Potatoes: Please Explain.

[z]

Once the tuber has been planted, the stem grows up, and is it from the stem underground that the new tubers grow?

What happens to the original tuber?

If the tubers all produce "eyes" or buds, why do these not all develop into new stems? If they do, can a tuber ne "connected to" more than one stem - ie the original one it grew from, and the new stem it sends up?

When I have seen tubers they always have plenty of "eyes," but in pictures of underground potatoes, the tubers are simply growing from a single line from the original plant. They have no or few "eyes." The individual potatoes have no eyes. How can they be said to produce more plants? If you see a clump of potato plants, does that mean each stem originates from a single tuber?

Where are the roots?

Pics would be good

[TZ -OH6]

One or more stems will grow from each eye (some eyes have multiple buds). Roots form at the bottom of that stem and the seed potato withers away. Farmers usually plant seed pieces that only have one or two eyes which is why the pictures look the way they do.

If you plant a whole big seed potato with many eyes you will get lots of stems coming up but they act as individual plants competing with each other for light and soil nutrients so productivity will be lower than with one or two stems per hill. A hill is whatever grows from one seed piece.

The tubers grow off of stolon runners that come off of the lower portion of the stem. Most commercial varieties are determinant and the runners come off only at the lowest part of the stem over a short time period. Ancestral and some long season varieties may continue to put out stolons from higher up if the stem is burried. You can even get air tubers from the leaf and branch nodes some times.


I got my hands on a single seed tuber of a rare variety this spring that put up several sprouts from each eye. It was a small thing the size of a walnut so started it in a pot and then when the sprouts were a few inches long I dug it up, broke off some of the rooting sprouts and potted them up for a time before plant out. I ended up with five hills from one small seed tuber.

[z]

Thanks, its a great explanation. I'll try and remember it!

[cynthia_h]

Any time TZ -OH6 describes a plant's habits, pay close attention. Also see this thread, which contains both photos and an illustration.

https://www.helpfulgardener.com/forum/viewtopic.php?p=147116

Cynthia H.
Sunset Zone 17, USDA Zone 9

[z]

Thanks.