Cannabis leaf edges and tips turning yellow? Copper deficiency can cause dark, shiny leaves with purple or blue undertones. Learn how to spot and treat it!
Plant Problems Symptoms: Dark leaves
Does your plant have "the claw?" The talon-like leaves that are bent at the ends are a sign that your plant may have nitrogen toxicity. Learn how to fix it.
Phosphorus deficiencies cause dark splotches on leaves and can appear at the bottom of the plant on some of the oldest leaves. Learn to spot & fix the issue.