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Problems With Tomato Plants

Here is my list of problems with tomato plants, what causes it and what to do about it. With

Cherry Tomatoes
Cherry Tomatoes

any luck we’ll have your tomato growing problems solved in no time. Don’t be scared off lists like this often make me feel that it is a miracle if I get one good tomato. I’ve never had many of these problems if you rotate your crop and keep the water regular you should be fine – just have a go. If you have a problem that I haven’t covered just leave me a question in the comments and I’ll try to solve it for you. Remember that tomatoes like most vegetables are actually an annual crop so they will grow like crazy put all their energy into producing fruit then die. So the plant will often look pretty shabby toward the end of the harvest. 

Lots of beautiful lush green growth but no fruit
Have you been feeding your tomato plants with a nitrogen rich fertilizer? Tomatoes do need fertilizer but nitrogen encourages lots of foliage to grow. Phosphorus on the other hand encourages flowers and fruit. Check out the numbers on the fertilizer  pack. There are three N P & K. Nitrogen is the first one the P is for phosphorus and K which is for potassium. Try to choose one that has the second number higher than the first for any plants that get flowers. Make sure you follow the direction it’s easy to apply too much especially if growing in containers.  I have used this one in the past with great success. You can use it on all your vegetables and it also has added calcium which will help to avoid my next problem which is blossom end rot. There is also this one from Burpees that I have read some great reviews about sadly I can’t get it where I live.
There is a soft rotten spot on the bottom of the fruit tomato_blossom_end_rot

This is probably Blossom end rot and is caused by a calcium deficiency. This can be caused by irregular watering  – too much then not enough. The plant just can’t suck up the calcium it needs. You can test the soil for a calcium deficiency if you like but I’d just make sure I use a fertilizer that has added calcium and see if that helps. It is still OK to eat the fruit if it’s not too bad you can just cut off the yucky bit.

This image is from the Center Of Agriculture Food and environment – University of Massachusetts

The flowers fall of before it gets fruit

This is usually caused by the weather being too cool for the plant – this problem will solve itself once the weather warms up. Tomatoes are best in hot dry climates. The leaves may also curl if it’s too cool. This can also happen if it gets too hot. If it continues choose a different variety they may suit your conditions better.

The tomatoes split like as if they are too fat for their skin- like an overfilled balloon

This will happen if there is an irregular supply of water. I’ve had this happen when we get a lot of rain all at once there is not much you can do about it when Mother Nature lets go but if the watering is up to you just keep the water regular. While you don’t want the palnt to dry out it’s better to do regular deep watering every few days rather than a little bit more often so that it soaks deep into the soil and therefore to where the roots are. It is still OK to eat split tomatoes.

Tomatoes won’t ripenGreen Tomatoes

This happened to me a few years ago it almost drove me crazy. Lots of big fat perfectly formed green tomatoes. This is what I found out. Tomatoes usually grow to there full size in about 25 days then they take about another 25 days to ripen. But all this will only happen if the conditions are perfect. The strangest thing I discovered is that if it gets too warm they don’t go red. If the air temperature goes above 85 degrees they apparently stop making carotene which is what they need to go red. Also if the soil isn’t warm enough that mucks it all up as well – below 80 degrees. We had a really hot summer and so this all explained it perfectly but it is all still weird. I have read that removing some of the fruit  may help to ripen the others but generally I think it’s best to just be patient Mother Nature will figure it out in her own time.

The tomatoes are weird shapes

Many tomatoes that have the best flavor are weird shapes. They are usually the more old fashioned varieties. If it has a big scar on it it it may mean that the nights have been too cold while the fruit was forming I read that they call this a “catface”. Cold weather at pollination time could also cause misshapen fruit. It is OK to eat misshapen fruit.

Wilting or yellow leaves

Could be a fungal disease.  The most serious is verticillium wilt and fusarium wilt and wilting caused by nematodes which attack the root system. Cut through through a major stem and see if the find the inside is discolored and not green like the rest of the plant.These diseases all come from the soil.

If you get any of these  sorry but you will need to dig out the plants and start again. Don’t put them in the compost heap and don’t shake the soil off. You really need to put some effort into prevention by interrupting the life cycle of the disease or pest.

  • Make sure you rotate your crops never planting your tomatoes or peppers in the same soil two years in a row. Never in the same spot more than once in three years.
  • Water the soil not the leaves of the plants as the diseases travel via moisture.
  • Mulch your plants so that the leaves don’t come into contact with the soil.
  • Don’t reuse potting mix that has had diseased plants in it.
  • Plant marigolds to deter nematodes.
  • Sow mustard seeds in the effected area.
  • Keep your soil moist not wet.
  • Choose varieties that are disease resistant – look for a code “VF” on seed packs.
  • I’ve found that mulching my plants and avoiding overhead watering has really helped.
My leaves have spots

Do they move? May be spider mites or aphids. A good spray from the hose will often shoo them away. I usually just wipe them away with my fingers  (I put my gloves on) as I try to avoid water on my tomato leaves it seems to work for me. If you have lots of bugs try an insecticidal soap. Non moving spots could be a fungus. To deter fungus problems, avoid keeping your plants really wet try staking plants so they get good air circulation. There are lots of different things that cause spots on tomatoes my advice is to pick a few leaves and take it to the local garden center or ask a grower at the farmers markets as it seems spots are a bit regional in there appearance.

Spots on the stems

Spots or patches near the joints of the stems could be firsts signs of late blight which spreads from potatoes, often after a wet spell. Dispose of the infected plant before the disease spreads – not in the compost heap.

I’ve got light patches on the fruit

Have you cut some of the leaves off and exposed the fruit to the sun – could be sun burn You need to make sure you don’t take the shade away when you prune. If they a little round patches it could be stink bugs. This could also be caused by a lack of potash in the soil. try adding sulfate of potash to the soil if the other reasons don’t seem to apply. This will also increase the strength of the plant and promote early flowering. If you are using a low nitrogen fertilizer as mentioned in the too many leave no fruit point above you shouldn’t need extra potash.

It is OK to eat the undamaged parts of the tomato.

I have what looks like tiny bites out of the leaves or holes in the fruit

Look for something that chews like a grub or a caterpillar they will probably be the same color as the plant. I usually find that it is easier to look for signs of poo then look where it may have dropped from. I don’t care what the name of these things are if they chew or burrow into my plants they have to go. I usually pick them off with my fingers and I encourage wasps which seem to eat the eggs. Also make sure you check under the leaves for eggs that are waiting to hatch. Perfect solution no chemicals. 

There are bites out of the fruit

Squirrels possums or birds are hungry too. Depending where you live you may have other critters that want their share. Interesting from my experience they all seem to know exactly the day before I’m going to pick them and they take one a bite out of everything.  You can’t eat them then as the critters may have some exotic disease. One solution is a physical barrier to stop them getting to the fruit.  I hate the idea of enclosing my garden it’s a pain every time you want to do something so what I do is pick the tomatoes when they show the first sign of pinking up and put them on the other a table on the other side of the yard amazingly they haven’t found them yet. This method also seems to stop grubs getting into the fruit

Flowers but no fruit

Are there any bees? Most of the time tomatoes don’t have problems with pollination but if it is really still(as in no breeze) or there are no bees you may get reduced fruit. Just give the plant a bit of a shake the pollen from one flower will drop onto the others thus pollinating the flowers should work.


  1. DoruDoru

    Hi Vicki!
    Wow, a lot of useful stuff you got here. My daughter has his own little “farm” and she’s growing potatoes and beans 🙂 I will tell her what I had been reading here because I’m sure she will appreciate.
    Great article and thorough information. Thanks!

    • Thank Doru I hope you found it helpful. Keep your eye out for the vegetarian lady beetle on her potato plants they are a bit bigger than the usual lady beetle and a mustard color they managed to totally eat the green tops on my first potato crop and once they got hold everything in sight. Home grown potatoes make the best fries I’ve ever had.

  2. HelenHelen

    Vicki, I too have had the ‘won’t’ turn red scenario a few times. If it gets towards the end of the best time for ‘reddening’ I have found there are many really good recipes for green tomatoes. I do have a book on this but it’s packed away somewhere! However there will be lots on the net. So you have your usual pickles, chutneys and relishes but there are also ones like green tomatoe marmalade.

  3. SamSam

    very useful and informative post Vicki, just wondering if the points discussed above applies to growing tomatoes indoor or not?

    • Anything that happens to a tomato outside can happen inside as well if the conditions are right or wrong. You might have fewer problems with bugs and you can control the temperature and humidity so should be quite successful. You may have trouble getting fruit to form as you need bees and other insects to pollinate the flowers. Nothing a small paint brush or even a good shake now and them can’t fix.

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