Diagnosing Tomato Troubles

Diagnosing Tomato Trouble

Tomato Pests and Disease

Imagine my disappointment the other day went I went out to my garden to check my transplants and found that a cutworm had attacked my Green Zebra and Principe Borghese tomato plants. Grrr.

I planted them from seeds, tended them, and watched them grow into my beautiful healthy seedlings that I put in my garden. Unfortunately sometimes there is just nothing we can do to win the battle against Mother Nature. But, on the plus side there are a whole lot of things we can do to tip the scales in our favor. One of the best ways is to take preventative measures.

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Prevention is the best way to keep from having problems at all. The cleaner and happier you keep your area, the less problems you should have.

  • The first line of defense is don’t over crowd. Plant your tomato seedlings no closer than recommend. Make sure there is plenty of good air circulation. Don’t plant right up next to a solid fence or other obstacle.
  • Make sure to supply a support in the form of a cage or a stake when planting your seedlings. I like to use cages as I feel they give them better support. We wrap the bottom 12″ of the cages with clingy wrap to protect the tomato seedlings from strong Spring winds.
    • Keep the area free of dead leaves and over ripe vegetables. These are just an invitation to disease and pests. Also, be sure to keep the garden well weeded. Weeds tend to fight for the nutrients and water.
    • Do not over water. Do not get water on the leaves. The best way to water is with drip irrigation or a soaker hose. Test the soil by putting your finger down in about 2″. If it is dry – If the ground is still wet at 1″ down wait to water when it is drier.
    • Don’t over prune. As you will see later, this can lead to other problems. Honestly, I do not remove my suckers or prune my tomatoes at all. This is the way I have been gardening for 20 plus years.
    • Make sure your soil is warm enough and at the correct pH of 6.0 to 6.8 before planting.

  • Oh no, I have a problem!

    If you monitor your plants regularly you should be able to see and treat your problem quickly. Here are a few of the problems you may find

    • Blossom end rot – This will show up as a dark , rotted spot on the bottom of your tomato. This could be a Calcium deficiency, or could be due to irregular watering. A lot of times this will go ahead and correct itself as the season progresses. It is safe to cut off the affected part and eat the rest of the tomato.
    • Blossom drop – Your blossoms will not fertilize and they will drop. No fruit is produced. This can happen when temperatures are too high or too low. Not much can be done about this except waiting it out. Be sure though that you buy varieties that are suited for your climate. For example, if you are in a hot climate, buy tomatoes that are heat resistant.
    • Fruit cracking – This can occur when there are heavy rains or hot dry weather. Again, you may just have to wait this one out. The fruit is safe to eat.
    • Sunscald – This is like your tomato getting a sunburn. You will see white areas on the skin. The taste will probably be off. This is caused by the plant canopy not providing enough protection. If you over prune this is an issue. You can or cannot remove the suckers on tomato plants. These are found between the main stem and branches. They produce no fruit, so some argue that they take away nutrients from the “good” producing parts of the plant. Just be careful not to get carried away.
    • Leaf roll – You may encounter this if you have excessively wet soil, or soil that does not have proper drainage. The leaves will curl up towards the center. Monitor your soil conditions and cut back off on watering until the ground is dry 2″ down.
    • Leaf spot – This does not affect the tomatoes, only the leaves. Be sure to water your plants at ground level and do not splash water on the leaves. Make sure you have good air circulation.
    • Early blight – This is caused by a fungus in the soil. To avoid be sure to practice good crop rotation. It starts as small dark spots on the leaves. They will eventually yellow and turn brown. You may have a problem with sunscald if too many of the leaves die.

    Bugs That Love Your Tomatoes as Much as You Do

    Of course there are always bugs that may come into play. Again, regular inspection should lead you to find these before they are an epidemic.

      • Tomato Hornworms – You will know when these bad boys are around. I use white on black plastic garden mulch in my garden. I never have any problem spotting the “calling card” (droppings) from the hornworms. Plus, it is easy to spot the large holes in the tomato leaves. These pests can be hard to spot as they are pretty much the same color as the tomato leaves. But, they are a big caterpillar size, so it is hard for them to hide too much. Best way to get rid of these it to pluck them and squash them. Unfortunately, they turn into the intriguing sphinx, hawk or hummingbird moth. I had one in my garden one year and I just had to run in and search for what it was. They are pretty.

    • Cutworms – These guys like to get after your seedlings. They will come out at night (convenient for not being spotted) and “cut” the seedling off just above ground level. As I said earlier, I had this happen to 2 of my plants this year. Fortunately there was enough still there that they grew back on their own. They are a little behind the other plants at this point, but not really all that significant of an amount. You can make a paper collar to prevent these worms from getting to your tomato plants. Or, you can take a paper cup and cut out the bottom and put it over your seedling for protection.
    • Whiteflies – These are found feeding on the bottom of the tomato leaves. They are small, moth like in appearance and white in color. Your tomato will experience stunted growth, leaf yellowing and reduced yields. You can use neem oil or natural predators such as the ladybug to control these.
    Juicy Tasty Tomatoes

    Juicy Tasty Tomatoes


    Experiment with different varieties to find the best tomato suited for your weather conditions. You may also ask local gardeners or your local extension office which varieties you should try. Don’t get discouraged. In gardening you will win some and lose some. Fortunately for gardeners the wins always outweigh the losses. And the end result, that juicy ripe¬† tomato, is worth the effort. Leave a comment below letting us know any problems you have had and the best solution you have found. Thanks!