Bloom Buster Fertilizer....To Use or Not to Use?

[Andrew]

Originally Posted by cb977

Orchids really don't need that big boost in potassium...as long as you're giving them the nutrients they need on a regular basis. I add just a tiny bit at one feeding every two months or so...just out of habit...and because I have it here from before I learned it's not needed.

I, as well as a number of others, have had great success using the MSU formulas offered by Ray at Welcome to First Rays Orchids

If you look at the NPK's of the MSU fertilizers the phosphorus is very low, which was my point. The phosphorus requirements of flowering orchids can be met with most fertilizers. I can't imagine why you'd need phosphorus at that high a concentration unless the water/media's pH was locking the phosphorus up or the fertilizer was cheap and contained a substantial proportion of insoluble phosphate.