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How to Treat a Magnesium Deficiency

If you notice the outer edges of your plant’s leaves are yellowing, you may very well be dealing with a magnesium deficiency. While this post will treat the deficiency in cannabis plants, the technique can be used for any plant that is showing these signs.

Magnesium Deficiency in Plants

A magnesium deficiency is characteristic of older leaves beginning to yellow and then slowly the entire plant yellows, if not corrected. You may also notice other leaves darkening their green color or even turning to purple. Ultimately, the plant will die if the deficiency goes unnoticed or uncared for.

Most commonly, one will encounter these issues in soil that’s lacking nutrients and organic matter. But don’t panic, there’s a simple solution to help you improve the health of your plants quickly and increase organic matter in your soil! 

Treating a Magnesium Deficiency

First you will need to mix together the below in a Chapin sprayer:

Depending on the size of your garden, you may find you need to double or even triple the above inputs.

Prior to spraying your plants, please remember that you want to spray when you are able to turn the lights off immediately after spraying. If you cannot turn the lights off immediately after spraying, you will inevitably burn your plants and weep on the floor of the growth you once had when you return to check on them. And, we don’t want that.

The easiest time is a few minutes before the lights go off for the day. Then there is no disturbing or changing the light cycle, just a light rain before the sun goes down.

Alright, now that you have found the optimal time to spray them, spray the plants with the solution you stirred up! You will want to be sure to cover as much of the plant as possible with the solution.

healthy cannabis plants after magnesium deficiency

Let the plants do the hard work from here.

After a few days, if you see small improvements, but not much, you can reapply after seven days and the plants should begin to bounce back at this point if they haven’t already.

End Result: Happy Plants

Getting to the Root of the Problem

While the plants will start to perk back up and look healthier, you still need to check all other growth factors to figure out what in your growing environment is causing the deficiency to occur. This will allow you to uncover the root of the problem instead of continually having to correct deficiencies in the garden.

One likely cause, as mentioned earlier, is a nutrient-lacking soil. If you suspect your soil is less than optimal, go pick up some fresh organic compost to top-dress the soil with. This will add plenty of nutrients back into the soil for your plant.

Just be sure to continue to topdress, use earthworms, and other amendments to continually feed your soil and the plants you grow, otherwise, deficiencies are bound to arise at some point or another.