It's really cold and windy out here on the Plains of Eastern Colorado, but it's also the time of year that I start to think ahead to the coming season.
By this point in the year, the sweet potatoes I reserved for slips have been chilling out spending time in my sweet potato "secret weapon", a used wine fridge which keeps them at the perfect 60 degree temp until I put them in warmed soil to get them growing. The things you have to do when you have no root cellar!
I do have to remember to open the fridge about once a day or so in order to let them breathe. A hassle, yes, but not without some benefits.
I get the payoff of knowing my operation is circular (I grow, harvest, eat, and have some to grow next year's crop), and I am sure to have varieties I know will do great in my area.
Once I'm about 4 weeks or so out from planting (you don't want to plant out til maybe end of May or early June where I am), I'll get my sweet potatoes out, toss any that are mushy or that just don't look right, and put them in dirt on a heat mat. Couple of weeks in the dark and they start to sprout.
If you got the slips, you have to have somewhere to put them! You can always put the slips in the soil like a regular plant. If you go that route, a couple weeks prior to planting out, cover the soil with black food grade plastic and then cut slits to put the slips in. The plastic will help hold moisture and will start the soil to warming up.
If you want to try towers, however, I'll give you my plan.
It turns out that sweet potatoes, unlike regular potatoes, which fail in towers tower due to soil temps regularly going above 80 degrees, do great when planted in towers. They love the warmer soil (which gets warmer sooner by the way--a bonus for those of us with short growing seasons), and towers are an efficient use of garden space. Instead of taking up precious square feet in my raised beds, I can put a couple towers on my patio and get lots of taters!
The towers above were pretty were pretty easy and cheap to make. I'll share my design.
I first went to my local farm store and bought some "combo" panels, these are feedlot panels but the spaces between wires get smaller at the bottom. You don't have to use them, but feedlot panels are about the right height (50") and are heavy gauge wire so they can be self supporting.
Decide on how big across you want yours to be. I chose about 3' feet across, this lets me fit 3 or 4 slips around the edge and still fit well on my porch. You could go bigger if you wanted, you could go smaller.
No matter the diameter, you would take and multiply by 3.14 (pi) to find how long to cut your panels. Using my 3', I get 3 x 3.14 or about 9.5 feet. Measuring out on a panel, I go to the nearest vertical wire to 9.5 feet and cut there. Be prepared to cut with bolt cutters, the wire is so thick regular wire cutters won't do.
I twisted the panel into a circle. Be ready because this is tough. I used a 2x4 piece wedged in to the small squares to start it bending and just worked my way around. You won't get a perfect circle, but circle-ish will work well enough. Once the two ends met around the circle, I bound them with some twisted wire.
Don't get stuck on circles either. If you find forming into, say, a square is easier with your tools, go ahead. I won't judge and the sweet potatoes won't care.
To build the containers in which I put the potatoes, I got some food safe black plastic, some stucco lath, potting soil, straw, and scrap wood.
The drawing below is a detail of the tower. It's a cross section showing the layering.
The problem you have to solve in designing a tower is that you need to contain the soil, not let the upper level crush the lower (remember that as the plants grow the upper level will be gaining weight!), be able to water the plants, and not have the soil wash out or the water puddle at the bottom.
The lowest level is easy, I wrap the black plastic for into a cylinder, slide it into the wire frame, and push it out to the edge of the wire frame. I push a stick in there and leave it poking out just a bit for drainage. Add a layer of straw, and then top with soil.
The upper level requires an extra step because you don't want to have it bearing weight on the lower level. To build a base that allows drainage, I start by putting 3 or 4 wooden slats across the wire frame making sure they bear weight on a horizontal layer. The stucco lath (cut to fit the wire frame) slides in next. It needn't be stucco per se, just needs to be sturdy metal with holes. Any sort of expanded metal cut to fit will work.
This makes a floor on which to build the upper level and you build it just like the lower. Make sure when you set these up that you are able to secure them to something. They are pretty heavy and so won't tip easily, but they can fall over, making a big mess or worse. I secure mine to a patio post, but a green T post driven into soil works too.
At that point, plant out the slips when the soil hits 60 or higher. Watch the plants and harvest after the first frost. You can get fancy with some drip lines if you want, but you can hand water them just as well. I like to water the upper first. The run off from that upper level will drain into and water the bottom layer (especially at first), so give it a minute to percolate.
If you want to try towers for your sweet potatoes, I bet you will like the results. You can grow twice the food in the space of one single tower and, while it requires soil to be filled, it doesn't have to be on dirt to work.
If you hit a snag or have a question, email me info@goodthingsfromcoryskitchenandyard.com.
Stay warm and remember Spring will be here soon!
Thanks for sharing! I hope I get to meet you one day. I love we both geek out over plants. You've been teaching me a lot about growing in Sterling. I'm still so new to the differences between here and Colorado Springs. Thanks for sharing your wisdom