Growing cannabis can be rewarding, but it comes with challenges. Nutrient deficiencies, pests, mold, and environmental issues can impact your plants. This guide covers the most common growing problems and their solutions to help you maintain a healthy, high-yield crop.
1️⃣ Yellowing Leaves (Nutrient Deficiencies) 🍂
🛑 Problem:
Leaves turn yellow, curl, or develop brown spots.
🛠 Causes & Fixes:
✔ Nitrogen Deficiency – Lower leaves turn yellow and fall off.
✔ Fix: Feed with a balanced NPK fertilizer (higher nitrogen in the vegetative stage).
✔ Calcium Deficiency – Brown spots on leaves, weak stems.
✔ Fix: Add calcium supplements like Cal-Mag.
✔ Iron Deficiency – New leaves turn pale yellow.
✔ Fix: Lower pH to 5.8–6.5 for better iron absorption.
💡 Check soil pH (6.0-6.5 for soil, 5.5-6.0 for hydroponics) to ensure proper nutrient uptake.
2️⃣ Overwatering & Underwatering 💦
🛑 Problem:
🚰 Overwatered plants have droopy, swollen leaves.
🏜 Underwatered plants have dry, crispy leaves.
🛠 Fixes:
✔ Water only when the top 1-2 inches of soil is dry.
✔ Ensure pots have proper drainage to prevent root rot.
✔ Use fabric pots to improve aeration and avoid overwatering.
💡 Droopy leaves can indicate both overwatering and underwatering—check soil moisture before watering.
3️⃣ Nutrient Burn (Overfeeding) 🔥
🛑 Problem:
Brown, crispy leaf tips that look burnt.
🛠 Fix:
✔ Flush your plants with pH-balanced water to remove excess nutrients.
✔ Reduce feeding to ½ strength and gradually increase.
💡 Less is more! Start with light feeding and increase as needed.
4️⃣ Pests: Spider Mites, Aphids & Fungus Gnats 🐜
🛑 Problem:
Small bugs, webbing, or holes in leaves.
🛠 Fixes:
✔ Spider Mites – Spray with neem oil or insecticidal soap.
✔ Aphids – Introduce ladybugs or spray with neem oil.
✔ Fungus Gnats – Use sticky traps and let soil dry out between waterings.
💡 Check plants daily for pests and treat early!
5️⃣ Mold & Bud Rot ☠️
🛑 Problem:
Gray or white mold on buds and leaves.
🛠 Fixes:
✔ Keep humidity below 50% during flowering.
✔ Increase air circulation with fans.
✔ Remove infected buds immediately to prevent spreading.
💡 Prevent mold by maintaining proper airflow and humidity levels.
6️⃣ Heat Stress & Light Burn ☀️
🛑 Problem:
Leaves curl upward, turn brown, or look bleached.
🛠 Fixes:
✔ Raise grow lights 12-18 inches above plants.
✔ Keep temperatures between 70-85°F (21-29°C).
✔ Use oscillating fans to prevent hotspots.
💡 If leaves curl up and tips burn, adjust light intensity and temperature.
7️⃣ Stunted Growth 🚫🌱
🛑 Problem:
Plants grow slowly or stop growing.
🛠 Fixes:
✔ Check root health – root rot or bound roots can slow growth.
✔ Ensure enough light – at least 18 hours of light in veg stage.
✔ Maintain proper pH – incorrect pH can block nutrient absorption.
💡 Healthy roots = healthy growth! Avoid overwatering and transplant if needed.
Final Tips for a Healthy Grow 🌿
✔ Monitor plants daily for early signs of issues.
✔ Keep pH levels in the right range for nutrient uptake.
✔ Use quality soil and nutrients for strong, resilient plants.
✔ Adjust light, temperature, and humidity for an ideal grow environment.
By catching and fixing problems early, you’ll maximize yield and potency for a successful cannabis grow!