Is Epsom salt good for orchids?

[talyce66]

I know that epsom salt is wonderful for many plants. For our staghorns, we sometimes blend epsom salt, bananna peelings, and water together and pour it on them. We heard that from The Garden Rebel, an expert in the remote area. Then I read somewhere that it is good for orchids. I tried approximately one tsp per gal of water. Of course this happened to be right around my routine fertilizing. Should this be a replacement or is it safe to fertilize?

[Charles]

I have yet to use salts. I do not know. Great question though. I am looking forward to learning something here. But in a word, yes. Some people use epsom salts in their care routine. How much and when I do not know.

[Ross]

Some growers profess to use Epsom Salts on Phalenopsis. I have never used the salts or even thought I needed them, but some do.

[markr]

Orchids, like all plants, need magnesium. Magnesium makes up something like 1.5% of a plant's dry weight (not sure about orchids specifically though). Some places have enough magnesium in the tap water to satisfy an orchid, and many specialist fertilizers include it. If not, or you use RO water, you'd want to supplement some magnesium and the most convenient source for many people is epsom salt.

Check your local water analysis and read the label on your fertilizer of choice, then decide if adding magnesium is something you want to try. Don't overdo it, orchids don't need much, and magnesium deposits around the roots will not be appreciated.

[Lagoon]

I do use ES, It's a quick green up and helps to induce earlier blooming, But not as a regular routine. I don't use this to replace any fertilizers.

[Ross]

Originally Posted by markr

Orchids, like all plants, need magnesium. Magnesium makes up something like 1.5% of a plant's dry weight (not sure about orchids specifically though). Some places have enough magnesium in the tap water to satisfy an orchid, and many specialist fertilizers include it. If not, or you use RO water, you'd want to supplement some magnesium and the most convenient source for many people is epsom salt.

Check your local water analysis and read the label on your fertilizer of choice, then decide if adding magnesium is something you want to try. Don't overdo it, orchids don't need much, and magnesium deposits around the roots will not be appreciated.

What part does this play with Phalenopsis, and why do some recommend supplements of Epsom Salts for these? Just curious.

[markr]

Not sure I understand your question Ross, so forgive me if you already understand this, but Epsom Salts are magnesium sulfate. Adding epsom salts to plants is basically adding magnesium.

If you mean Why are epsom salts recommended for Phalaenopsis specifically, I don't know. I've never heard of Phals needing more magnesium than other orchids.

I've read there is a link between magnesium and phosphorous uptake, so perhaps that is why magnesium has the reputation as a "bloom booster". Don't know. I'm not a botanist so perhaps someone else could give the details.

[Bolero]

It's not a replacement for fertiliser but you could say it supplements fertlising. It greens up your leaves and I find that if my leaves (especially the older ones) are yellowing up a little I had some and it makes a big difference.

I use it about one teaspoon to two gallons and I use it about once every 6 months or so. But you can use it more often probably. I love the effect it has on the leaves.

As for flowering? I am not sure what the benefits are.

Or maybe I'm just deluding myself and I believe it's greener than it really is........but it is widely used.

[Ray]

Epsom Salts is magnesium sulfate septahydrate (MgSO4.7H2O).

Magnesium (Mg) is a critical structural component of the chlorophyll molecule and is necessary for functioning of plant enzymes to produce carbohydrates, sugars and fats. Magnesium-deficient plants show yellowing between veins of older leaves, and they may appear limp.

Sulfur (S) is a structural component of amino acids, proteins, vitamins and enzymes and is essential to produce chlorophyll, so a deficiency usually shows up as light green leaves.

As was stated, magnesium is in most municipal and private well water supplies, and most fertilizers contain sufficient sulfur. If you have a complete fertilizer, it is unlikely that you'll ever see deficiencies in either, and if you want to add it, do so in small quantities as a supplement to your fertilizer, not as a replacement.

The GreenCare MSU RO formula - probably the most complete fertilizer on the market - contains 2% Mg and about 0.1% S by weight, while Epsom Salts is 10% Mg and 13% S. That would suggest to me that if I wanted to add it, I should probably not bother using more than about 1/5 of the amount of fertilizer I use.

I have added more as experiments - one time I went as high as two tablespoons per gallon - and I ended up with the strangest "zebra-striped" plants.

One thing that is nice about Epsom Salts is that adding it does not affect the pH of your nutrient solution.

[talyce66]

Thanks for the input and info!