Curled Tomato Leaves & Herbicide Damage

by Corinne Mossati

Curled tomato leaves are a sure sign that the plant is under stress. Is the cause poisoning by herbicide drift, environmental factors or a disease? Here’s my story.

Curled Tomato Leaves

Curled Tomato Leaves – Photo © The Gourmantic Garden

Gardening isn’t all pretty pictures of perfect produce, or how many likes we collect on social media. It’s about day to day gardening and how we deal with gardening problems that are beyond our control.⁠

This summer season, all my tomato seedlings that I’ve raised from seed started strong. After transplant – be it in the ground, containers of various sizes, raised garden bed, and in various locations around the garden – they developed feathery leaves, downward leaf curl and stunted growth. ⁠

With the exception of Brad’s Atomic Grape Tomato which seemed to be hanging in there and producing fruit, I removed the first batch in December and replaced them in early January with healthy seedlings I’ve been raising including three seedlings I bought from a garden centre. All have since developed the same problem.

Some Background

Curled Tomato Leaves

Curled Tomato Leaves – Photo © The Gourmantic Garden

Sydney has been under the influence of La Niña which resulted in cooler daytime temperatures and a wetter spring and summer.

The seedlings were started in 10cm pots with quality potting mix (red Australian Standards tick) topped with a thin layer of seed raising mix. At the time of transplant, they were very healthy with a good root system. Those that were transplanted into containers had the same potting mix.

It is worth nothing that this has only affected my tomato plants. The rest of the garden is thriving.⁠

Herbicide Damage

Herbicide Damage – Photo © The Gourmantic Garden

⁠I posted instagram stories asking for advice which I’ve saved under the ‘Pests’ highlight. Many have asked me to share the responses so I have also shared part of this article in an instagram post.

Here are possible causes I was given as well as what can be done.

Possible Causes of Curled Tomato Leaves

  • Herbicide Drift (Neighbours or Council Spraying Nearby⁠)
  • Herbicide Damage (Contaminated Soil, Compost, Manure or Mulch⁠)
  • Environmental Stress
  • Broad Mite Infestation
  • Tomato Yellow Leaf Curl Virus ⁠
  • Tomato/Tobacco Mosaic Virus⁠
  • Blight⁠
  • A combination of the above⁠

In short, nothing conclusive but I’m leaning towards a cocktail of herbicide damage, broad mites and a virus coupled with environmental stress.

Curled Tomato Leaves

Curled Tomato Leaves – Photo © The Gourmantic Garden

Herbicide damage causes leaves to curl downwards. They have a twisted, feathery and curled appearance. The plant may have yellow leaves, split stems and can produce distorted fruit that should not be consumed. Environmental stress can cause leaves to cup inwards giving them a leathery appearance and it can also manifest as nodules or lumps on the leaves. Broad mite infestation signs include curling and wilting leaves, stunted growth and a bronze/rust colour on the underside of the leaves and fruit.

What I’ve Done

Blistered Appearance

Blistered Appearance on Tomato Leaves – Photo © The Gourmantic Garden

I have used new bags of soil/compost/mulch, watered well to dilute the herbicide (a wet summer has helped a lot), sprayed with wettable sulfur and nothing has made a difference. ⁠

I have declared tomato season to be over for me this year. I’m keeping some plants for now to observe progress . Others will be binned (not in the green bin) and I won’t be sowing any tomato seeds again until March as La Niña is ⁠likely to remain until early autumn.

If there are any further developments, I will update this article as I hope this information will help someone in the future.⁠

Want to Know More?

You’ll find more information on how to grow tomatoes, which varieties to try, how to pair it with food and spirits, and how to use tomatoes in cocktails including a full recipe in my 260+ page digital book GROW YOUR OWN COCKTAIL GARDEN available now.


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