Problem #1
The fruit splits
Splitting, a common issue, generally accurs after a big rainfall. The plant starts taking up water, causing the fruit to swell with moisture, until its skin cannot stretch anymore. The only way to avoid the problem is to tent off the entire plant and the soil around it when it rains. Because this is impractical, it’s best to do nothing. As the soil moisture wanes, the plant will stop taking in so much water and the fruit will stop splitting. If the issue is occurring with a potted tomato plant however, you may be watering too much. Remember that when a tomato plant starts producing fruit, it only needs about 1 inch of water per week.
Even watering is best.
Problem #2
There are greasy brown patches all over your plants
UH OH – if you see these marks you’ve got blight. If this is happening in the spring, then your plants have an early blight; if it’s happening after they have already begun to set fruit, then it is likely late blight. Either way, there’s not much you can do to salvage the crop. The disease will eventually kill the plant. Remove any plant that has been infected, dispose of it, (not in the compost pile) and hope that the disease doesn’t spread to the rest of the tomatoes. Blight is caused by an oomycete pathogen. This organism infects a plant, causing it to develop a fungus, which in turn produces millions of fungal spores that travel in the air, land on other plants, and if the weather is sufficiently wet, cause new infections. Overly moist conditions allow the spores to spread faster. Blight can only survive on living tissue, so tomatoes will not carry blight over winter because freezing kills the whole plant. Tomato seed, even from fruit that was infected with late blight, will not carry the pathogen. So you can use saved seed next year without the fear of blight.
Problem #3
All your ripe tomatoes are watery and tasteless.
Nothing is more frustrating than finally harvesting a bunch of seemingly perfect tomatoes from the vine only to find out that they have no taste. Watery, tasteless fruit is due to overwatering. When a plant starts fruiting, it starts looking yellow and tired. That’s when we often rush out to water the plant to perk it up. This is the wrong thing to do. In the simplest of terms, all of that water ends up in your fruit, compromising its flavor and texture. When your plants start looking haggard late in the season, leave them alone. They are supposed to look that way because they are busy putting all their energy into producing delicious fruit.
Problem #4
Chew holes are showing up and ruining the fruit.
Holes could be attributable to several different pests. Large bites are likely from chipmunks or squirrels. But smaller divots are usually due to slugs. One option is to wrap a strip of copper tape around the base of your plant to prevent the slugs’ slimy nocturnal climbs. If this doesn’t work, use slug baits or traps, which are available at most garden centers. Slugs also like to hang out in damp wood chips or leaf mold, so if that is your mulch of choice, switch to straw instead; the sharp crisp texture of the straw deters slugs more than any other mulch.
Problem #5
There are black spots on the bottom of the fruit.
If you see black spots at the bottom of your tomatoes, blossom end rot is the likely culprit. This condition is caused by a calcium imbalance within the plant. Several factors can limit a plant’s ability to absorb enough calcium, including fluctuations in soil moisture (too wet or too dry), an excess of nitrogen in the soil, a soil PH that’s either too high or too low, cold soil, and soil high in salts. In most cases, if you haven’t noticed an issue with other garden plants that would indicate a soil problem, watering is the issue. It is critical to maintain consistent levels of soil moisture throughout the growing season to avoid blossom end rot. There are also products on the market that claim to “stop the rot”, but the reviews are mixed – at best- so buyers beware.
Problem #6
The skin has burned spots
“Burning” is the perfect word to describe this ailment because that is exactly what’s wrong: sunscald. This happens when the delicate skin of the fruit is exposed to large doses of harsh full sun. This problem is a common occurrence in southern locations but can also happen in cooler zones. If you prune out a lot of foliage from your tomato plants (to promote air circulation), you reduce the amount of leaf coverage that will protect the fruit from sunburn. To avoid the situation altogether, plant a thick-skinned variety such as ‘Roma’, and prune judiciously. To rectify a current situation, provide your plants with some shade cover, if possible.
This information was provided by Danielle Sherry, a senior editor for Fine Gardening magazine and was published in the June 2013 issue. To watch a video about troubleshooting tomatoes, go to