Does Horticultural Charcoal Accelerate Plant Growth? (A follow-up video of my experiment)

Описание: Previous video:    • How to use Horticultural Charcoal for Hous...  

It’s been five months since we talked about using Horticultural Charcoal for plants. So, this will be a follow-up video from my previous video ‘How to use Horticultural Charcoal for Houseplants’. As I mentioned in my previous video, they say there are several benefits of using Horticultural Charcoal. However, most of the claims are hard to prove because we can’t really see whether it increases airflow and aeration of the soil or protects the roots from rot. So, the one question that I wanted to get an answer to was ‘Will it accelerate plant growth?’ because that is something that I can check with my own eyes.
So, for the past five months, I cared for these two snake plants in identical environments. I placed them in an east-facing window spot for the entire time. And the only difference is that one is grown with Horticultural Charcoal mixed in soil and the other one is grown in regular potting mix. However, I was obsessed that I had to water the same amount of water to both plants, and I gave 150 ml of water every two weeks. As a result, I ended up underwatering the plants. You can see brown spots drying out on both plants. This is a sign of underwatering. In addition, new pups were emerging, and this also seems to have affected the mother plants drying out.
Nonetheless, I think it was a fair experiment. Overall, I'm not convinced that using horticultural charcoal will speed up plant growth. Both plants have brown spots due to lack of water. And the one grown in regular potting mix is producing its second pup.
Maybe in overwatering conditions, using horticultural charcoal might have more benefits because they claim that it can absorb excess water, but I will leave that for future studies.