Plant Doctor – Powdery Mildew on Plants

The doctor is in, and here to answer your pressing plant problems! Are you a newbie gardener who needs help with your houseplants? Our new plant doctor series provides useful knowhow about how to care for your houseplants and nurse them back to health.

Noticed white or greyish powder appearing on the surface of your plants, such as the leaves and stems? The likely cause is powdery mildew, which is a common issue for plants in areas with high humidity. A fungal disease, powdery mildew is not fatal to plants unless it spreads extensively. Besides stressing the plant, the disease may also spread to other neighbouring plants.

What causes powdery mildew, and how to prevent it?

Conditions that lead to mildew formation include high humidity, low light and poor air circulation. Plants placed in damp, shady areas are most susceptible to this problem.

Here are some preventive steps to minimise the risk:

  • Choose healthy plants, or more resistant varieties when buying new houseplants
  • Avoid crowding your plants so they get ample air circulation
  • Avoid watering your plants from above so that the leaves do not get wet
  • Ensure your plants receive sufficient light throughout the day
  • Do not over-fertilise your plants, as new growth is particularly vulnerable
  • Prune away dead plant material regularly

How do I control powdery mildew?

While there are many commercial fungicides available to remove or contain powdery mildew, an organic or homemade remedy may work just as well! There are various homemade recipes you could try including baking soda, vinegar and milk.

Baking soda works especially well as a preventive cure. Just mix 1 tablespoon of baking soda with 1 teaspoon of liquid soap and 1 gallon of water. You can also add another tablespoon of horticultural oil or substitute it for liquid soap. Spray the mixture on your plants about once a week.

Alternatively, you can mix 1 part milk to 2 parts water, and spray the mixture on your plants every 1 to 2 weeks.

Feel free to leave us a comment below on more topics you would like to read about, or share your gardening experiences with us!

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