Magnesium Sulfate for the Garden

[Mackay]

I found a big bag of magnesium sulfate on sale a while back and still haven't used it... essentially its the same as epsom salts.

How would you use this in the garden? should I just sprinkle some into the lasagna layers I am making now, make a water of it to water plants with.

What would you do? and are there any types of plants that should not get some?

 

[lesa]

I usually put a handful of epsom salts in the hole for my tomatoes. Not sure if it should be spread all around...

 

[Ridgerunner]

I took this from what I think is a competing website, so I won't give the link. The comments about how fast it leaches out are interesting. That is something I did not know. I usually sprinkle about a tablespoon of Epsom Salts when I plant my tomatoes and mix it up some before I set out the transplant. I us it when I plant a lot if things, beans, pepper, eggplant, whatever. Looks like I should maybe consider sprinkling a little later in their life. My soils analysis showed I was near the lower range in magnesium but not that I really needed it. One of those little bags from Walgreens usually lasts me all season.


To get an accurate reading of any deficiency, the soil can be tested, but in the case of magnesium, the results are quite variable. Magnesium content can deteriorate quickly, especially during rain or watering. Magnesium is quite water-soluble and gets leached to the lower layers of the soil easily. It is brought back up by tree roots. It is therefore important to return the falling leaves to the topsoil.

Unless you live in an area where the dolomitic rocks is dissolve in the water, you can be pretty sure that magnesium would benefit your garden, especially if you are not adding tree leaves. Magnesium shortage is a real problem in most parts of the world. It is caused when we water or irrigate instead of growing what is natural for the climatic conditions. It causes a serious calcium metabolism problem in people and animals, because calcium cannot be used without magnesium.

Extreme magnesium deficiency is recognized by pale green leaves and by blossom and fruit rot, but don't wait for that. Sprinkle dolomite or epsom salt on the soil from time to time, or add a little epsom salt to the water. Using a little frequently is better than using a lot once, because the excess just gets leached.


Epsom salt recipe: Dissolve 2 tablespoons of Epsom salt in 1 gal. of water. For healthy nightshade plants (tomatoes, peppers, eggplants) water just as flowering starts. Or use this mixture as a foliage spray in the garden and on house plants.

 

[lesa]

Very interesting, Ridgerunner. Even though I did add epsom salts to my tomato holes- I had a fair bit of blossom end rot. I think I will try watering with it, next year.

 

[Mackay]

Thanks so much. That clarifies a lot.

Since I do lasagna gardening and put in several layers of dicidious tree leaves I may not be needing magnesium for the beds but where I plant just out in the field I may.

Is magnesium something that corn plants may like? potatoes? yes, potatoes are nightshade...

 

[hoodat]

Magnesium is used by all plants to form chlorophyl but only in small quantities. It leaches out easily so is best used frequently at low concentrations. One way to make it a little more stable is to sprinkle it on compost each time it is turned. The critters doing your composting also need it so they will store some in their bodies and release it as they die. This makes it a little longer lasting when the compost is applied to a garden.

 

[dragonlaurel]

" Very interesting, Ridgerunner. Even though I did add epsom salts to my tomato holes- I had a fair bit of blossom end rot. I think I will try watering with it, next year. "

I started getting blossom end rot on my tomatoes and read somewhere that it was a calcium deficiency. I had powdered milk in the cupboard, so I made some up, and used it to water the tomatoes. The problem went away and I got good tomatoes off those plants for another month.

 

[Mackay]

Glad you told me that dragon laurel. I have a couple of packs of dried milk that have to be 15 years old I almost threw away... now I have a use for it.