Wastei
Well-Known Member
It's not very recommended to topdress with dolomite lime since the Magnesium part breaks down before the Calcium. The most common result is excess Magnesium in the medium. Depending on the source dolomite lime might even have more Mg than Ca and its therefore very important to check the listed content whenever you buy a new bag.
Traditionally it's used to topdress for added magnesium in late season and next year you have a well buffered soil since the complete content of the minerals been broken down. But this practice is strictly for outdoors and have no place growing in containers.
It takes weeks and even months for dolomite lime to fully break down and it's the magnesium part that breaks down first and becomes accessible to the plant.
This practice will cause changes and fluctuations in the Ca:Mg ratios that should be kept stable, alone and non changing throughout the grow. You get fluctuations by repeatedly topdressing a mineral that takes weeks to break down and will at that time change the Ca:Mg ratios back and forth.
This is a really big stressor growing Cannabis. As an organic grower you should already have your soil cooked, mixed and balanced enough to not need any topdressing and if you choose to do so it's important to do it in a safe manner that won't stress the plant out.
There's much better and safer alternatives than topdressing dolomite lime.
Hope that helps.
Cheers!
