By Larry Hodgson
Question: What’s causing the yellow or white spots on our tomatoes? Underneath, the flesh is white, spongy and inedible and we have to remove almost half of the tomato to eliminate it. Is there a cure?
Luce Hamel
Answer: Your tomatoes are suffering from cloud spot. This sounds like a disease, but is actually the result of injuries due to piercing insects, usually stink bugs or leaf-footed bugs. There are several species that visit our gardens and cause this kind of damage.
Stink bugs are a foul-smelling, shield-shaped insects that can be, depending on the species and its degree of maturity, brown, green, red or other colors. Leaf-footed bugs, mostly seen in fairly mild climates, are similar, but more elongated with leaflike structures on their legs.
The adult (and in many species, also the nymph) pierces the fruit with its rostrum and injects it with enzymes which liquefy the tomato flesh so it can then suck it out, leaving a wound that turns white or yellow on the outside over time.
Inside the fruit, just under the skin, harder white masses form. They’re not very appetizing and need to be cut out with a knife when preparing the tomato. That wastes a lot of tomato flesh … and time.
You can often control this insect by rinsing the fruits with water daily shortly after they start to form or by hand-picking the bugs and dropping them in a bucket of soapy water where they’ll drown. To make picking them easier, place a cloth under the plant and give it a shake. That usually causes the bugs to drop off and then you can just pick up the cloth and shake it over soapy water.
Some people find they get good results by harvesting the bugs with a hand vacuum cleaner.
This is our first garden in a while. We have a raised bed garden. The only tomato plant that has a problem is the beefsteak. I was amazed by the size when the first one got so big. But when it finally started to ripen it had whitish to yellow spots on it. I was heart broken. What causes this???
The whitish to yellow spots on your beefsteak tomatoes as they ripen could be due to several factors, including sunscald from intense sunlight exposure, calcium deficiency leading to blossom-end rot, pest damage from insects like stink bugs, fungal infections such as early blight or powdery mildew, or nutritional deficiencies. To address these issues, provide shade during the hottest parts of the day, ensure consistent watering and balanced fertilization, add calcium supplements if needed, regularly inspect for pests and use appropriate controls. In future, choose disease resistant tomatoes.
Are they safe to eat? And make sauce with?
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This is good to know. I just replanted some tomato sprouts the other day.
I also have white spots on my tomatoes but they were caused by hail. Some of the tomatoes were too damaged, just a few are salvageable.
Thanks for that explanation! ?
I haven’t had the issue with tomatoes, but the stink bugs are here even sitting on window screens on the second floor. Last year, they hung around all through the winter which was definitely a first. I wish it was the last but apparently not.
Yes, the marmorated ones are becoming quite a pest.