Magnesium therapy seems to have worked a miracle. If it had been sunburn, the color would not have turned back to green like this, right?
I gave them two douses, about 5 days apart at 1tablespoon Epsom Salts (magnesium sulphate) per gallon. The last was the day before I left on my trip, 11 days ago, and the color recovery today is very evident.
See for yourselves - the little catt is much better, esp. the one leaf on the lower left, and a couple of my brassavolas that were fairly red as well have also recovered nicely.
Here's the "before" shot of the little catt for comparison.
