Disease Of Tomatoes

Keys to Growing Healthy Tomatoes

Whether you’re growing tomatoes from your garden or from containers these fruits are delicious and will flavor your favorite salads and recipes giving that WOW. Not only will you be enjoying the flavors these fruits bring but the healthy side which is so beneficial to our health but what can put a damper on reaping a harvest is tomatoes which contract a disease.

All of that hard work will be paid off so don’t despair despite your tomatoes has disease issues you can still reap a harvest by following these methods as you nurse your tomato plants back to good health. Here are diseases to keep an eye on including how to treat them.

Disease of tomatoes-disease-of-tomato
Disease of tomatoes

Disease of Tomatoes

  • Early Blight
  • Dumping Off
  • Late Blight
  • Septoria Leaf Spot
  • Blossom Drop
  • Anthracnose
  • Sunscald
  • Mosaic Virus
  • Tomato Bacterial Diseases
  • Blossom-End Rot
  • Fusarium and Verticillium Wilt

Early Blight

1. Early blight is encouraged by a fungus, the signs of early blight show up as the lower leaves having dark edges with brown to black spots. Black areas that are large and sunken appears at the end of the stem. This disease usually occurs after the plant sets fruits.

Dumping Off

2. Damping-off is caused by a fungal disease that causes seedlings, not to germanate. To avoid damping-off pre-soak tomato seeds which will encourage germination. Planting seeds when the soil temperature is right will also go a long way in the health and proper germination of your tomato seeds. Don’t overwater or have the soil saturated but rather allow the soil to dry out then water thoroughly again. If potting in containers ensure that the containers are sterilized and the potting soil is disease-free.

Late Blight

3. Late blight that is caused by a fungus occurs at the end of the growing season, this disease is encouraged by long periods of cool rainy weather. Signs show up as irregular green to black splotches, the infected fruit will become rotten having large irregular shaped brown splotches. To treat late blight use a fungicide that is formulated for tomatoes to bring under control.

Septoria Leaf Spot

4. Septoria leaf spot is encouraged by long periods of wet warm weather, the symptoms of this disease include yellowing of the leaves followed by leaf drop. Spots that are black may be seen in the center along with a grayish-white with edges turning dark. When watering your tomato plant watering during the early morning hours so that leaves that are wet can dry.

When watering water at the base or the soil level, avoid overhead irrigation, and when installing your tomato plant give enough spacing for proper air flow or circulation. Spores can also be spread to other plants by splashing so be very careful when watering. To treat this disease the use of a fungicide that is formulated for tomatoes will bring this disease under control.

Blossom Drop

5. The temperature plays an important part in the control of this disease when temperatures reach anywhere above 85 degrees F or drop in the mid to low  fifties will affect your tomatoes. The main control of blossom drop is to grow healthy plants that are vibrant.


6. The fungus that encourages anthracnose is most active during weathers that are wet and warm, disease show as indented areas on your tomatoes which are circular and small. Your tomatoes may rot completely to avoid this disease harvest your tomatoes as they are ripe. Rain splash will also cause the spores to spread.


7. Sunscald will cause parts of your tomatoes to become light in color, dry and soft. To avoid sunscald ensure that there is enough foliage on your tomato plant for shade or protect fruits by covering them with a shade cloth.

Mosaic Virus

8. The mosaic virus causes the leaves to turn from a light green to yellowish appearance, the leaves may also be deformed with molting on the tomato fruit. There are also fewer fruit yields which are of poor quality. Planting varieties that are resistant, avoid planting in the seem area that may be infected, avoiding plant injury which can cause the virus to enter from wounds will keep this virus at bay.

Tomato Bacterial Diseases

9. Tomato bacterial disease appears as spots on the fruits and the leaves, be careful when handling plants not to cause injury where the bacteria can enter. The use of a copper spray will offer help, the copper spray should be applied soon as symptoms are detected.

Blossom-End Rot

10. Blossom-end rot signs appear as dark brown and black spots that appear at the blossom end of your tomato fruit. As the disease spreads it gets larger causing the fruit to deteriorate. Watering unevenly contributes to the spread of this disease which causes the fluctuations of available nutrients.

Too much nitrogen along with a lack of calcium during fruit, set is another factor. Provide regular deep watering and removing infected fruit will help your tomato plant to bounce back.

Fusarium and Verticillium Wilt

11. Fungi that are in the soil enter the plant through the young roots, the vessels that are responsible to move water through the stems and roots become plugged.  When this happens the plant will wilt during hot sunny days but will appear to recover at night time, leaf tip dieback will be seen along with causing the top and the lower leaves to lose their color.

This disease is further encouraged by a mixture of cool to warm weathers, to prevent this disease avoid overwatering your plant, plant disease-resistant varieties. Infected plants should be removed and the area should remain clear and not replanted for several years because of the fungi that inhabit the soil. Heirloom varieties which have not been bred to withstand these disease will be infected.

Additional information

A few other tips to avoid plant disease.

1. When using pruners ensure that it’s sterilized to avoid the spread of plant disease.

2. Ensure that containers have drain holes for water to find a way of escape because trapped water will encourage rot.

3. know your plant’s water requirements.

4. Before using fungicides or other products to treat disease read and follow the manufacture’s label.

5. All garden tools should be in good repair.

6. A sharp hand pruner will make and even cut, dull pruners will rip or tear the plant which may also lead to disease.

7. Diseased plant parts should be removed and properly disposed of.

8. Don’t use soils that are diseased.

9. Sterilize container before using.

10. Keeping the plant bed free of weeds and other debris will help greatly. Weeds will not only encourage garden insect pests but can also be the breathing ground for disease.

Sterilizing mixture

A good mixture is bleach and water. Add 3 tablespoons of bleach to half a gallon of water, shake well and you are set to go. When cleaning tools this solution can be sprayed directly onto the tools or apply to a piece of clean cloth and gently wipe the tool’s blade. Be very careful not to cut your hands.

The final word

Growing and harvesting tomatoes are not hard at all, these issues which we have discussed can be controlled by putting the proper methods in place as stated in this post. Don’t let these diseases stop you from reaping a good harvest but fight back with these proven methods as you successfully grow and harvest tomatoes from your home garden.


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About the author

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Norman loves being in the garden, both at home and for his job....
he is 'Natures Little helper' being outdoors, growing his vegetables and flowers from an early age.
Now having spent over 22 years in the profession he want to give some of his knowledge to others...
his vast array of hints and tips you will find scattered over this site will help you no end growing plants in your garden.

2 thoughts on “Disease Of Tomatoes”

  1. Thank god but parasites never influenced my tomato plant. However, I had some problems with peach and appricot tree. It was a real struggle to keep them alive but I’ve managed to do so with organic treatment and small amount of herbicides. Since I also have a tomato tree in my garden for my personal use, I will definitely use your advice on preventing the tomato diseases.


    • It is so good to hear that you are having much success in your garden thanks for sharing that bit of information and I am so happy to help.


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