Water Quality and Fertilizer for Orchids: Expert Advice

Water Quality and Fertilizer for Orchids

A reader named Wayne asks about using distilled water and a specific fertilizer blend for his orchids. He lives in an area with very hard tap water, so he uses distilled water at room temperature. His current regimen includes Grower Pro-Blend 19-18-16 at quarter strength plus two drops of Superthrive per gallon. He reports excellent growth and healthy leaves, and recently started using rainwater as well.

Expert Response

Leonard, glad you appreciate the site. It's hard to argue with success. I also live in a hard-water area. Plants need calcium and magnesium, which are absent in distilled water. I'm not familiar with the Grower Pro-Blend brand. If it contains calcium and magnesium compounds, it should be fine. If not, I suggest mixing about 40% hard water with 60% distilled or rainwater. I've heard from growers using reverse osmosis water that their plants decline over time due to the lack of calcium and magnesium, which are essential for cell wall development.