April 1, 2012

Plant Up: How to Build a Potato Tower


Last season’s potato crop, like all our other crops but chile peppers, was pretty much a bust.

Chickens pickin' at potato tower fixin's
We plant three varieties in rows in one of our raised beds after mixing two-year-old composted horse manure into the soil. It was a rich, black, loamy bed, and once the seed potato pieces went into the ground, hopes were high for some tens of pounds of Yukon golds, russets, and Peruvian purples in late summer or fall.

Nearly all of them sprouted, and as the sprouts grew, we carefully mounded fresh dirt around and up the stems, a maneuver meant to keep sunlight off the spuds that develop on shoots running off the mother plant. If the taters get light during development, and even after they’ve been picked, they tend to go greenish on and under the skin and turn toxic. For the science minded, the green layer contains the alkaloids solanine and chaconine, which are related to and as strong as strychnine. Nasty stuff, of course.

Cut and "calloused" seed potatoes
But in 2006, The Journal of Agricultural and Food Chemistry published a study in which researchers exposed four common varieties of potatoes to simulated grocery store lighting for 10 days, and then measured the toxic green. Most of it was in the skins in varying amounts, sometimes over the safe level for human consumption. But there were no dangerous amounts in the flesh. The conclusion was essentially what our mothers taught us: Pare off the green layer and eat the potato. (The researchers did offer one warning, though, saying that people who eat pared greenish spuds every day could still build up toxic levels of the alkaloids.)

That was of little concern anyway in our crop last year. The plants yellowed and fell over early, showing some kind of blight. We dug them up and found maybe 10 pounds of new potatoes – just about the same amount we had planted in the first place. They were delicious and too quickly gone.

Between blight, Japanese beetles, drought, and persistent insufferable heat, we got little else out of last season’s plantings.

We’ve gone on the offensive early this year. Already treated with milky spore last year, our beds and the surrounding areas have also been dusted, and soon will be again, with food grade diatomaceous earth. This fossil product is comprised of countless razor-sharp microscopic particles that slice up the innards and outers of any grubs and other destructive bugs that encounter them, killing them within a few days. But it can be safely consumed by humans and other sizable beasties, including pets and livestock. Chickens are treated with it to control mites, as are dairy cows and beef cattle and many other animals. It is, in a literal sense, safe organic pest control. We have high hopes for it. (I should stress, again, that only food grade diatomaceous earth should be used for this. Another sort, used in swimming pool filters, is not safe for gardens and livestock.)
Seed potatoes on first layer of tower

Because we’re planting more and different varieties of vegetables this year, we didn’t want to give over a whole bed to potatoes, just in case they were again a problem crop. I thought about growing some in a 50-gallon drum, and still had one left from the three I brought with us from Detroit, where I’d found them clean and cheap.

Then Vicki ran across something online that we’d never before seen – a “potato tower.” While the poster credited Mexican growers with the invention, I haven’t been able to find any corroborating evidence. Wherever it came from, though, it makes sense, is inexpensive, and seemed well worth trying.

It’s also simple. Form a length of wide-mesh light-gauge wire fence into a cylinder, stand it on end, line it with straw, and fill it with layers of soil, planting seed potatoes as you go until it’s full. The plants sprout sideways through the straw and wire mesh, the taters grow inside the tower, and when harvest time comes, you tip the whole thing onto its side and collect the treasures within. No forking. No damage. Minimal toil. And reusable soil, if only for the compost bin.

Top layer of potato tower
Happily, soon after we moved in I discovered several folded lengths of just the kind of fencing I wanted, discarded in the woods at the front of our homestead. I retrieved it last weekend, unfolded it, straightened out the kinks, and rolled it into a cylinder about two feet across. Because the fencing is four feet wide, when stood on end it made a four-foot-tall cage for the potato tower.

We decided to place it in one corner of the garden area where it will get full sun. Although the online instructions told us to fill the tower with non-manure compost (without explaining why), I chose to use growing material we had on hand: Canadian peat, some bagged planting mix, and dead leaves. We also had a couple of bales of straw in the shed to replenish the bedding in our chicken house and nesting boxes.

A tower of taters
Fortunately, my hands are small enough to fit through the wire mesh, making it easier to line the cage with hanks of straw, going about a foot up from the ground. Then I dropped in a thick layer of dead leaves, topped by enough mixed peat and soil to come to the top of the straw. The day before, I’d cut russet seed potatoes into chunks, leaving at least two eyes on each, and allowed them to “callous” overnight – a precaution against inviting blight. Eight of these chunks went around the perimeter of the dirt layer, just inside the straw lining, eyes pointed outward.

Then I lined another few inches of the cage with straw, and repeated the procedure, again and again, until the cage was full and the tower was complete. The last layer was different only in that I added three extra seed potato chunks in the middle of the circle, which will sprout and grow upwards, while runners – and their attached new potatoes – will grow down into the interior of the tower.

In all I planted nine pounds of seed potatoes – four of russets and five of Yukon gold. If all goes well, what comes out of the tower, properly stored, should meet our needs for much of the fall and winter.

And as a bonus, it will have happened on just two square feet of ground at one corner of our gardens. That’s economy, times two.

1 comment:

  1. i have read about a similar method using stackable frames. every time the potato plant breaks the surface of the soil you stack on another frame and add more soil. the idea is that the plants will continue to grow upward while producing potatoes in its wake.

    I can't wait to hear how well the tower method works!

    ReplyDelete