Potato fruit

This post is Part 2 of 6 in Stories: Small wonders, little mysteries

Potato fruit on Chieftain variety

Here’s something I haven’t seen before in my, uh, six years of growing potatoes: green, tomato-like, walnut-sized potato fruit. Bob hadn’t seen ’em either, in 40 plus years of farming. I hit the web for education.

These are genuine fruit, but not that common. Usually, potato flowers just drop off. When fruit do form, they’re more likely found on certain varieties, like Yukon Gold. This year, there were fruit on just about every Chieftain plant, here and there on the Kennebec, and none that I noticed on the Yukon Gold…

Each fruit contains 300-500 seeds that don’t come true: planting them doesn’t result in the same potatoes as the parent plant, there’s lots of genetic variation. Potato breeders plant out thousands of seeds, check out the results, then keep replanting the most desirable potatoes for many years or generations to get new commercial varieties—apparently, this is the way new potatoes are bred.

Meanwhile, it apparently only takes only two seasons and one generation to breed genetically stable new potatoes, so for the small farm or home garden, as opposed to the big potato breeder, this seems like a viable way to go. Harvest seed one season—you can hand-pollinate to cross two varieties—plant out the next and select your favorites. Those tubers should be stable and ready to go, you just have to build up a quantity, which takes another season, unless you need hardly any at all!

And, the fruit are poisonous, rich in solanine, not for eating. Potatoes, tomatoes, peppers, eggplant and tobacco are all members of the “deadly nightshade” family, all prone to having toxic parts (potato fruit are somewhat similar to little, hard green tomatoes). Interesting! Since they suddenly appeared this year on two varieties, I’d guess it was about the weather!

Inside the potato fruit

Since this is such a popular post, being dug up over and over via Google, I’ve started to update the article as I discover more. I’m not marking the changes. This is unusual. In general, I don’t edit old blog posts, and clearly mark the updates when I do!

158 thoughts on “Potato fruit”

  1. I have removed all the potato fruits from my plants and disposed of them as they are toxic. Can I eat the actual tubers from these plants or are they also harmful?

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  2. When I saw the fruit developing early on I thought I had a tomato plant that popped up in my compost. Finding no information in any of my garden books , and I have a lot of them, I took to the internet and found your Blog. My red potatoes put out fruit. Not knowing what to do I just replanted them after harvesting my potatoes yesterday. The big surprise was when I dug a red out that was 6.5 inches long.

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    • My mother-in law has these things this year and we live in Minnesota, we had never seen anything like this ever.. My sister found your web sight and sent it to me and I think that this is very interesting.. I will Honest I tried on of them things that was growing and they are very bitter, I spit it out right away, I had not lasting effects from it, but now my sister did the same thing not sure if she left it in her mouth longer then I did, but now she has been having some stomach issues. Nothing that has sent to the hospital just some bought of Nausea. Thanks again for the info and will be looking for more interesting things to come in the future…

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  3. Hi

    Grief thanks for all the info – this is the first time I’d ever seen these fruit, am hanging onto the seed for next year and see what happens. Thank you all for the info – weather has been sublime here -heat for once !!

    M

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  4. I have also found potato fruits on my Maris Piper potato plant! At first I thought they were tomatoes, and that I was going crazy, but this has explained everything well. Thank you!

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  5. Tuesday 24/7/13

    I’ve also had these “grapes” on one plant of my small Maris Piper crop this year. Never seen them before. I can post pics if anyone wants.
    Thanks for info.

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  6. after growing maris piper and king edward close together for the past three years i have noticed fruit for the first time on the maris pipers only ? i will harvest them and have fun next year trying to grow from seed. Thanks for the info on this site.PS does any body want any seeds ?

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  7. Just found a bunch on mine… don’t remember what variety, they were grown from refrigerator left overs.
    I’m towards the North of Sweden too, been very warm and very very wet this last two weeks, plus the previous dry weeks I watered a lot. Recent thunderstorms and floods have done a number on my plants and uncovered a few tubers early too, they already look awesome too. Huge compared to this time of year. Quickly recovered them to keep them going a little longer.
    I hadn’t even seen the fruits until the torrential rain had forced them off the plants. Will certainly save for experimental growth for my girls for next year.

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  8. I’m in great lakes area of US in Michigan. 2013 has been a very wet summer with hot and cold periods. Potatoes fruited for the first time (in 15 years!). I planted small white potatoes, no variety listed. Soil was last years planting mix from many big flower pots dumped into a new raised bed. Usually I plant whatever sprouts in my veg drawer. Best results ever were with the purple fingerlings from a mixed bag of “gourmet fingerlings”. The purples are still self-seeding 5 years later and they are prolific (like weeds with food attached). I don’t have potato bugs. Every year I plant french marigold plants on the sides of my potato, tomato and eggplant beds. I also keep last season’s marigold seed and sprinkle in beds like grass seed. Since I learned that trick years ago, I have had NO BUGS. I will save and plant these potato seeds to see what comes up. Do they need to be started early indoors since they are seeds? Thanks everyone for this info, especially about them being poisonous. They do look exactly like cherry tomatoes.

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  9. I am growing potatoes for the first time this year and found fruit on one or two of the plants. I’ll probably try growing them because I love the idea of growing my own from seed!
    Thanks for the information. (and yes, Google had this as the first result after wikipedia)

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  10. Thanks for the blog. I was home growing some Idaho potatoes that rooted in my pantry and one plant grew a fruit on it. Nice to know not to attempt to taste one lol

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  11. Google strikes again! :) I was out weeding in my Yukon Gold patch tonight and found a fruit, took a pic of it. I’ve gardened for 40 years, never planted potatoes until the last 3 years. First time seeing a fruit, I’ll look for more and save the seed. I planted a few Russets that had started sprouting in the cupboard, maybe a cross with the Yukon Gold.

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  12. I have grown potatoes in potato grow bags in my back garden for around 4 years now and this is the first year I have had the fruits appear. My variety are all maris piper this year.

    After the internet search we realised what they were and had to cut them all off the plants-I have filled a carrier bag with the fruit off my plants (6 potato growing bags in all).

    The dog had also been playing with them and eating them, I am not sure how many she has eaten- I have been clearing up just reminantes of the skins for a few days. After my little education I rang our vets as she has had an upset stomach and diarrhoea for a few days. Our dog ended up being kept in over night to keep an eye on her for suspected Solanine poisoning.

    A rather expensive lesson and next time I will be keeping a closer eye on the potatoes and removing them at the first sign of them appearing.

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  13. Hi, we just harvested our potatos and the plants had ober 50 fruit on!! Not sure what to do now…
    We are first time growers and this post has been great, but still not really sure, do we cut the fruit open and plant the seeds straight from the fruit? Or do we just plant them as full fruit? And do we do it now or wait till next spring? We have a mixed-veg garden, which is only small and don’t want the potatos to dominate it all like this year!
    Any advice would be gratefully received! Thank you.

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  14. Ive just stumbled upon this as I have also got these tomato looking bunches on some of my plants.
    May I ask when can I replant seeds?

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  15. I just found these on mine, planted from sprouting store bought reds in July. How do you store them over the winter for next spring crop?

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  16. Thank you for the info posted on the fruits of potatoes I would have tried it thinking it is harmless because potatoes are edible anyway! You saved me from a very bad experience.. Should I just cut them off and properly discard them or put on compost heap
    Many thanks Geeta

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  17. I watched these grow on my potato plants and was curious as to what they were. Searced and found your site. I have harvested my potatoes just today and will cut the fruit open and leave in water for all the seeds to float to the bottom. Then I will dry them out and plant in the new season. Thanks for the info. I was just going to discard them but now I know I can use them.

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  18. Thanks for all this info, guys! Noticed the green balls on my potatoes so thought I would ask Dr. Google, and a mine of info appeared! My first time growing potatoes, have experimented with both a normal raised bed and a few tyre towers so it will be interesting to see which method produces the most potatoes. I’m in the southern highlands, Australia, so am awaiting my first crop – fingers crossed!

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  19. Just returned from vacation last night and rushed out this morning to check on my garden. Surprised to find fruit on my potato plants. I had flowers before I left 5 days ago. This is my first try at gardening in a new state (TN) and I planted a variety of veggies, just to see what would grow. I saw the fruit and immediately came in to Google my find. It has been an extremely wet Spring and I haven’t had to water much. Thanks for the info, I will save the seed for next year and experiment.

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  20. First year i am trying potatoes i have them on just about all my plants i only planted 13 plants. Thanks for the good info

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  21. Hi guys I just dug up Desiree spuds when I looked I had tomato looking fruit too. My first time growing!! So weirded

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  22. I just saw potato seed pods for the first time today after many years, when I was doing some garden cleanup, after being away for a week.

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  23. Potatoes grew out of my compost and in several of the pots I used the soil for flowers – and while I have never grown potatoes before, loads have come up and all have these green fruit on and there must be dozens, so I shall collect and use next summer and see what grown. Thrilling and thanks for this blog… really helpful.

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  24. I have them here in Donegal on British Queens beside Kerr’s Pinks a lot of extra labour to save seed and wait for a couple of years don’t know if it would be worth all that work, if planting the seed how early would be recommended.

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  25. I just saw these on my purple potatoes. So neat! I now need to figure out how to save them for planting next year :)

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  26. I am growing Desiree Red potatoes for the first time, and i have these fruits on them,I have read all the write ups about them, what i need to know is do i take out the seeds from the fruit and dry it for planting next year or do i plant the whole fruit ?

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  27. Planted seed potatoes this year, Yukon is the only variety I know of. All came from western farm in Santa Rosa, CA. For the first time I have fruit, and not just one or two but quite a few. Look just like baby tomatoes, duh. I’ll plant them next year. Who knows what I will end up with. FYI. I live in Central Marin. Kentfiled.

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  28. Just found some on our potato plants in Gloucestershire UK. Never seen them before. (Kestrel and Desiree) mixed together so I do not know which!

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  29. Well is this the longest living thread?

    Ok, it’s green, blue or white, it tastes like a bitter kiwi, and gives you diarrea. ¿Is there no way to cook them to eliminate the solanine? Are them all bitter? As much as I investigated I know that you can eat between 40 and 300 grams of fruit without getting intoxicated. Btw it’s a shame the fruit it’s toxic, just imagine the productivity if not!

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  30. I have over hundred of these berries tiny like the size of a pea. Dark purple black… from my organic purple new potato. Pulled lots of the very plants out and found a ping pong ball sized perfect purple new potato! So I guess it does grow more potatoes!

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