Sometimes, the best remedies are handed down from generation to generation and are practically free. Such is the case with Epsom salt, which has been used since the 16th century and currently sells for less than a dollar per pound in most drugstores. Consumers use the product for a variety of reasons – as a soaking aid for sore muscles and as a treatment for constipation - but by far its greatest contribution is in agriculture. Originally named after a town in England which has naturally occurring magnesium sulfate (MgS04) in the spring water, Epsom salt is used to fertilize thousands of acres of farmland each year.
Like most houseplants, orchids benefit from regular fertilizing. Roots, leaves, and flowers are at their best when exposed to not only the major nutrients, nitrogen (N), potassium (P), and phosphorous (K), but also to the lesser nutrients, including magnesium (Mg) and sulfur (S). These two elements alone make up nearly 25% by weight of Epsom salt. Many popular orchid fertilizers do not contain magnesium or sulfur, so a supplement is advised.
According to the Epsom Salt Council, the white crystalline “makes plants grow bushier, produces more flowers, increases chlorophyll production, and deters pests (including slugs).” Commercial orchid growers have been supplementing their feeding regimes for over a century and cite noticeable improvement in the bud count of their plants, particularly Cymbidium and Phalaenopsis.
The generally recommended application rate of Epsom salt is not based on exact science. A prominent brand suggests diluting 1 teaspoon of magnesium sulfate per gallon of warm water and applying it once a month. Some growers use ½ teaspoon per gallon with every watering, while still others use a higher concentration in the autumn to encourage blooming. A general rule is to err on the conservative side since orchid roots are sensitive.
The next time your family doctor prescribes a hot Epsom salt bath, be sure to set aside a few cups of the dry granules. By any measure, the trusted remedy will heal your aches and pains, as well as your orchids.