White Fuzz on My Plants (Powdery Mildew)

Overview:

The type of white, fuzzy fungus that grows directly on your plants is most often referred to as ‘powdery mildew’.  It is a common fungal disease that impacts plant leaves and stems.  It’s different than the beneficial fungi you may see growing in your hydroponic media.  Powdery mildew attaches to your plants leaves and stems.  In most cases, it will not kill your plant, however It spreads rapidly and can have a negative impact on the growth and aesthetics of your plants.  Therefore, you will want to remove it.

Steps for Removing Powdery Mildew:

Step 1: Remove plant leaves with powdery mildew on them.  Because powdery mildew can be difficult to get rid of, and because it can spread quickly to other plants, you will want to immediately remove plant matter with visible powdery mildew. 

Step 2: Spray your plants with a natural remedy to remove any powdery mildew that you can’t see.  There are several home remedies for removing powdery mildew

  • Vinegar and water is a favorite.  It won’t leave any visible residue on your plants, and it works great.  Vinegar works to remove the mildew because it is highly acidic, and ultimately burns the mildew.  However, if your solution of vinegar is too strong, it will burn your plants as well.  Add about 1 teaspoon of apple cider vinegar to every 16 ounces of water in your mixture.
  • Organic Copper Sulfate/fungicide is another popular solution.  This will also burn your plants if the solution is too strong.

Keep a close eye on your plants for the next 3-5 days.  Continue to remove any leaves you see with powdery mildew, and re-apply your vinegar and water solution as necessary.  Unfortunately, some plants become so susceptible to powdery mildew that you will find yourself struggling with it for weeks or months.  At this point, it will be best to remove the infected plants, wait a week or more, and replant.

 There's more great growing information in the links below: