How to Identify Tomato Problems and Prevent Them

Since 2010, Tomato Dirt has garnered 4.6+ million views, making it the web’s leading online source for growing tomatoes in the home garden. Award-winning writer and Tomato Dirt owner Kathy Widenhouse has helped thousands of home gardeners grow healthier tomatoes. Be one of them when you get Tomato Dirt’s Growing Guide here.

tomato bush

Even the most diligent gardener can’t control tomato problems in the garden! While healthy tomato plants don’t always start, stay, or end that way, problems needn’t be a death sentence for plants. Most can be halted or reversed.

There are 3 sources of tomato problems:

  1. Tomato diseases
  2. Tomato pests
  3. Growing conditions

How to identify tomato problems

Healthy tomato plants have:

  • green and evenly-colored leaves
  • strong, green stems
  • firm fruit with a smooth color

If you check plants each day, you’ll discover and identify problems at their onset. Then you treat them quickly and successfully. You simply need to know what to look for.

Use this checklist to monitor problems on three tomato parts: leaves, stems, and fruit.

Problems on leaves

  • dark, gray, or white spots
  • yellowed or mottled foliage
  • curled leaves
  • holes
  • stripped foliage
  • sticky dew
Problems on Tomato Leaves: How to Identify, Treat, and Prevent Them

Problems on stems

  • mushiness
  • dark, gray, or discolored streaks
  • holes
  • sticky dew
  • white mold
  • stunted growth
Problems on Tomato Stems: How to Identify, Treat, and Prevent Them

Problems on fruit

  • sunken or discolored spots
  • misshapen fruit
  • cracks
  • holes
Problems on Tomato Fruit: How to Identify Them, What to Do

How to prevent problems

Take steps before, during, and after the growing season to prevent problems from creeping into your tomato crop.

Before the season

  • Rotate your tomato crop from year to year. Many fungi over-winter in the soil. You can prevent infection in a new season by planting tomatoes in a different place than in the previous year.
  • Choose disease-resistant tomato varieties. A variety may have been bred to be resistant to one or more diseases. Look for tomato disease-resistant codes on seed or seedling packets, specified by capital letters:

    V=Verticillium Wilt
    F=Fusarium Wilt
    N=nematodes
    A=Alternaria
    T=Tobacco Mosaic Virus
    St=Stemphylium (Gray Leaf Spot
    TSWV=Tomato Spotted Wilt Virus

  • Plant healthy seedlings. Grow your own tomato seeds, or buy tomato plants that are pest- and disease-free.
  • Plant “good neighbors” – companion plants that repel pests and dispel disease

During the season

  • Maintain a consistent watering schedule. Monitor rainfall and supplementing appropriately to provide 1-3 inches a week
  • Water at the soil line. Avoid overhead watering, which can spread disease.
  • Don’t over-water
  • Mulch plants once they’re established – about 3- 5 weeks after setting them out in the garden
  • Don’t let anyone smoke in the garden (tobacco refuse can spread tobacco mosaic virus)

After the season

  • Clear tomato plant debris
  • Destroy infected plants

Have a Tomato Problem or Question?

You can ask questions and find answers about ...

Problems on tomato leaves

Problems on tomato stems

Problems on tomato fruit

But if you have another problem with your tomatoes, a question about tomato care, or a great tip about handling tomato diseases and pests, you can share it here.

[ ? ]

Upload 1-4 Pictures or Graphics (optional)[ ? ]

 

Click here to upload more images (optional)

Author Information (optional)

To receive credit as the author, enter your information below.

(first or full name)

(e.g., City, State, Country)

Submit Your Contribution

  •  submission guidelines.


(You can preview and edit on the next page)

What Other Visitors Have Said

Click below to see contributions from other visitors to this page...

Tiny white flying pests on tomatoes 
Q. I have tiny white flying insects attacking my tomatoes. They appear mostly on the underside of the leaves, and leave tiny little discolorations where …

Can I grow tomatoes in clay soil? 
Q. Can I grow tomatoes in clay soil? A. The short answer is yes. Here are a couple of ways you can do so. One hole at a time. While other garden …

Is it normal for a tomato to have bright white seeds inside? 
Q. I've lived many years and eaten many tomatoes but have never had one that was predominantly white inside - seeds, flesh, etc. Is this normal? A. …

Tomato thieves 
Q. Is there anyway to keep squirrels and other wildlife from grabbing my tomatoes, taking a bite and running away? I have covered them with netting (fastened …

Why are the flowers on my tomato plants dying off before developing? 
Q. I'm a newbie tomato grower (this year's my first attempt). I live in Cancun, so we've got average daytime temps of around 30 C (8 6F) and high humidity. …

Lots of green leaves, no blossoms 
Q. I have large, green, healthy tomato plants with no blossoms. Why? A. An abundance of tomato foliage with few or no blossoms is most often attributed …

Blight spray on tomato fruit 
Q. I am wondering: does the spray used against blight for tomatoes have a waiting time period after which fruit must not be eaten? Fungicide products say …

How can we get tomatoes on our plants instead of all leaves? 
Q. We have planted our tomatoes and now we are getting big leafy plants and very few tomatoes. The crotch shoots have been removed and the plants are a …

Sparse foliage and color too light 
Q. The foliage on my tomatoes seems sparse and the color too light. But each plant has lots of blooms and several tomatoes. What might be the problem? …

How can I get rid of funguses in the soil? 
Q. I have 2 tomato plants from last year that I saved. They where doing well, but we had a wet winter. The water drained away from the base of the tomatoes. …

Can tomato blight be spread by tillers and tomato cages? 
Q. Can tomato blight be spread to a new garden by tiller or tomato cages that came into contact with blight the year before? We are starting a new tomato …

Tumbling Tom Tomatoes Aren't Tumbling 
Q. I potted up 6 hanging baskets with tumbling toms, 3 red and 3 yellow. They look great and are about 22 inches tall, They are not tumbling over but growing …

Growing tomatoes under shade cloth 
Q. I have raised Juliet tomatoes for several years with very little problems and consistent taste from start to finish except for the past 2 years. We …

Went away for 3 days and now my tomato plants are yellowing! 
My tomato plants are in a small plot, which is a turned-up old flower bed that's been covered in black tarp and landscaping stones for several years. When …

Tomato leaves are curling 
Q. I have just noticed that my tomato leaves are curling. The flowers are starting to dry up but I do not see any spots. I was told is early blight. Should …

Tomato Blossoms Not rated yet
Q. Our tomatoes didn't have much luck this year. Blossoms fall apart before they set fruit. I heard that when flowers bloom, we should cut back the water …

Question about fertilizer... Not rated yet
Q. I have heard that Epsom salts can be used for fertilizer. Do you agree and would you recommend it as a natural fertilizer? Tomato Dirt responds …

What type of container for growing tomatoes? Not rated yet
Q. What type of container is best for growing tomatoes on a deck? We have both clay pots and plastic ... is one preferred over the other? A. Both …

Growing Tomatoes Inside During Winter Not rated yet
Q. Can I grow a couple plants in my shop this winter with grow lights? If so, let me know any tips for first time effort. A. There are three places …

Many blooms, little fruit Not rated yet
Q. I have 8 plants grown from seeds, now in pots of varying sizes. Stems strong; leaves green, blooms a many for last 4 weeks. However, the blooms do …

Clay soil; not many leaves, blossoms, or fruit on tomato plants Not rated yet
Q. I planted my tomatoes sometime ago. I have 12 plants. Three are growing and have leaves and blossoms. I had little green tomatoes almost as soon as …

Tomato Plant Suckers Not rated yet
Q. Should I prune all the suckers from my tomato plants? A. Pruning tomato plants can maximize the number, size, and flavor of your tomatoes. So some …

Why are tomato plants are dying? Not rated yet
Q. Our tomato plants have light brownish, grayish leaves. They are sick and dying! Can you help? A. There are at least 3 possible diseases that …

Lack of Tomato Production  Not rated yet
Q. My plants have only produced 3 tomatoes. They have been growing in a 5 gallon bucket. I drilled two 2" holes in the side. The plants are growing …

Click here to write your own.

Blossoms falling off, blackened Not rated yet
Q. I just planted my tomatoes, so this is a preventative question. Last year I had a problem with blossoms turning black on the stem right beneath the …

Worried about the Oregon wet cold spring Not rated yet
Q. I just transplanted my starter tomatoes to my patch garden at work. I started them from seeds. Great seeds - all came up. Now, I'm worried. I …

Hanging tomato shriveled and died  Not rated yet
Last year, in late May/June, I planted tomatoes in a 5 gallon bucket with holes in the side, like a hanging plant. I kept them watered, but they died. …

Poor Root Development Not rated yet
When I pulled my tomato plants this fall, I was surprised to find that the plants have very little root development. Some had only a six-inch diameter …

Click here to write your own.

Return from Tomato Problems to Tomato Dirt home

As an Amazon Associate and Rakuten Advertising affiliate I earn from qualifying purchases.

New! Comments

Have your say about what you just read! Leave a comment in the box below.

SHARE THIS PAGE:

 

FREE! 10 Must-Know Tomato Growing Tips: 20-page guide
Get yours here: