‍ Epsom salts used to be the popular “put in the hole with your plant” fertilizer. The idea behind this is that Mg is deficient in soils.

In Saskatchewan, in a garden Mg is very unlikely to be deficient. It’s the 8th most abundant element in the world. With the earths crust holding 2%. However, abundance doesn’t always equal bioavailable.

Bioavailability is essentially whether or not something is “digestible”. Think of milk for example, there is lactose free milk and regular milk. For some humans lactose free milk is the only “digestible” form of milk.

What Decreases Magnesium Bioavailability:
Soil pH
Excessive levels of NPK
Soil moisture (too high or too low)
Stressed plants

Only way me can help a plant get Magnesium (which we know is used in chlorophyll production & oxidative stress protection) is via foliar feeding.

Foliar feeding is nutrients in a mist form that hit the leaves and not the roots.

Now…. Here is the interesting part. Only some nutrients can be uptake via this mechanism. And some plants are better than others when it comes to the job.

Uptake via stomata does happen… but it’s not the main mechanism. It is actually the leaves themselves. Problem is leaves have a cuticle and we need to power through that, which is why we use surfactants.

The pH of the spray helps because #osmosis in theory we know pH has an affect on pH. And plant biomass testing shows that pH of the foliar spray matters. This is also the reason why uptake is better with other nutrients outside of Magnesium. Having a broader spectrum foliar spray is helpful.

Soooooo… does epsom salt spray work? Sure. And I am happy supporting the use of it if it means keeping it out of the soil.

But remember it’s not the most effective & this is why even “professional” & commercial foliar sprays are few and far between. I’ll link to an option in my stories.

https://amzn.to/4bDzrsQ

#epsomsaltfertilizer #epsomsalt #epsomsaltspray