The Walden Effect: Farming, simple living, permaculture, and invention.

Late planted potato experiment

Potato harvest

We had an odd potato harvest this year.  Although I planted a few pounds at the normal March date, I saved most of my seed potatoes to go in the ground at the beginning of May.  A friend had told me that he waits to plant his potatoes until after the frost free date, which gives him full size tubers late enough in the year that he can dig them in cool weather.  We rarely want potatoes in the summer, so I figured a fall crop of potatoes sounded good and followed his lead.

At first, the experiment seemed to be paying off in spades.  A third or more of our early planted potatoes often rot in the cold soil before they start growing, but my May-planted beds were chock full of potatoes.  The plants grew like crazy...but they wouldn't die.  For those of you who haven't grown potatoes, you want to wait to harvest your main crop until the plants die back, which means they've hardened up the skins of the tubers and given the spuds longevity to last through the winter in your root cellar.  So, potatoes that don't die are a problem --- you can dig new potatoes, but not storage potatoes.

Resprouted potatoWhen our first hard frost came, the last plants started to wither, so I went ahead and dug our potatoes.  My underground adventure confirmed my hypothesis --- the potatoes produced in May and June had sprouted up new plants in July and August and started putting out a second round of tubers in September and October.  This sounds good --- double potatoes --- but is actually problematic.  Some of the older tubers had rotted after giving their strength to the new growth, and I hadn't thought to hill up the second round of potatoes (who hills their potatoes in August?!), so most of them were green on one side.

Here is the yield from the 6 pounds of potatoes I planted late:

  • 10 pounds of wounded potatoes (some injured by the spade, others just troubled)
  • 30 pounds of partly green potatoes
  • 49 pounds of good potatoes

PotatoesNow, to be fair, this is an awesome yield --- 15 times as many pounds of potatoes as I put in the ground!  Even if you just look at the good potatoes, the experiment paid off since one pound of seed potatoes turned into 8 pounds of good potatoes (versus the 6.5 pounds of good potatoes I got in previous years.) 

What I'm not sure about is how long the good potatoes will last.  Several of the biggest ones have hollow heart (which is a disorder characterized by exactly what the name suggests), perhaps because I hilled them up the first time with manure.  And the second round of potatoes might not have enjoyed enough growing time to harden off for storage.  And, of course, there's the problem that I'll have to cut all that green off the problematic potatoes.

So, interesting experiment, but I'm not sure if I'll repeat it.  Has anyone else had experience with planting potatoes late?

Our chicken waterer quenches your flock's thirst with POOP-free water.

Anna Hess's books
Want more in-depth information? Browse through our books.

Or explore more posts by date or by subject.

About us: Anna Hess and Mark Hamilton spent over a decade living self-sufficiently in the mountains of Virginia before moving north to start over from scratch in the foothills of Ohio. They've experimented with permaculture, no-till gardening, trailersteading, home-based microbusinesses and much more, writing about their adventures in both blogs and books.

Want to be notified when new comments are posted on this page? Click on the RSS button after you add a comment to subscribe to the comment feed, or simply check the box beside "email replies to me" while writing your comment.

No experience with late potatoes, but let them air dry, unwashed, for a week to ten days and they should keep. Try burying the green potatoes. They may lose their green.
Comment by Errol Sat Oct 29 10:05:46 2011
What's in the green? I'm assuming bigscale growers of potatoes (like around here) can't hill all their potatoes -- how do they get around that?
Comment by J Sat Oct 29 10:47:11 2011
Here in Japan, we plant potatoes twice a year. The first crop planted in March, for a June harvest, second planting in Mid-August to mid-September, for harvest in late November to late December. So far I haven't had any problems.
Comment by Eric in Japan Sat Oct 29 10:53:55 2011

Potatoes are from the nightshades family. These plants commonly contain glycoalkaloids, which are poisonous.

In potatoes, exposure to light tends to increase the concentration of glycoalkaloids in the tubers. It also causes them to green because of chlorophyll synthesis. So the greening itself isn't the cause of potatoes becoming more toxic.

Comment by Roland_Smith Sat Oct 29 12:49:29 2011

Daddy --- I tried to pull out the really young potatoes to eat soon, but am hoping that the others will harden up as they cure. Not sure about burying potatoes to take away the green, though --- I've never heard that potatoes can go back once they turn green. You'd think that if they could, just putting them in a dark place would suffice.

J --- The green contains solanine, which is a nerve toxin. (Well, it also contains chlorophyll, which is what makes it green, but that's harmless.) I've read that you have to eat about 4 pounds of green potatoes to get really sick, but still...

I'm pretty sure the big growers hill their potatoes, probably with some attachment on the back of a tractor that pulls dirt up as the plants grow.

Eric --- A bit further south than us, people grow fall potatoes using the schedule you mentioned. I think we're just a bit too cold for potatoes to reliably get ready before frost if you plant them in late summer. It's possible that our potatoes got confused by the wet early summer, though, and thought they were on the fall track, not the spring track....

Comment by anna Sat Oct 29 12:55:01 2011
Roland --- Looks like you beat me to the answer. :-)
Comment by anna Sat Oct 29 13:29:05 2011

Potatoes have been part of our staple diet here in the Netherlands for hundreds of years. (See e.g. van Gogh's the potato eaters) So I was taught as a child that the green parts were dangerous. Of course I looked up why that was in our encyclopedia. (Yes, it was that long ago. :-) )

Comment by Roland_Smith Sat Oct 29 14:48:19 2011
I love that painting and was actually thinking about it as I dug the potatoes. I guess that's not too coincidental, though, since I tend to think of the painting every time I work with potatoes. :-)
Comment by anna Sat Oct 29 17:02:58 2011

When biking I sometimes pass through Nuenen, the place where van Gogh lived when he painted the potato eaters. Of course it's much bigger now than it was in his time.

As far as I know, he painted real people in that picture, and the clothes and house interior match the period. It is an interesting window in time.

Comment by Roland_Smith Sat Oct 29 17:30:03 2011
I live in a potato producing area of Idaho. First, they do hill up to increase yields. Second, vines that do not die off naturally are "chopped" to short stubs. This could easily be done in the home garden with a brush cutting blade on a weed wacker. They are then allowed two weeks in the ground to set the skins before digging.
Comment by Anonymous Mon Oct 31 06:13:42 2011
Thanks for the experiment update. I've never grown potatoes, but plan on doing it in the Spring. You could be saving me some wasted effort on my first tomato planting experience.
Comment by Fritz Mon Oct 31 07:04:14 2011

Anonymous --- Thanks for the first hand information! I had a feeling I might be able to cut the tops back if I had to, but wasn't sure. Glad to hear that's a possibility.

Fritz --- If you don't try crazy things the way I did, growing potatoes is very easy. I'm sure you'll have good luck with it.

Comment by anna Mon Oct 31 08:56:50 2011

profile counter myspace

Powered by Branchable Wiki Hosting.

Required disclosures:

As an Amazon Associate, I earn a few pennies every time you buy something using one of my affiliate links. Don't worry, though --- I only recommend products I thoroughly stand behind!

Also, this site has Google ads on it. Third party vendors, including Google, use cookies to serve ads based on a user's prior visits to a website. Google's use of advertising cookies enables it and its partners to serve ads to users based on their visit to various sites. You can opt out of personalized advertising by visiting this site.