Wednesday, August 26, 2009

Potato Box Update

Back in May, I planted 3 pounds of Inca Gold seed potatoes in a 3' x 3' x 3' cedar box on a strip of land next to my garage.

As the seed potatoes sprouted and sent up vines, I added a new board to each side and covered almost all the new growth with fertilized potting mix. In a couple months the vines were all the way to the top. The idea, cribbed from an article in the Seattle Times, was that tubers would sprout along the entire length of each (covered) vine to fill up the entire box with up to 100 pounds (!) of new potatoes.

Ordinarily potatoes are planted in the ground and produce tubers at the ends of the roots. Here's what a potato plant looks like in normal growing conditions:


By continually covering the growing vine with soil, I'm turning the green vine into a very long tap root. Off of the entire length of that root, the plant will produce tubers.

If you're looking for instructions on growing potatoes in smaller containers, Love Apple Farm has a good tutorial.

This pic, taken August 14th, shows plenty of healthy vines climbing out of the box. A good sign.

They started setting up flowers around the 1st of August. Since these first blooms I haven't seen many more. That doesn't seem right.

Two weeks later, it's time to check for new potatoes, at least according to this link.

"You may begin to harvest your potatoes 2 to 3-weeks after the plants have finished flowering. At this time you will only find small "baby" potatoes if you were to dig up a plant. Potatoes can be harvested any time after this, by gently loosening the soil, reaching under the plant, and removing the largest tubers, leaving the smaller ones to continue growing. If you want late potatoes for storage, wait 2-3 weeks after the foliage dies back."

They said baby potatoes, nothing about peanuts.

After I took off the bottom board on one side, I stuck my hand in about 5" looking for potatoes. All I found was a peanut, probably left by a squirrel when there wasn't much dirt in the box.

I'm going to let them grow a little more and then pull the whole thing apart in mid September in search of my 100 pounds of potatoes.

Stay tuned.

[Update 10.6.09, Potato Harvest results]


Aly said...

Mid-Sept? I'll make a note to check in on you for the newsletter. And maybe for a potato.

Bruce said...

Nice story on our roof gardens Aly. I only saw an email version, is it anywhere online/linkable?

art and chel said...

Looks like an awesome technique. Do the potatoes grow into the ground or only into the medium that you put in the box? And do you continue to add slats as the vines grow upwards?


Bruce said...

Hi Art,

I think they grow down a little, maybe 6 inches.

It's a good question, one that made go looking for a schematic of a potato plant. I found a decent one and added it to the original post, hoping that it'll clear things up.

Yes, as the vine grows you add slats to the side of the box. That lets you add more dirt. I tried to leave a couple inches of vine above the dirt all the time, rather than covering it completely.

It's been an interesting experiment. I hope it pays off next month.

art and chel said...

Will be looking forward to seeing the results. I don't doubt you will have plenty of papas for your root cellar!

In your opinion, you could do this project completely "above ground?"

Bruce said...

Growing potatoes in pots works well, you should be able to grow them in a box too. Might want to leave a bit more dirt below the seed potato though.

Aly said...

Hey, Bruce, thanks... no, not at the moment. It's just an email that goes out, and every four weeks, or four issues, it expires. In the coming days/weeks I am hoping to archive past issues on a site somewhere. I put the story up on streetsofwicker.blogspot, though, and my neighbor Eric wrote about GRG on his blog at

The photos from that day are at -

RVcook said...

Your "potato" harvest reminds me of the time in the 70's that I bought one of those mushroom farms in a box that the seed companies sell. After waiting anxiously for the flush of mushrooms promised in the instructions, I think I got 4 teeny-weeny mushrooms from it, about the size of the tip of my pinky finger. Never tried "that" again...

It was probably a little early. I note that the potato farmers up here have started harvesting just in the past two weeks so perhaps with a little more time, you'll get a better harvest.

Have you had any problems with potato bugs?


Bruce said...

Hi Donna,

Yeah, I'm hoping for better results in a couple of weeks.

No potato bugs, but I've seen a few spotted cucumber beetles on the potato vines. I think that's what they were.

All my cucurbits were hit with bacterial wilt and mildew. I read that the spotted cuke beetle harbors the bacteria in it's gut overwinter and tracks it all over in the spring.