Is Epsom Salt Good or Bad For Orchids?

The internet, it seems, has created for gardeners a bit of a conundrum. While it gives us instant access to all of the plant care information we could ask for, it also gives us more than a handful of misinformation. It also gives us an extra healthy dose of Old Wives Tales.

The thing about us “Old Wives” is that regardless of whether we understand the science of a thing, we usually know what works. We find out by trial and error, or advice passed down to us from those who ought to know, even if we can’t quite explain why.

The Long Answer

Epsom salt has long been touted as a remedy for many minor ailments that humans experience. It provides the body with magnesium which soothes tired muscles, reduces swelling, promotes more restful sleep. It also increases nerve function and energy production. But could it also be beneficial to our prized and delicate orchid plants?

The science says yes. Epsom salt is successfully used to fertilize the crops of hundreds of farms every year. It’s also highly favored by commercial orchid growers.

Epsom salt bridges a very important gap that most standard fertilizers don’t fill. When added to your orchid care routine, they can make a significant difference in the size and vigor of your plants. It can help add size and brightness to their precious blooms. 

Why it Works

Orchids love to be fertilized. In fact, during their growing season, you can fertilize with each weekly watering. It will soak it up and reward you handsomely with beautiful foliage and healthy flowers.

Most commercial fertilizers offer all the nitrogen, potassium and phosphorus your orchid could wish for. However, orchids appreciate a number of other nutrients, and among them are magnesium and sulfur. This is sadly lacking from most of these orchid fertilizers. This is where Epsom salt flexes its well-toned and highly functioning muscles.

Epsom Salt is a mineral composite of sulfur, magnesium, and oxygen. We know that plants remove carbon dioxide from the air and produce oxygen. While important for humans, oxygen is also very important to a plant’s cellular health.

For plants, more oxygen translates to larger, healthier root systems. With as delicate as their roots are, this is certainly a benefit to their overall health.

The function of sodium in plants is similar to its function in the human body. It helps to signal stress management and regulate the metabolic process.

In plants, it also acts as a vehicle for moving symbiotic bacteria and fungi. These are important for the overall health of the plant. They would otherwise not be bioavailable to the plant without the presence of that sulfur.

Finally, magnesium helps with the synthesis, production, transportation, and utilization of chlorophyll. To put it plainly, magnesium is what makes plants green. Without it, a plant’s growth will be stunted and subpar. It also activates enzymes responsible for growth, as well as contributing to the synthesis of proteins.

In addition to all of these benefits, Epsom salt helps to flush their roots clean of any salt buildup left behind by conventional fertilizers. It also acts as a deterrent for slugs and other garden and household pests.

To sum it up, the occasional application of Epsom salt will provide your plant with important nutrients that it needs to grow bigger, greener leaves, and produce larger, more colorful flowers. Whew! That’s a tall order for a product that might run you about $4 every 5 years or so. This of course, depends on how deep you are into your orchid addiction.

Making it Work for You

Let’s talk about two different methods of applying Epsom salt to your orchids. In my humble opinion, one is superior to the other, but I will include them both. You can decide which works best for your care routine.

Delivery Through Misting

Misting orchids with fertilizer is a common and effective practice. They have aerial roots which help the plant to absorb water and nutrients.

Misting delivers nutrients to these aerial roots, which typically grow from between leaf structures, so they provide a direct route for those nutrients to reach the foliage which grows farther from the central root system.

To carry out this application, mix 1tsp of Epsom salts in with 1gal. of water, pour it into a spray bottle and give your orchids a good, thorough misting. Do this every three months for best results.

Delivery Through Rinsing

If you recall, one of the benefits of using Epsom salt in orchid care is that it helps to rinse residual salt buildup from their root system.

Misting will not have this effect, however. You are unlikely to reach most of your orchid’s central root system in this fashion. Misting doesn’t do much to rinse anything away.

To achieve this particular benefit, take the same solution of 1tsp/1gal and pour it through the potting medium and consequently, over the central root system of the plant.

Their roots will absorb plenty of the solution in this way. You’ll also get the added benefit of a clean slate for those roots to get back to proper absorption of water and fertilizer. This also, should be carried out every 3 months.

A Combination

I know I said that there were only two methods, and perhaps you’ve already thought of a third method that sounds more efficient. I highly encourage you to incorporate Epsom salts in the care of your orchids in any way that works for you.

If you prefer to water your orchids with ice cubes, you can make Epsom salt cubes a few times a year. If you prefer to water by immersion, you can immerse their roots directly in the Epsom salt solution.

My recommendation is to combine misting with one of the other methods in order to deliver the valuable nutrients in Epsom salt to both the foundational roots and the aerial roots of your plant. Just be careful not to overdo it. Their roots are delicate, and it’s typically a good idea to err on the conservative side when introducing any new products.