Tomato Leaf Mold

tomato leaf mold

Tomato leaf mold is a common fungus that attacks tomatoes grown in humid places. The mold attaches itself to the leaf and feeds off of the humidity to grow and thrive.

It is vital to take care of the situation immediately so that the foliage isn’t dramatically infected. Infected leaves will decrease the amount of tomatoes yielded.

Luckily, this fungus is pretty simple to treat and cure.

Causes and Symptoms

With this type of fungus, it is rare that the fruit is infected as well. The signs to look for are all on the leaves. The tops will begin to develop small, white, gray, yellow, or pale green patches. The underside of the leave will have a fuzzy feel that is purple in color. Sometimes the fuzz will be olive green. The “fuzz” is actually spores of the fungus.

The infected tissue becomes yellowish-brown and the leaf begins to wither, eventually falling off of the plant. Untimately the whole plant will wither and die.

In the rare case that the blossom or fruit is infected, the mold will appear as a black sore-like lesion. The black can grow to cover over half of the surface area of the plant or blossom. Tomato leaf mold affects ripe tomatoes as well as green tomatoes.

Treatments and Control

When you notice the infected areas, the first thing you can do is let the plants air out. If they are being grown in a green house, air exposure is a must, because the humidity that the fungus needs to survive is dried up.

If the tomatoes are being grown outside, try to keep from wetting the leaves when you are watering the plants. When you water the plants, earlier watering is optimal because it allows the plant time to dry when the sun comes, keeping humidity around leaves to a minimum.

Another option for treatment is fungacide sprays. When using these sprays, be sure to cover each part of the plant that is above ground, paying special attention to the underside of the leaf. Some of the most widely recommended sprays are those containing calcium chloride. There are some organic fungicides available as well.

Some remedies that can be mixed up right in your kitchen include an apple-cider and vinegar mix to treat the mold. Corn and garlic spray can be used to prevent the fungi outbreaks before they even occur. A milk spray is also a natural, helpful cure.

Comments from Other Gardeners
  • saucelover says:

    This is a great article! It answers every question that I had except for one: Where does it come from? I understand that it grows well in humid conditions but what causes it to begin with? And do I need to treat the soil too, or just the plant? I’m trying to learn as much as I can, and this is pretty prevalent in my area so I want to know what I can do to avoid it to begin with, besides not watering my leaves. Thanks a ton!

  • Steven Wrubleski says:

    For vinegar treatment, does anyone have specific concentration information? 100% store bought vinegar? (which is already diluted) Any testimonials? thanks – Steven

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