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Tomato plants have curled leaves and bumps on stems

by Diane
(Laurence Harbor, NJ USA)

Q. Can you tell me what to do to remedy my tomato plant's curling leaves and white bumps on its stem? It has been very hot and dry here and this plant has been watered daily, otherwise it droops and withers. It is planted alone in a large garden pot with good soil and is on an outside deck. It has several tomatoes on it, but I fear they will not make it.

A. You've got three issues going on. At least two of them can be related: bumps on stems and leaf curling.

1. Bumps on stems. The bumps on the stem are likely root initials. They are the earliest stage of development of a tomato’s roots.

Most of the time, bumps are not harmful to tomato plants and are considered normal. Root initials emerge on a tomato stem as a result of stress – most often when there’s a limit or blockage in the stem. Bottom line: the blockage is caused by over-watering, poor drainage, humidity, disease, or root damage.

When root initials make contact the soil, they will grow. Mound compost or top soil around root initials on the lower part of the plant. They will develop into full-blown roots, strengthening the plant’s root system.

Learn more about root initials.

2. Curling leaves
Root initials on your plant's stem combined with curled leaves at the tops and the branch ends can indicate exposure to an herbicide.

Herbicide effects mimic the plant hormone auxin and can also cause abnormal stem growth and leaf distortion.

If your tomato patch is near your yard or a neighbor’s, perhaps a weed-and-feed product, weed control, or other herbicide was applied and drifted. Mist often affects tomato plants.

The good news is that tomato plants can withstand a herbicide injury and often outgrow it when exposure stops. So if you (or a neighbor) have been spraying with Round Up either nearby or when there's a breeze - and stop - the curling should stop soon.

3. The heat and containers
Even though you're watering faithfully, tomatoes can easily get stressed in containers. In hot weather, set folding chairs over plants in midday. Or move containers to the shade during the hottest hours of the day.

Good Luck and Happy Gardening!
Your friends at Tomato Dirt

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Jul 07, 2015
Heirloom tomatoes
by: Anonymous

My tomatoes are heirlooms they have not been near any sprays they are planted in two tires stacked on top have never had any problems with other tomatoes hybrids but the but the heirlooms I bought 7 plants and have problems with several one died grew about 1mo. Grew no more sirriveled up for 2or3wks. Died one is growing one that is suppose to produce big big tomatoes isn't growing much several of the other plants are getting hard yellow welts on the main stems and their leaves are coiling around the leaves are thicker then the of other Tom.plants I have had before the leaves may get something that dirt nag maybe orange area

Aug 01, 2014
Curled leaves and white bumps on stem
by: Ty

You are encountering stem rot caused by bacterial infection.(white bumps along stem).Bacteria enter through injured tissue.Whole plant remaining wet for long periods aid infection.Water at ground level.

Jun 30, 2014
tomato bumps and dying plants

My once healthy tomato plants are dying! I have raised tomato plants for about 60 years and never had this problem.
I have tomatoes in the opposite corners of the garden dying!
No spray around here. I think that there is more to this than tomatoes trying to root along the stem.
The tomatoes have bumps on the main stem 7 inches above the ground and on the off shooting branches as well. The leaves are withering away.

Jul 19, 2011
by: art wilmeth

I live in FL and have the same problem as you describe my 2 plants have produced only 3 tomatoes 2 in dia. They are in early morning sun then shaded the rest of the day. I just started fertilizer but don't see much difference.

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