What is on my leaves?! Powdery Mildew! Yuck!

Yucky, yucky, yucky. Powdery mildew.


What is it you ask? It’s a fungal disease, that typically begins on squash or courgette plants, but that no plant is immune to. So bearing that in mind, it’s useful to know how to treat it! As even the best gardener may have a powdery mildew attack.

How do you know if you have powdery mildew? Well, your plants will basically look like the above photos. The surface of the leaves, or underneath, or steams even, will be covered in a silvery, grey powder. It is quite matte and makes it look like your plants have died when you look from afar which often causes gardeners to have a panic attack until they get closer and notice that it is powdery mildew.

It’s important to stop powdery mildew from spreading as quickly as possible, as it can potentially stop a plant from fruiting and can cause the leaves and plant to die.

As you can see in the above photos, the powdery mildew spread between my courgette plant to my squash plant while I was away for the weekend. Powdery mildew is very common when there is hot humid weather, but watering the leaves of plants actually helps to spread this disease. So in humid weather especially, make sure you are just watering the base of the plants. Dry plants, crowded planting, or poor air circulation also helps to spread this nasty fungus, so ensure that your plants have enough room when you are planting them and that you are watering them well in the hot summer months, as this acts as a preventative measure! As a general rule, water the base of the plants in the mornings, to help prevent powdery mildew from getting a hold.

So now you know the most important things about powdery mildew, what exactly are you supposed to do if your plants get powdery mildew??

If just a few of the leaves are affected, pull those out quickly and dispose of them. This helps to remove the fungus, but can also improve air circulation as the plant is getting slightly pruned. If the powdery mildew has spread to most of the plant (like what happened to my babies), using a baking soda spray (an inexpensive, and not dangerous fungicide) is something that really helps. It can also be made organically!

The basic “recipe” for this is

  • 1 Tbsp baking soda
  • 1/2 tsp liquid soap (not detergent)
  • 3.8 litres of water (1 gallon)

1. Mix the ingredients together in a spray bottle or watering can.

2. Spray this onto leaves of the affected plant when the plant is in shade (in the evening is ideal).

3. Ensure that the plant has been watered the day before as well so that the plant isn’t too thirsty when you are spraying it with the mixture. This can be repeated every one or two weeks, depending on how your plant is going.

4. Make sure that you don’t store the unused mixture though as it is more effective when used straight away!

And hey presto! Your powdery mildew should start to disappear and your beautiful plants will become happy once more! Good luck and good riddance to your powdery mildew!

If you liked this post, check out some of my other gardening posts!

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s