My understanding is that in real research trials, added epsom salt made little difference. That being said, loads of gardeners swear by it. My understanding is that magnesium deficiencies are most pronounced in either very acidic or very alkaline soils. That also being said, be aware that there are soils that are overabundant in magnesium. Magnesium is locally high in much of the west and north, but tends to be low in the southeast U.S. Seems to me that before you salt your garden with light metals, it might be smart to get a soil analysis done.

I would be curious to the exact source of said excerpt. Not everything you read on the 'net is valid.

That said, I've never used Epsom Salts in my planting and I get great tasting tomatoes every year for the last 25 years.

Thing is, most of our soils have plenty of magnesium as it is. Plus it is relevant to know other minerals, calcium, phosphorus, potassium , sulfur, CEC. Soil with high CEC want lower numbers on magnesium, sandy soils will want higher number on magnesium.

Am not talking about container gardens, those are different. Ain't buying this recipe, internet full of those "no science need to apply " suggestions

It really depends on what your soil composition and fertilization programs is as already mentioned by lindalana. Miracle Gro's tomato formula adds 0.5% magnesium (from epsom salt, which means they use about 5% additional epsom salt as filler in it) among a few other adjustments from the basic plant food. Tomatoes can be magnesium hogs here where I live if anyone used the ground to grow LOL, since it is relatively low in magnesium and built on a calcium base.

If your soil is played out, magnesium is likely first to go, so you could potentially get great results with it, but it is not working miracles in isolation ... it's because you are running a deficiency. If you have a good fertilization program it should already contain all the elements you need unless it is designed specifically to use epsom salt as the source of magnesium. That said, epsom salt is one of the safest additives if you just want to try it in moderation. If you use more economical dolomitic lime, you can do without it, but that requires time whereas epsom salt is immediately assimilated, being completely soluble over a broad range of applications.

PC

As it has been already mentioned, your soil might be rich in Magnesium already. On top of that most synthetic fertilizers (such as MG Shake n Feed) has some Mag.
But Magnesium is Epsom salt is a quick acting one. It is like fast calories in sugar, rather than in protein.
So I also use some Epson salt early on. Mag from Epsom salt , being highly water soluble, is depleted and leached fast , just like Nitrogen acts. So it won't hurt to replenish it. The best way is to go easy with it, like one TB spoon in 2 gallons of water, Maybe less.
That is how I do it. YMMV

Sey

Since i had nutrient deficiencies, I used it along with fish emulsion with every watering. I even foliar fed with same mix. I also changed from bottle water to my hard water (iron). These changes added mag/N/iron and it worked to green them up. I don't add it outside in the soil because mag is already high (optimum).

I have never used Epsom Salt on my tomatoes either - it sounds like most tomato growers on this forum don't. If there is already enough magnesium in most soils - that would explain why. I'm surprised more container growers don't need the extra magnesium - but maybe the fertilizers they use include it. If I had more time and interest I would grow one plant with Epsom Salt and see if there is a difference. Wished someone else would tackle that assignment for me - but if there are no takers - I may have time another year to do a comparison.

Yeah. Most not all fertilizers for garden vegetable have some Mag, especially the ones that are targeting tomato and pepper growers. .

Sey

Hi Hudson, I have used Epsom salts in my containers and it certainly didn't hurt. Not sure if it helped either. I'm planning on trying it again this year with a few plants to see if it makes a difference.

Sometimes an overdose of one thing can block the uptake of some others. I am not sure about Mag.
I am also a container grower. I use dolomitic lime which has some Magnesium in it.
Container growing is a different ball game and it is more challenging than in ground growing. The difficulty arises from frequent watering and by that leaching out a lot of nutrients, especially those that are highly water soluble, like Nitrogen and mag in Epsom salt. Smaller the container, the more challenging it gets. For example a 3ft x 6ft raised bed is just a big bottomless container but it acts more like in ground bed. Also because you put organic matter in it, it holds nutrients better, longerJMO

Sey