The cannabis sativa plant produces more cannabinoids when stressed. That’s a fact long known to growers seeking higher levels of THC and CBD.
Researchers found that stressing hemp with toxic soil actually boosted CBD levels.
Stressing plants also comes with risk. Stressed plants have a tendency to turn hermaphrodite—producing seeds and pollen rather than buds laden with cannabinoids. It’s the female cannabis plant that produces flower. That’s why only a reckless or foolish grower will deliberately subject their crop to extremes in heat, thirst, or other things that might freak a plant out.
But when low-THC hemp plants are stressed specifically by growing in soil contaminated with toxic heavy metals from coal mining, the hemp plants produce an abundance of CBD, recent research published in the journal PLos One has found.
And that CBD boost apparently happens without a boost in THC levels, which is critically important for hemp farmers. THC levels must remain below 0.3% for hemp plants to remain legal in Europe, Canada, and the United States.