Help, My Tomato Has Wilted!

There’s nothing sadder than a crop gone awry, all that love and care down the tubes. In this case we have a wilted (past the point of recovery) tomato. When something goes awry in the vegie patch look to the obvious things first (I know how you love to declare phytophthora).

1. Has your tomato dried out? Check the soil. (By the way the worst thing you can do when its baking hot and your poor plant has dried out is to pour a heap load of water on it. Lay a slow dribbling hose at it’s feet, and toss some shadecloth over it)
2. Have you over watered? Seems contrary I know, but too much water will make your tomato wilt. Soggy soil drives out the air and creates  the perfect home for soil fungi (more on that later).
3. Changeable weather – cold to suddenly hot and back again (sound familiar?) – makes plants despondent, and I don’t blame them. They wilt in protest, coming right once the weather settles.
4. Has an animal or insect nibbled away at the base of your plant?
5. Spray drift? (surely not!)
6. Have you gone crazy with enthusiasm for artifical fertiliser or manure or manure teas? Pull back!Too much is, well just too much. And you know you don’t need artificial fertilisers – soil has been growing things on its own forever.

If none of these fit then lets explore the possibility of soil fungus. This tomato, it seems, has one of the Wilts – Verticulum Wilt or Fusarium Wilt. (Because I’m a simple girl, lets just call it the Wilts.)

The Wilts declare themselves on a suddenly hot day (chances are you can relate), and usually when the tomato is carrying a lovely load of fruit. The top of the plant or one side of the plant will wilt in the heat. This means the fungus is in. It starts in the roots and makes its way upward, clogging the plumbing and cutting off the water supply – hence the wilting.

Know the Signs

• Wilting at the tips when it’s hot and recovering when it cools off again. This usually starts when the tomato is bearing fruit. Wilting can also happen after watering – especially if your soils are too wet/ heavy.
• Lower leaves grow yellow splotches followed by brown veins followed by brown dead spots. They may fall off.
• Plants lack vigour.
• Fruits are small and don’t ripen properly on the shoulders

Your wilt infected tomato may see the season out, but will produce less/ smaller fruit; or the wilts/ yellowing will progressively get worse until the whole plant collapses.

Prevention and Management

• Crop rotation of at least four years – the Wilts affect all solanacae.
• Because the Wilts thrive in cool, wet soils be sure of well drained garden beds and best watering practice ie let the soil dry out between waterings, and water until moist – not wet.
• Remove plants that collapse, taking as much of the soil as you can bear to part with. Sow a cleansing greencrop of mustard.
• Now that the plant is finished you can do an autopsy to check if your diagnosis was correct. Slice the stem open in the bottom 20cm of the plant. If it is the Wilts, you’ll find brown streaks, or mushy brown bits, could even be smelly as well. Now toss it on the bonfire and toast that fungus.

Two Types of Wilt

There are two types – Verticulum and Fusarium. Both so similar that it’s not really worth delving into, but let’s… just a little. Fusarium is fast and there’s more drama with the yellowing. Verticulum is slow (the plant may last the whole season for you). Fusarium usually shows up on just one side, whereas Verticulum shows on the whole plant.