Growing sweet potatoes can be an important part of your food plan. And despite the fact that Ipomoea batatas is very susceptible to cold, you can grow them even in my chilly 45N latitude. Let’s talk about the why, what, how, and how much of growing sweet potatoes in a cold climate.
Why grow sweet potatoes? Some time ago I wrote about planning a survival garden. I mentioned the fact that long-term survival means creating a sustainable food supply, and that means growing your own food.
The first articles in my survival garden series suggested a basic four-crop system to grow a subsistence diet:
They meet my criteria for yield, nutrition, and storability. In other words, they can provide you a lot of food, in places where the ‘eating season’ extends well beyond the ‘growing season’.
I also added another criterion: repeatability. That is, the ability to re-grow the crop from your own seed stock. And if you go about it right, sweet potatoes admirably meet all these criteria.
When I first decided to add sweet potatoes to our survival food plan a couple years ago, I checked around with some successful growers in my area. The variety most often recommended was ‘Georgia Jet’. It has the reputation for high yields, cold tolerance (relative to other varieties), and producing well even in a short growing season; about 90 days to maturity from transplant.
Georgia Jet Sweet Potatoes all in a row
Georgia Jet is available from a number of commercial seed sources; I got my first slips from one the aforementioned successful growers. My experience bears out the desirable characteristics of this variety.
With slips in hand, and past your last frost date, you need to prepare a seed bed. What we’ve learned from experience is that, while the soil does not need to be especially rich, it should be deep and loose for best yields. The best way to achieve this is to mound up the row i.e. make a deep bed.
Steps in the process:
Growing sweet potatoes snug under row cover
Yes, I know that row needs some weeding ;-) It was a wet and weedy season in my part of the Great White North. But the plastic mulch helped keep the weeds out and the heat in, so I got some great spuds anyway.
The books say you can expect a yield of 3 to 5 pounds per plant. Following the method outlined here, Year One we put 30 plants in a 50-ft row and got 100 pounds of tubers. This year, 20 plants yielded 80 pounds. So that seems like a good estimate.
This may be the most critical part of the whole process, from a survival food perspective. Sweet potatoes are very susceptible to chill injury, and must be cured at high temperatures (90 degrees) for 5 to 7 days, and then stored above 55-degrees for long-term viability.
This also means you need to get them out of the field before soil temperatures drop below 55. Chilled sweet potatoes won’t store, and won’t sprout. Keep them (much like winter squash) in a cool (60-65 degree) bedroom or storage closet until ready to eat and sprout.
I dug my sweet potatoes, gave them a warm rinse, and let them dry in the sun for a few hours. Then I moved them to my plant starting room, and cranked the heat to 90. Left them in there for 6 days, then brought them into a spare bedroom for storage.
Closing the Loop - growing slips. This is my next step in the coming spring, I understand the concept from my growing friends and some books on the topic, but this will be my first try. My farmer friend I bought slips from this year has been re-growing her own sweet potatoes for more than a decade, so I’m pretty sure her methods will work. The basic process:
I’ll let you know how my re-growing works, stay tuned for an update.
Here's a link with more info about growing sweet potatoes
Here's where you can buy Georgia Jet