess potassium also, but I’ve heard several growers talk about the importance of calcium recently, so I keyed on that point. Our water has lots of calcium in it but one expert told my orchid society that the calcium in our water is not a type that is readily available to plants. Rather than using a low potassium fertilizer, I started applying a calcium/magnesium supplement, at first once a month, and more recently twice a month. I do not mix it with fertilizer so there’s no potassium in the mix. After using a calcium/magnesium supplement for almost a year, I’ve noticed two improvements in my plants. One, the bud drop problem that has plagued me for years has almost completely disappeared. Second, the fungus problems that I've always had during long rainy summers in South Florida have been non-existent this year. I know this is only antidotal evidence, but I've been very impressed with the results so far. The product I use is called MagiCal and it’s designed for hydroponics. I use it at 1 teaspoon per gallon, twice a month, by itself. Not mixed with fertilizer. I think it’s worth a try, especially if you have problems with buds failing.