Tomato Blight: Is Gardening a Green Science … ?

I am curious. While removing and disposing of some tomato plants that had contracted the dreaded blight  I wondered if I should dispose of the remaining soil in the pots or would the UV rays from the sun kill any blight bacteria?

Tomato Blight
Tomato Blight

Apparently,  high UV kills COVID-19 virus on surfaces so why not blight, especially as we can have UV of 9 and even 11 here in the Algarve?

But then on further consideration, if the UV rays kill the bacteria why do they not kill the bacteria on the tomato plants?

No matter what precautions I take, every year is the same. If the plants were growing in the ground I would not be removing all the surrounding soil. Do you?

1. Do you remove the soil?

2. Allow the soil to rest before replanting with another crop?

3. Dispose of all the soil in pots or allow to break down in the compost heap?

4. Other – suggestions, please.

I don’t have green fingers or the green thumb so for me gardening is down to green science.


Tomato blight
Tomato Blight



9 thoughts on “Tomato Blight: Is Gardening a Green Science … ?

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  1. Exactly the same here when I was growing them outside. If there is an attack, I cut the sick stems and burn them or take them to the recycling center. I don’t change the compost or the soil.
    On the other hand those which are grown outside, I put a roof to them above, so that they don’t catch rain or humidity. I never water the foliage.
    And now I grow them in the greenhouse with the same conditions without wetting the leaves and automatic drip system morning and evening. No disease for six years


  2. I am trying a recommendation from MIgardner on youtube. I started seeing the start of blight, so I cut away the worst affected leaves. cleaned cutters after to not spread the blight. Then sprayed with 1 gallon water, 2 Tablespoon baking soda, 1 Tablespoon vegetable oil, a few drops dish soap. he says to use once week to treat, once every 2 weeks to prevent. He also says to prune away all the lower branches for good air circulation. For containers I would empty then and wash the containers with bleach and water. I would probably change the soil, if that isn’t possible, I would put it on plastic , spray with the above solution and dry in the hot sun for many days.

    Liked by 1 person

    1. Deely, the baking soda, veg oil and dish soap sounds an interesting combination. I’d love to follow your progess to see how you get on. I won’t plant any more tomatoes this season. I am undecided about the soil. It seems such a waste to throw it away.

      Liked by 1 person

  3. Hi,

    We had exactly the same issue at our allotment in the U.K. It was so sad, tons of tomatoes then next door had blight and we didn’t know that he was using our compost bin! It spread so fast and wiped out all our tomatoe plants. You need to throw away all the contaminated soil that are in the pots, your lucky as ours was in the ground and we couldn’t plant anything in that section for a while. DO NOT compost the blighted plants, we bagged up and binned, I know that’s not very environmentally friendly but fires were restricted at our allotment. I am sorry for your loss, I know what it feels like. Here in Portugal our tomatoes are fine (fingers crossed) but we had the rot/fungus which took all but one of my sunflowers.They were all in pots so I sterilised the empty pots in the bath tub and threw away the plants and soil. We have one sole survivor and I like to watch it dancing in the wind (ha ha).

    Liked by 2 people

    1. Hi Helen.
      Thank you for stopping by and taking the time to share your experience.
      After reading your comment, decision made. I am going to dispose of the compost and the plants. Fortunately I only grow the tomatoes in posts … actually, i have one in the raised bed. I think i will remove it before it gets blight and contaminates the soil.

      What a shame about your sunflowers!

      As an aside, have you tried using comfrey as a liquid feed?


  4. I would burn the removed diseased plants. Do not compost. I also would not plant tomatoes potatoes or strawberries in that ground for a few years.
    Research varieties as some are less susceptible to blight. Perhaps try them in growbags for a couple of seasons. Hope that helps

    Liked by 1 person

    1. Thanks, Dorris. The pot with the cherry tomato plant was sold as ‘blight resistant’. Needless to say I felt cheated as the seeds were expensive. 😦 You raise an interesting point about strawberries. I was not aware they were also susceptible to blight. I just researched ‘Phomopsis leaf blight is a common disease of strawberry’. Wow, thanks for the heads-up.

      Liked by 1 person

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