Have you ever spotted small, round, green fruits on your potato plants that look suspiciously like tomatoes? You’re not alone! Many gardeners are surprised when they find tomato-like growths on their potato plants. But what causes this strange phenomenon? Keep reading to learn why tomatoes sometimes grow on potato plants.
Potatoes and Tomatoes Are Closely Related
Potatoes (Solanum tuberosum) and tomatoes (Solanum lycopersicum) both belong to the nightshade or Solanaceae family of plants This means they share a close genetic relationship and some similar physical characteristics,
Their flowers look very much alike. And while we cultivate them for different edible parts – potatoes for their underground tubers and tomatoes for their fruit – they can occasionally produce structures that resemble one another. So tomato-like fruits on a potato plant may seem impossible but actually makes some biological sense when you consider their family ties!
What Do Potato Fruits Look Like?
The green tomato-resembling growths on potatoes are more accurately described as berry-like fruits. They are small and round or oval, resembling tiny green cherry tomatoes. Their size ranges from that of a pea to a cherry tomato. Some potato varieties may produce fruits with purple-hued skin rather than green.
These fruits contain small, edible seeds and develop after the potato plant flowers. For fruiting to occur, the flowers must be pollinated first. This process is very similar in potatoes and tomatoes since they share ancestry. It helps explain why their fruits end up looking so alike.
Why Don’t We See Potato Fruits More Often?
If potatoes can produce tomato-like fruits, why don’t we see it more regularly? There are a few key reasons this occurrence is uncommon
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Many potato varieties rarely or never flower and fruit naturally, even under ideal growing conditions. Early and late-maturing types are less likely to bloom and set fruit.
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Some varieties may flower but have male sterile blooms that don’t yield viable pollen. Without a transfer of pollen from a different potato variety, fruits won’t form after flowering.
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Even in varieties where flowers are successfully pollinated, the right environmental conditions are still required for fruit formation. Cool, humid summers that mimic the native Andean mountain climate of wild potatoes promote fruiting. Hot, dry weather inhibits it.
So for the average garden potato, the cues needed to trigger fruit production are rarely met. That’s why tomato-like growths are an infrequent surprise rather than the norm!
What Can You Do With Potato Fruits?
While the tomato doppelgangers that grow on potatoes are interesting, caution is warranted! The fruits themselves are NOT edible. They contain solanine, a toxic glycoalkaloid compound found in all green potato plant parts. Eating the fruits risks poisoning, so it’s safest to leave them be and stick to enjoying the edible tubers underground.
However, the ripe seeds inside the fruits can be used to grow new potato plants:
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Allow fruits to fully ripen on the plant until their color changes and texture softens.
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Remove and dry the seeds from fruits. Store them in a cool, dry place.
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In spring, sow the seeds indoors like tomato seeds and transplant outdoors after frost risk passes.
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Tubers will form on mature plants, producing a novel potato harvest!
Growing potatoes from true seeds introduces new genetic diversity, unlike using tubers which are clones. The tubers that develop will exhibit unique traits – an exciting gardening experiment!
When In Doubt, Avoid Eating Potato Plant Parts
So if you spot some suspicious green “tomatoes” on your potato plants someday, no need to panic! While this occurrence is unusual, it’s simply a quirk stemming from the close relationship between potatoes and tomatoes. The fruits themselves are not for eating, but can be used to grow potato plants from seed. Enjoy this garden oddity, but stick to savoring just the edible tubers from your potatoes.
Small, round, tomato-like fruits on potato plants are the true berries of this versatile nightshade family vegetable. Thanks to the close genetic ties between potatoes and tomatoes, they occasionally produce remarkably similar structures. These potato fruits are inedible and quite rare under typical growing conditions. But they can be used to generate new potato plants and add diversity to future harvests! So if you stumble onto some young green “tomatoes” on your potato plant, take a closer look – they’re an intriguing example of biology more than botany gone wrong.
What fruit is growing on my potato plants?
Gretchen Voyle, – September 12, 2014
Gardeners have been surprised this year to find fruit produced on tops of potato plants. Learn how they are caused and why they are not edible.
Potato fruit. Photo by Gerald Holmes, California Polytechnic State University at San Luis Obispo, Bugwood.org
Many home gardeners have been shocked to see their potato plants do something they have not seen before: produce fruit on the tops of the plants. These gardeners are familiar with planting the seed potatoes or potato pieces and digging potatoes at the end of the season. Some might have even noticed the small, tomato-like blossoms in July or August, but few people have seen the fruit that look like green cherry tomatoes at the top of the plants. Michigan State University Extension hotlines have received many calls this summer about strange fruit where it doesn’t belong.
Potatoes belong to a small family, the Nightshade or Solanaceous family. The other members are tomatoes, peppers and eggplants. Potatoes resemble tomatoes more than the other family members. Potatoes and tomatoes can share diseases, like this year’s large problem with late blight. For potatoes, this is the disease responsible for the Irish potato famine in the 1840s. They can share insect problems like tomato hornworm that will feed on both potatoes and tomatoes with nondiscriminatory delight. Occasionally, you will see ads in garden magazines for a grafted tomato-potato mix up that produces tomatoes on the top and potatoes in the soil. This expensive grafted plant does not produce a great number of either. It is like a two-headed calf; it is unusual and nobody else has one to show off.
This year’s cool July was responsible for the potato fruit seen across Michigan. Potato flowers and fruit are produced because this is how the plants multiply themselves, by seed. Potato flowers look very much like tomato flowers except instead of being yellow, the potato flowers can be white or lavender or pink. It depends on the type of potato as to the flower color. Most years, July and the beginning of August are hot and sometimes dry months. Those cute little flowers fall off the plants and never have the opportunity to go from flower to fruit. The cool weather with adequate rain allowed the flowers to remain, pollinate and grow into small potato fruit. These look suspiciously like small, round or oblong cherry tomatoes.
These potato fruit are not edible. More precisely, they are poisonous. They contain high amounts of solanine that can make the eater very ill. Solanine is also found in potatoes that are dug, left in the sun and the skin turns green. Besides being very bitter, eating plant parts containing solanine can lead to headache, abdominal pain, shock and diarrhea. If little kids are around, the fruit should be removed so the children are not tempted to eat them.
If you saved the ripe seeds inside the potato fruit, you would not get the same kind of potatoes as the parent plant. It would take several years to even grow these to a size that you could harvest. The only people saving and planting potato seeds are growers and breeders who are hoping to produce a new variety of potato.
So marvel at the fruit of your potatoes – this is not going to be a yearly event. It is not an evil omen or bad luck. Your potatoes below the soil will be just fine. Just blame it on the weather.
How I Grew Potatoes And Tomatoes On The Same Plant
FAQ
Why are tomatoes growing on my potatoes?
Re: What are the tomato looking things on my potato plant? They are the fruits of the potato plant. They come after the flowers fall off. Most people remove the flowers, so never get to see the fruit. You can grow potatoes from these, I’ve got 2 in my greenhouse from last year’s potato fruit.
Are potato tomatoes edible?
This is something that has amazed me since the first time I saw it! Potato plants produce flowers and fruit. The fruit looks just like small green tomatoes! They are not edible though. The reason for this is that potatoes are related to tomato plants! They are both from the “Solanaceae” family which also.
What are the things that look like tomatoes on my potato plants?
Potato flowers look very much like tomato flowers except instead of being yellow, the potato flowers can be white or lavender or pink.Sep 12, 2014
Can potatoes and tomatoes hybridize?
Now it’s a reality: You can buy a “TomTato” plant from British seed company Thompson & Morgan … and a “Potato Tom” from New Zealand’s Incredible Edibles nursery. Instead of using genetic modification, the two companies created hybrid plants by grafting, or physically attaching, two separate plants to one another.
Can you plant Tomatoes next to potatoes?
It seems logical that you could plant tomato plants next to potatoes since they are in the same family. It is okay to plant tomatoes near potatoes. The operative word here is “near.” Since both tomatoes and potatoes are in the same family, they are also susceptible to some of the same diseases.
Can tomatoes and potatoes grow on the same plant?
Yes, tomatoes and potatoes can grow on the same plant when grafted together. The result is a unique plant that produces tomatoes above ground and potatoes below ground. Why do you graft tomatoes to potatoes? Grafting tomatoes to potatoes offers several benefits:
How do you grow a tomato & a potato?
TomTatoes should be grown in full sun in well-draining, rich, fertile soil with plenty of organic matter. The soil pH should be between 5 and 6. Tomatoes and potatoes both need plenty of food, so be sure to fertilize at planting and again in three months. Water the plant consistently and deeply and protect it from strong winds or frost.
Can Tomatoes be grafted to potatoes?
Grafting tomatoes to potatoes offers several benefits: The combined plant requires less space than two separate plants, making it ideal for small gardens or urban settings. The grafted plant uses water and nutrients more efficiently than two separate plants, reducing resource consumption.
Can you grow pomatoes and tomatoes together?
If you love tomatoes and potatoes, you should consider growing pomatoes. This is a garden vegetable created by grafting the potato plant’s roots onto the stem of a tomato plant.
How far should a tomato plant be from a potato?
A good 10 feet (3 m.) between tomatoes and potatoes is the rule of thumb. Also, practice crop rotation to ensure healthy crops when growing tomato plants next to potatoes. Crop rotation should be a standard practice for all gardeners to prevent cross-contamination and the spread of diseases.