Wednesday, June 18, 2014

Powdery Mildew Is Not My Friend

Tomato leaf with powdery mildew
It seemed to happen so quickly. The powdery mildew enveloped my tomatillo and started to spread onto my tomatoes. UGH!
Tomatillo leaf with powdery mildew
The tomatillo had been doing beautifully, full of ripening tomatillos. It broke my heart but the plant was so covered with mildew that it had to be pulled. We did gather a couple of dozen tomatillos so it wasn't a complete waste. The bad part is, the tomatoes are starting to get it too.

There's no mistaking the look of mildew on a tomato leaf. The dark area with yellow around it tells the tale. 

On some leaves the white mildew is more obvious.
In addition to the mildew, I have spider mites, those tiny littles pests that want to take over everything in my garden. You can see this poor leaf has both mildew and spider mites. See the tiny white dots in a cluster near the stem? That's the spider mites at work.

So I am learning from my mistakes. I should have cleared away the leaves from the bottom of the tomato plants to provide more air circulation. That would discourage the mildew. I should have pruned the tomatoes instead of just planting them and letting them go crazy. That would have resulted in a more open habit also allowing better air flow. I should not have let the tomatillo grow so close to the tomato for the same reason. I should have been inspecting my leaves more closely for signs of problems, at least 2 times per week. It really pays to get down close to the plants, to look closely. I've learned my lesson.

This is my second year with a vegetable garden and I have so much to learn. Last year I had no problems with my tomatoes. I did have mildew on my melons though. So here's what I did today in the garden to try to get control of this mildew.

I pruned all the affected leaves from the tomatoes and removed all the low level leaves too. Then I removed all the dead leaves and stuff from the ground too. I discarded all this in the garbage, not my compost pile because I don't want those tiny spores infesting my compost. 

Then I sprayed with Neem oil. This is something that is new to me but has been recommended as an organic insecticide and fungicide so it should help with both the mites and the mildew. It is made from the neem tree, and has been used in India for thousands of years. In addition to being used in the garden, it is also used to treat skin disorders like acne and eczema, it is used in toothpaste and shampoo, and for many other uses. It is not toxic to animals, earthworms or bees. 

The next thing on my agenda is spraying the melons with a combination of 1 tbsp baking soda and 1 tsp of dish soap in a gallon of water. I am told that this changes the ph on the leaves which inhibits the mildew from growing. There is no sign of mildew on the melons yet so this is a preventative measure I'm trying.

Hopefully removing the infected leaves, clearing the debris and opening up the bases of the tomatoes, along with the neem oil will keep the mildew in check.

The good news is, I picked 18 ripe tomatoes today! Oh, boy are they tasty.


  1. I hate powdery mildew, too! Don't let it get you down, though. In my experience we can be as prepared as we can but if the conditions are right the mildew will have it's way. Last year I lost all my summer and winter squash to it. I'm glad you had a tomato harvest to balance your frustration!

  2. This year I did an experiment with my zucchini and the evil powdery mildew. I tried milk and water. It worked great. About a 50/50 mix, misted on the leaves ASAP. Good luck next year.

    1. I'm glad to hear you had some success with milk. If left unchecked, that mildew will ruin everything! Thanks for the comment.