How are Epsom salts Magnisium Sulfate) used in orchid culture?
Epsom Salts (Magnesium Sulfate) and Orchids
Orchids need a variety of trace minerals, one of which is magnesium. Magnesium Sulfate is essential for the manufacture of chlorophyll, and using Magnesium sulfate will produce a more robust plant. One study previously posted on the orchid forum in 2002/2003, found adding Epsom salts does not make any difference in the size of flowers produced, but in an experiment the use of Epsom salts brought seedlings to maturity and flowering faster than those which were not provided with magnesium sulfate in the form of Epsom salts.
A variety of frequency and amounts of Epsom salts has been suggested for orchid growers. Mr. Bert Pressman, in an article entitled Care and Feeding of Orchids suggests using ½ teaspoon per gallon every time the plant is watered. Other advice offered here for phal growers has been 1 tablespoon per gallon, four times a year, or the same rate in the water during September and October (early fall) to assist in the budding of the plants.
Some orchid fertilizers contain Magnesium, such as Peters Cal-Mag fertilizer (2% Magnesium 5% calcium with a regular 15-5-15 N P K fertilizer, and the Dyna-gro lines Mag-Pro which are available in the U.S. Check the list of minerals to determine if the fertilizer you are using contains Magnesium. Epsom Salts diluted in water offer the same ingredient for much less cost, but some may prefer the other products for ease of use if nothing else.
Epsom salts are inexpensive and can be found at discount stores, drug stores, grocery stores, among other places, in the first aid depts.. Yesit is the same stuff you use for soaks!