The Four-Square-Foot Potato Tower
Apr 29th, 2009 | By Guest Post | Category: Gardening[ Another great post from Rob at One Straw. ]
A huge focus of this blog is finding creative, sustainable ways to eek more produce from small spaces. I also love growing calorie crops, especially potatoes, and furthermore I really enjoy building things. So when a friend recently recommended the use of potato towers, I was very interested. So yesterday I was off to buy materials for several compost bin orders I have and wouldn’t ya know? 2×6 pine was on sale.
The theory is simple – solancea plants will root from any stalk that has ground contact – I’ve seen both peppers and tomatoes rooting from their stalks. The important part with potatoes is that they will lay tubers anywhere between the original “seed” potato and the soil surface. Every time the potato plant gets about 6 inches above ground, add more soil – this is why you mound potatoes in the field. These towers just take the mounding to crazy logical conclusions – the tower is essentially a three foot “mound”. What I like most about this kind of tower is the ability to “sneak” potatoes as the season progresses by removing a lower strip of 2×6 and grubbing around. As most suburbanites don’t have root cellars (yet!) this is a huge plus if you are growing 100 lbs of spuds. Also, as the sides are opaque, spud production will occur right up to the sides, maximizing space and using less water compared to wire mesh designs. Also, the lumber avoids some concerns that may be present with using old tires. Old garbage cans, etc would also work.
The only major change I did for mine was that I used 2×4’s for the uprights as I had 10′ of them laying around the garage and I also put a sheet of cardboard under it to thwart the quack. Speaking of which, this could be considered a hyper productive way to sheet mulch - cardboard out next years beds, and build potato towers along them – one could get (in theory) 600 lbs of spuds form one 20-foot bed (6 towers with 18-inch spacing) and when the towers come down you have a raised bed about 2 feet deep with compost when you’re done. Hmmmm…
Planting the tower is easy, I took four medium seed potatoes (1 lb exactly) and cut them in half. In the spirit of science, I used one each of Kennebec, Purple Viking, Carola, and Yukon Gold to see which liked this method more. The growing medium I used for the first layer is two-year-old leaf mold, to which I added some pelletized chicken manure for nitrogen as it looked a little “carbon-ey”. Weather here is mild and rainy, so they should be sprouting in no time. The only down side is that right after the photo shoot, our new adolescent dog decided that this was a fantastic play pen and tore into it with abandon – I think I found all eight seeds, but she may have eaten one or two.
The claim is that the towers will produce 100 lbs of spuds with about 1 lb planted in 4 sqare feet. That is freakish considering a record yield for field sown spuds is about 14:1; I was very pleased with my 8.5:1 last year. In typical culture, 100 lbs would take at least 75 square feet, but more likely 150. I am stoked to see this work and will certainly keep you posted. Other great advantages – you do not need any heavy equipment to grow these – and harvesting is super easy. Just be sure to save the soil somewhere for next year – mixing it with fall leaves and grass clippings in a compost bin would be a fantastic way to rejuvenate the soil.
Couple of post-scripts. This thing is crazy overbuilt – I would feel comfortable parking a car on it if it had a cross tie across the top! I think the prime driver of the dimensions is cost. In the irony of modern economics, 2×6×8′ lumber is cheaper than 1×6×8′ lumber. Also, pine rots quickly, so using 2x lumber will buy you a few extra years -though by Year Four I expect these to be falling apart. If it works I will likely build the next one using cedar decking for the sides and 2×2 cedar for the uprights. That should last a decade, but would cost about double. Another advantage would be that it would weigh half as much – this thing is heavy when built!
To make it more fun, we will likely be painting the sides with the kids – I have the idea of making each side a different person, and then we can mix and match the parts each year to create silly combinations. I would also like to enlist my wife (waaaaay more talented artist) to paint a picture of a potato plant with a “soil view” of roots on one side.
All in all the total cost was about $30 (8 2×6×8, screws, and 12′ of 2×2) and about an hour of time in the workshop -mostly becuase my kids were running the screw guns and they are 5 and 7. If you can truly get 100 lbs of spuds that is crazy cheap – down to literally a few cents per pound over the lifetime of the tower. Combine that with the ability for literally every single homeowner to grow all their potatoes for a year in as little as 8 square feet, this could be huge!
