Epsom salt will cure all your garden woes. Sure it will. And if you believe that one, I have some beach front property in Arizona for you.
How about if I tell you that Epsom salt can cure some of your garden woes – when used properly? Now doesn’t that sound more like the scientific gardener you have come to know and love?
How Epsom Salt Works
Epsom salt is pure magnesium sulfate. Both magnesium and sulfate are macronutrients crucial to healthy plant life. Magnesium plays a crucial role in photosynthesis since it is the center of the chlorophyll molecule. It is also needed for germination and cell wall formation. Sulfate (a mineral form of sulfur) helps the plant make more chlorophyll molecules and helps release other soil bound minerals.
Do Your Plants NEED This?
Didn’t I just show you that Epsom salts are needed?
Yes, the molecules in Epsom salt are needed for a healthy happy plant. Needed but do you need to add any? Most likely not. Our Southwestern soils tend to be rich in all the minerals plants need for life. The reason most of the Southwest is a desert is because water is limited, not minerals.
Your Plants Will Tell You
Your plants will tell you what they need, if you learn to listen to their silent language. If the plant needs magnesium, it will take it out of the molecules of the older leaves or shaded leaves and ship it to the newly growing leaves. It takes it out of the area between the veins first and they will turn yellow.
Sulfur deficiency looks just about the same, with yellowing leaves, but instead of old leaves, the newer, younger leaves are yellowed between the veins, similar to nitrogen deficiency.
And just to make it more hard for all you newer gardeners out there – baby leaves, newly growing, are NEVER the same green as mature leaves.
Learn Plant Speak
Learn to listen to your plants. You will have to “listen” with your eyes. Plants are generally slow creatures. When it comes to lacking minerals, they take a few weeks to form their words. When they need water, or worse, you overwatered – they scream at you right now and in a hurry. But plant mineral needs are a quiet whisper for your attention. Let your eye become practiced at listening to what your plants are saying.
Epsom Salts – Official Answer and My Answer
Official Answer: Epsom salts should not be added indiscriminately to soil unless a soil test shows you that you need magnesium or sulfur. If you only need sulfur and not magnesium, then horticultural sulfur is a much better product to use.
Gardening With Soule Answer: Experiment!
If you are not sure what your plant needs, try this. Take a picture of your leaves. Place 1/4 cup of Epsom salt in 4 gallons of water and use that to water with. Wait a week. Take a picture of the same leaves at the same time of day. Compare. No change? You might need nitrogen instead. Leaves recovered? You nailed it. Print out and save those photos in your garden journal so you know what magnesium deficiency looks like next time. Before and after photos are a very useful tool in your garden “shed.”
One Final Use of Epsom Salt
You can use some Epsom salt in the bath to soak away aches after a long day of working in the garden. But only a palm-full and do not soak for more than 20 minutes. (Your palm will be the right amount for your body.) Excessive magnesium taken into the body through the skin can have a laxative effect.
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