Vegetables

Determinate and Indeterminate Potatoes

Determinate potato (left), indeterminate potato (right). Ill.: http://www.supercoloring.com, montage: laidbackgardener.blog

Most serious gardeners know the difference between determinate and indeterminate tomatoes (Solanum lycopersicum). Determinate tomatoes are the shorter ones, the ones that don’t necessarily need staking. They grow to a certain height, then stop growing. They also produce most of their fruits all at once. Many early tomatoes are determinate.

Ill.: organicsoiltechnoloogy.com

Indeterminate tomatoes are the tall ones. Staking or caging is required and they keep growing taller and taller all season. They produce fruits over a long period and indeed, in tropical climates or heated greenhouses, produce continuously. They’re usually mid-season to late types.

So, that’s what you know. But did you know that potatoes (Solanum tuberosum), also come in determinate and indeterminate varieties and that this can influence how you grow them?

The difference is that this mostly happens underground. 

Determinate Potatoes

Even if you mound determinate potatoes, they won’t form an upper layer of tubers. Ill.: http://www.klett.de

Determinate potatoes produce a single layer of tubers just below the soil surface. They produce fewer tubers than indeterminate ones, but they tend to be earlier, even much earlier, most maturing in 55 to 70 days. In short season climates, only determinate potatoes may have time to produce full-size tubers good for storage. They also have shorter stems not given to flopping.

Plant determinate seed potatoes (small tubers) about 4 inches (10 cm) deep. There is no need to mound up soil at their base, but mulching can be of great help, ensuring that the tubers are not exposed to the sun. (Those touched by the sun will turn green and be inedible.)

‘Yukon Gold’ is a common short-season determinate potato. Photo: http://www.gardensalive.com

The following varieties are among the more popular determinate potatoes:

  • ‘Adirondack Blue’
  • ‘Adirondack Red’
  • ’Chieftain’
  • ‘Dark Red Norland’
  • ‘Dakota Pearl’
  • ‘Gold Rush’
  • ‘Irish Cobbler’
  • ‘Kennebec’
  • ‘Norland’
  • ‘Purple Majesty’
  • ‘Ratte’
  • ‘Red Norland’
  • ‘Red Pontiac’
  • ‘Russian Banana’
  • ‘Sierra Gold’
  • ‘Sierra Rose’
  • ‘Superior’
  • ‘Viking’
  • ‘Yukon Gem’
  • ‘Yukon Gold’
  • ‘Warba’
Ill.: West Coast Seeds

Indeterminate Potatoes

These potatoes are capable of producing tubers at multiple levels, so, although you plant them at the same depth as determinate potatoes (4 inches/10 cm), you will need to keep mounding soil, mulch, chopped leaves or straw up around the plant as the season progresses. This mounding will not only help support their tall, often floppy stems, but tubers will form in the increasingly high mounds, to a maximum of up to about 1 foot (30 cm) above the original level. They’re also the potatoes used in “potato towers” and “potato bags.” 

Indeterminate potatoes are often growing in potato bags (above) and potato towers. Photo: http://www.dhgate.com

Indeterminate potatoes produce more tubers than determinate potatoes, but need a longer growing season. Some are mid-season (70 to 90 days) varieties, but most are late varieties (90 to 110 days, even 135 days). Not all late varieties are adapted to short-season climates. 

The following varieties are indeterminate, at least to a certain degree:

‘French Fingerling’ is a mid-season indeterminate potato. Photo: http://www.specialtyproduce.com
  • ‘All Blue’ (‘Russian Blue’)
  • ‘Amarosa’
  • ‘Bellanite’
  • ‘Bintje’
  • ‘Butte’
  • ‘Canela Russet’
  • ‘Desiree’
  • ‘Elba’
  • ‘French Fingerling’
  • ‘German Butterball’
  • ‘Green Mountain’
  • ‘Katahdin’
  • ‘Lehigh’
  • ‘Maris Piper’
  • ‘Nicola’
  • ‘Pink Fir Apple’
  • ‘Red Cloud’
  • ‘Red Maria’
  • ‘Russet Burbank’
  • ‘Russet Nugget’
  • ‘Strawberry Paw’

Helpful Hint: No matter what type of potato you grow, you can tell the tubers are ready to harvest when the foliage begins to die back.

How to Tell?

Oddly, potato suppliers rarely seem to mention which type of potato—determinate or indeterminate—they sell. They tend to stick to the terms “early,” “mid-season” and “late” in their descriptions: helpful information, to be sure, but it doesn’t necessarily tell you which ones will produce tubers on mounded stems and which won’t. Mid-season varieties, for example can belong to either group.

Of course, you can find out if a potato is indeterminate or not by growing it! Determinate potatoes rarely grow very tall and are often early to bloom. However, if the plant’s stems just keep growing up and up, it’s indeterminate, a fact you can confirm by mounding the stems and checking to see if new tubers form in the added layer.

Still, knowing in advance which potatoes are determinate and indeterminate would really help gardeners, especially those who want to experiment with growing in towers and bags, so, potato suppliers, would it really be so hard for you to just add one more word to your descriptions: either determinate or indeterminate?

Thanks so much!

Larry Hodgson is one of Canada’s best-known garden communicators. He has notably been editor-in-chief of HousePlant Magazine, Fleurs, Plantes et Jardins, À Fleur de Pot and Houseplant Forum magazines and is currently the garden correspondent for Le Soleil and radio garden commentator for CKIA-FM Radio. He has written for many garden publications in both the United States and Canada, including Canadian Gardening, Harrowsmith, Horticulture, Fine Gardening and Organic Gardening. He also speaks frequently to horticultural groups throughout Canada and the U.S. His book credits include The Garden Lover’s Guide to Canada, Complete Guide to Houseplants, Making the Most of Shade, Perennials for Every Purpose, Annuals for Every Purpose, and Houseplants for Dummies, as well as nearly 60 other titles in English and French. He is a past president of the Garden Writers Association (now Garden Communicators International) and the winner of the prestigious 2006 Garden Media Promoter Award offered by the Perennial Plant Association. He resides in Quebec City, Quebec, Canada.

49 comments on “Determinate and Indeterminate Potatoes

  1. Thank you! I will humbly admit, I had no idea. Since I’m hoping to plant my potatoes this week, this is a huge help.

  2. Purple Caribe is the most successful variety we grow. Do you think it is determinate or indeterminate?

  3. I did not know this!

  4. I haven’t had a good baked potato in a long time. 🙂

  5. Yes, it would help, especially since some of the early sorts are rather perishable. For example, Yukon Gold is ready early, but does not store well for a long time after that. It would be nice to grow some indeterminate sorts for later, especially if they can be stored a long time. Mid-season does not say enough. Of course, it helps to be familiar with the particular varieties.

  6. Are all fingerling potatoes determinate?

  7. Are Dutch Cream Potatoes Determinate or Indeterminate? Helpppp? lol

  8. Pingback: Potatoes – Cross Road Gardens

  9. Red Pontiac is listed as being both? Is that a mistake? Or is there a variety of each?

  10. Steve Shaw

    Are Irish Cobblers indeterminate?

  11. Tech Gal

    Thank you so much for this. I have grown potatoes for years and didn’t know this. Trying to hill them when they didn’t need it and grow in dirt that was to hard for them to grow in! Now I know which to grow in bags & containers.
    I have listed them and will grow better from now on!
    Wire worms are the death of us!

  12. Hi, I will be planting russet burbanks this year as inderterminate in towers… hope that will work. But I also would like to have a red skin rather large variety. Are there any large red skin potatoes that are indeterminate?

  13. Are Yellow Finn Potatoes determinate or indeterminate?

  14. Are All Russets indeterminate?

  15. Themadchemist

    Great topic and content! I just started growing 8 months ago, I don’t know when to mound and where not too……

  16. Brian the chilli man

    Tried roosters last year not knowing if they were determinate or indeterminate. Dug through a foot of nothingness when I took the side off my tower, clearly determinate :'( Got a nice yield for a 2*2 tower though 🙂

  17. Hi..great info! thank you!

    question: is dakota pearl determinate? thank you for responding …that resume is impressive!

  18. Is the Ludmilla potato indeterminate?

  19. bea latour

    Great site. I would like to know why kennebec potatoes are sometimes listed as determinate and sometimes as indeterminate.

    • I can’t say. I built my list based on the information I found in government publications. I have not grown all these varieties myself.

  20. Paul Baranski

    You have a picture of French Fingerlings, and the caption reads “determinant” and then in the list below of indeterminant varieties, the French Fingerling is listed.
    I am about to plant these, and am wondering which of the two it is, so I know whether to hill or not, thanks.

  21. How about Yukon Gem and Prada? Thanks!

  22. Penelope Potter

    THANK you for this information! It really makes me wonder why this isn’t common knowledge (like tomatoes).

    So with this “new” information in mind, I guess my question would be for indeterminate potatoes grown in pots. If seedlings aren’t growing at the same rate, let’s say one is 6 in high and the other is barely popping through the soil, do you go ahead and cover them up? Will that “drown out” the one barely popping through?

  23. Thank you for the concise and explicative post! I just had my first container harvest and was wondering what went wrong, because the tubers were only at the bottom of the container. I stumbled upon this blog entry and now I know that I simply planted a “wrong” determinate variety. I didn´t even know that potatoes had determinate varieties 🙂 Thank you for explaining clearly how it works. Next year I just have to find an indeterminate variety.

  24. Sue king

    Will topping an indeterminate variety (katahdin) help them put energy into the potato and stop new growth? I couldn’t find an answer to this, so I tried it. This is the first year I learned of indeterminate by accident. Thanks for the info.

    • It probably will make little difference, but do remember you’d theoretically be reducing the energy, since you’d be reducing the foliage and plants get all their energy from the sun via their leaves.

  25. Hi, I’m wondering if you know of any indeterminate purple varieties. I havent really grown the plants correctly to be able to observe them growing more tubers up the stem but they have been growing since april and are just now only some are starting to die back in october. The stems are purple and the early foliage is mostly purple but then turns green. The skin of the tubers is not quite black but a dark purple and the flesh seems to vary from mostly white to a purple about half as dark as the skin.

    On one plant that had its stem base mostly rotted away, it made some small potatoes on the first few nodes up the stem. Seems like a last ditch effort to perennialize, not sure if that is hard evidence that its indeterminate.

    I believe I got the original tubers from a baby potato medley.

    Hopefully the details help rather than complicate.

  26. In South Africa we have a variety called Up To Date – Known locally as UTD. I can’t find out if this is determinate or indeterminate. Any ideas?

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