Eggshells and Epsom Salts

Wed. May. 29, 2019

Click below to listen to my 2 min. Garden Bite radio show:  Eggshells and Epsom Salts

Last week I talked about coffee grounds and what they may or may NOT do in your garden. Today, I’m taking a page from the University of Minnesota to talk to you about eggshells and Epsom salts.

So here I am to burst your bubble… and I found the perfect photo… from a Master Gardener in Canada named Robert Pavlis on his site Garden Myths

Eggshells have been touted as the preventive measure tomato blossom end rot. Bottom line is no, they don’t. While the disease is a sign of calcium deficiency, it’s not that there’s not enough calcium in the soil, it’s likely the uptake process through the root system. Calcium enters plants only through the actively growing root tips. Calcium moves through the plant and into the fruits along with water, via transpiration. Damage to roots and/or problems with water uptake and movement in the plant can limit the amount of calcium reaching the fruit.

Blossom-end rot is the most typical issue we see with tomatoes.

Sometimes, a great abundance of other nutrients in the soil (such as magnesium or ammonium) can also interfere with calcium uptake. One of the most important things you can do is to keep plants evenly watered. That means mulching.  Learn more from Cornell University on blossom end rot. One quick note for those of us in cold climates, planting tomatoes in cool weather, in particular what we’ve been experiencing this year (2019), can heighten chances of blossom end rot.

Epsom salts are best in the bath, not the garden, says the U of MN.  

Bath salts – lavender and rosehips – put this in your bath!

Epsom salts will not prevent blossom end rot. In fact, adding too much magnesium to your soil can actually prevent adequate calcium from getting into your plants, making blossom end rot even worse.

Bottom line – avoid adding any extra chemicals to your soil – even things that seem ‘safe’ – because you can easily do more harm than good.

If you google epsom salt in the garden, you’ll find a lot of misinformation. Unless you do a soil test and find that your soil is truly deficient in magnesium, don’t add Epsom salt! Here’s more from the Garden Myth guy, my Canadian friend (although I’ve never met him), Robert Pavlis!