If you think that your marijuana plant is lacking in magnesium and you are looking for a way to add it, a highly recommended option is dolomite lime.
You can buy it in nurseries and garden stores. It is a great source of nutrients that combines calcium and magnesium, and is commonly used in commercial crops.
Dolomite has a neutral pH of around 7.0 and will help buffer the pH variations in the soil and keep it in an optimal range for cannabis growth. Especially on acidic substrates.
Adding Dolomite Lime to your Soil
It is applied by sprinkling on the substrate, so it is absorbed very slowly. This can be positive or negative.
Positive because it will continue to provide nutrients over the months.
Negative in case you have magnesium urgency.
The finer the dolomite the faster its nutrients will be released.
- If you are growing in pots, sprinkle about 6 tablespoons per 4 liters of substrate above the ground.
- In case you are cultivating directly in the soil, take a handful and sprinkle over the soil around the plant. Take care to apply a thin layer and do not overdo it. Check out the example photo.
Then water with standing water, slightly just to moisten the lime and the substrate a little. The next few days you can water normally.
If you added it to fix the pH of the substrate, wait at least 1 week before measuring it again.