Tomato Diseases & Problems - The Vegetable Doctor is In!

By on July 14, 2011

The Tomato Doctor is here to diagnose your problems

Just another day in the life of the Vegetable Doctor during tomato season.
sunscald on tomato
A tomato walked into the Vegetable Doctor’s office at 8 a.m. complaining, “Doc, I’ve got leathery patches on my skin. They’re white or light brown. What’s wrong with me?” The Vegetable Doctor said,“You’ve got sunscald from too much sun hitting you. Tell your gardener to make sure there are enough leaves on your plant so you get more shade in the afternoon.”

The second patient was wheeled in by one of the nurses, with a big, grey gash down his side. The nurse shook her head, “Doctor, I think I know what happened here. He was drinking heavily and then every once in awhile he’d go cold turkey and dry out.” The doctor agreed, “Unfortunately this is a classic case of cracking. If this tomato had been drinking at a steady rate he would have been just fine. He should have tried drip irrigation. I’ll give him a prescription for mulch, to keep his soil moisture more even.”
cracking tomatoes
Just before lunch, a tomato wearing a veil opened the door of the doctor’s office and whispered, “Doctor, I’m embarrassed to go to potlucks. When I take off this veil you’ll see how strange my skin looks.” She removed her veil and the Vegetable Doctor nodded. “Just what I was afraid of, you have blotchy ripening. Have you been living in a hot, overcast climate? You needed more sun during the day or more potassium. Here’s a box of balanced fertilizer that should help even out the skintone for the other tomatoes on your plant.”

The first patient after lunch was a tomato the Vegetable Doctor knew well. This tomato tended to read up on his symptoms before he came to the office and was always trying to diagnose himself. “Doctor, I’ve been online watching Tricia’s video on tomato problems , and I’m pretty sure my trouble is caused by overhead watering. See these one-centimeter concentric circles? I think I have early blight. I want you to write me a prescription for Liqui-Cop spray.” The Vegetable Doctor sighed and said, “As usual, you’re absolutely right. We could talk about other fungicides, but Liqui-Cop is a broad-spectrum, copper fungicide and it’s your best bet. Do you want me to call this in to your usual organic gardening supply store?” The tomato nodded. “And”, said the doctor, “tell your gardener to lay off the overhead watering. It sets you up for these problems. Why hasn’t your gardener changed to drip irrigation?” The tomato shrugged.
blossom end rot on tomatoes
As part of his family practice the Vegetable Doctor also saw juvenile patients. A very young tomato toddled into his office, pointing to his blossom end where there were scattered brown spots. The doctor lifted him up on to the examining table and studied him. “Hmm, looks like the early stage of blossom end rot. Did your gardener check the calcium level in the soil before planting?” The young tomato look confused. “I’ll write a note to your gardener, suggesting she watch some videos on soil testing and good practices for planting tomatoes. A lot of gardeners weren’t able to keep the water supply steady and the soil may not have enough calcium, and I’ve been seeing a lot of this.”

The last patient of the day was the most serious one. A tomato leaf walked slowly in, with yellowing obvious on one side. “Come and sit down right away”, said the Vegetable Doctor, “it’s clear to me that you have fusarium wilt. Luckily I have something that can help.” The tomato leaf sat up straighter. “It’s a fungicide with beneficial microbes, called Mycostop. I’m sending you back to the garden with a sample. Tell your gardener to use this as a soil drench and a foliar spray.” The tomato leaf left with a smile on the green part of her leaf.

After a long day at the office the Vegetable Doctor went home and checked his garden. He admired his healthy tomato plants, pruned for good air circulation, and beamed at them all.

  Comments (12)


I would like to know if Actinovate will harm garden worms and bees. Thanks

Posted by Patsy Braden on Jun. 30, 2013 at 10:16:56 AM

Patsy, Actinovate should have no effect on worms and bees. Thanks for asking! Both are so important to an organic garden.

Posted by on Jul. 15, 2013 at 5:10:52 PM


thanks for the interesting article. I have some yellowing on my newly planted one gallon size tomatoes. It doesn’t seem to fit the yellowing curling Fusarium wilt that I read about above. Do you have any other ideas as what could be causing the yellowing? I do use irrigation lines. smile

Posted by Ruth Burton on Jun. 20, 2014 at 5:57:28 PM

Hello Ruth,

Other possible causes of yellowing are a zinc deficiency or nitrogen deficiency. Environmental problems that can cause yellowing are waterlogging, possible a broken emitter? This is a list of tomato problems and pictures and what to do about them from UC Davis:

Posted by on Jun. 24, 2014 at 9:13:25 AM


Hey Doc, I have a white tomato plant that gets flowers but the flowers dry out and fall off before any fruit appears. I have 8 other tomato plants in the gardens and none of them are doing this. these are in raised beds with brand new soil specifically for raised beds. I have sprayed them with calcium spray and still no change. Am I doomed?

Posted by Gloria Nieto on Jul. 10, 2015 at 8:39:18 PM


Let us know what you recommend for spider mites decimating my tomatoes every year?

Posted by Steve on Jul. 11, 2015 at 6:25:00 AM


I’ve had some kind of fungus on my tomatoes this year. The leaves begin by having tiny reddish spots on them, then the turn black, the stems are flimsy and not able to support the tomatoes.  Also should my metal tomato cages be disinfected in some way before I use them again next year?  Thank you.  Great informative article.

Posted by Kandy smith on Jul. 12, 2015 at 3:28:11 AM

Gloria, is your white tomato plant getting adequate water? Usually when flowers dry out and fall off it is a result of some type of stress (water, temperature). Don’t give it excess nitrogen, give it plenty of phosphorus and calcium. I don’t think you are doomed.

Posted by Suzanne at Peaceful Valley on Jul. 14, 2015 at 1:57:10 PM

Steve, I can’t make specific recommendations for pesticides, try looking for those that list to control spider mites, like soaps.

Posted by Suzanne at Peaceful Valley on Jul. 14, 2015 at 1:59:19 PM

Kandy, does sound like a fungus or bacteria on your plants. I would make sure the cages are cleaned thoroughly before next year. You may want to consider solarizing the area you are growing your tomatoes to kill any soil born (bad) organisms.

Posted by Suzanne at Peaceful Valley on Jul. 20, 2015 at 5:23:32 PM


The stems and leaves on the bottom of my tomato plants are dying while the top of the plant is healthy at this point.  My tomato plants are in cages to keep them upright as best as I can.  Can you tell me what is causing this?

Posted by Linda on Jul. 29, 2015 at 1:10:44 PM

This sounds pretty normal. The older leaves typically die off as the plant grows. I wouldn’t worry unless you start getting leaves dying at the top of your plant. Just remove the older dead leaves.

Posted by Suzanne at Peaceful Valley on Aug. 04, 2015 at 10:13:01 AM

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