Mold Can Ruin Your Cannabis Crop! Here's How to Get Rid of It
Updated: Apr 27
Mold can attack your cannabis plants at any time—when they’re seedlings, during flowering, and even after harvest. If you’re wondering how to get rid of mold on cannabis, it may already be too late. Once a plant gets moldy, there’s not much you can do to save it, but there are measures you can take to stop mold from spreading to the rest of your crop.
How to Get Rid of Mold on Cannabis: Ten Ways to Keep It Out of Your Grow Op
1: Regularly Check Your Plants for Signs of Mold
If you notice any brown buds, mushy stems, slimy roots, or a dusty white coating on your plants, you might have mold. Stay on guard and check your plants daily for any signs of mold. The sooner you catch any problems, the easier it will be to save the rest of your crop.
2: Remove Moldy Plants Immediately
Mold reproduces by releasing spores into the air, and those spores can travel fast and far, even without strong air currents. In fact, mold spores can travel as far as 8 feet at speeds of up to 55 miles per hour with no air currents at all. If you find mold on one plant, get rid of it quickly, and quarantine the plants nearby. It’s better to lose a few plants to mold than an entire crop.
3: Use a Fungicide
One preventative measure you can take to protect your plants from mold is using a fungicide. You can purchase a commercial fungicide that’s formulated for cannabis or take a more DIY approach and mix up a hydrogen peroxide solution. Spray fungicide on your plants before flowering or add it to your water if you’re growing hydroponically.
4: Repair Leaks
Moisture is a friend of mold, so keep leaks under control! If you have a leaky roof, leaking pipes, or leaks in your irrigation system, fix them right away. Leaks and water damage are the number one cause of indoor mold growth, so inspect your building and equipment regularly.
5: Check for Condensation
Mold loves a warm, humid environment, so keep condensation under control as well. Droplets that build up on windows, roofs, or air ducts can create puddles or moisture that seeps into walls and insulation. Keeping condensation under control will also help keep mold out of your grow room.
6: No Food or Drinks
A spilled drink or forgotten crumb can wreak havoc in a grow room. Like all living organisms, mold needs food to eat. If you’ve ever had a loaf of bread suddenly turn blue, or pulled a fuzzy lemon out of your refrigerator drawer, you know how easy it is for food to grow mold. Banning food and drinks from your grow room will help keep your plants safe.
7: Clean Regularly
Keeping your grow room spotless and free from dirt and dust will also help keep mold under control. Empty the trash daily, and clean containers and floors with an oxidate to kill microorganisms. Don’t sweep—brooms will only spread mold spores around. Use a hepa filter backpack vacuum instead.
8: Control Humidity
Keeping the relative humidity in your grow room below 60% will also inhibit mold growth. This may be more difficult with a hydroponic grow op, but using fans to keep your plants aerated and dry up excess moisture can help control humidity.
9: Try an Air Purifier
Using an air purifier to remove impurities like dust and mold spores from your air circulation will also protect your plants. Mold can feed on dust, and its spores can attach to dust particles that travel through the air. Eliminating dust and other contaminants from the air supply can also inhibit mold growth.
10: Get Professional Mold Remediation
My Pure Environment’s patented dry fog technology will destroy mold on contact and keep it from coming back. Our powerful surface sterilants create an antimicrobial barrier that resists contaminants, so your grow room will stay cleaner longer.
Mold Remediation for Grow Rooms in California
Whether you're growing medicinal marijuana or CBD plants in Santa Clara, our professional mold removal services will keep your operations free from mold. We’ll identify the source of your mold problem and help you prevent future outbreaks. If you’re wondering how to get rid of mold on cannabis plants, give My Pure Environment a call today.
Photo by CRYSTALWEED cannabis on Unsplash used with permission under the Creative Commons license for commercial use 5/30/2022.