Sweet potato plants are a nutritious option to keep the cellar full during winter! Gardeners growing large harvests will need to keep a few things in mind when harvesting sweet potatoes to prolong the life of their delicious bounty.
While the growing season is full of high humidity weather, in order to make them last all winter, they prefer cool and moisture free environments for storage. Storage can only happen after a process called curing, during which the starches in the sweet potato turn into sugars, and the tuber forms a second skin that makes it more resistant to injury.
Long term storage has been perfected over the centuries and evolved as human technology has evolved. For people living in an energy efficient home or off-grid, it is still possible to store sweet potatoes outside in the age old ‘banking method’. For gardeners looking for a more easily accessible method, storage in crates and boxes is also possible. Home cooks can also boil and then freeze potatoes to have home fries or baby food easily on hand.
To further increase your chances of a successful harvest, look for varieties known to have a long storage life, or that are best suited to your garden conditions and grow zone. Getting a healthy tuber is one of the best indicators of success for your storage endeavor!
When To Harvest Sweet Potatoes
Sweet potatoes are ready to harvest when their tubers begin to poke above ground, and their vines begin to yellow. If you know what variety you’re planting, you can better guess the harvest date by looking up their expected grow time.
The conditions in which to harvest sweet potatoes and cure your crop are very important. In order to properly start the curing, wait for a warm day (above 55F) with no chance of rain as exposure to water will slow the drying of this root plant. Be sure to harvest well before your first frost date as frost can severely injure sweet potatoes. Harvest all the plants at once, and compost the vines if they are disease-free. Be sure to start in the morning, preferably when there will be a few days of rain-free weather,
How To Harvest Sweet Potatoes
For backyard and homestead growers, there are two main methods to harvest sweet potatoes. The first is simply digging with your hands and small hand tools to extract the roots from the ground. It can actually be quite satisfying to plunge your hands into the earth and feel around in the soil for these wonderful tubers. Another method is to use a tool called a garden fork. Insert the fork well outside the growing area of the roots and lift the soil. Keep digging until you get progressively closer to the plant roots.
Do not wash your roots right after taking them out of the ground, however tempting it may be. It’s alright to leave some soil on the potatoes during the curing process, just brush off any large mounds of dirt found on the roots.
Curing Your Harvest
Immediately after harvesting, sweet potatoes need to be cured. During this process the starches turn to sugar and make the potatoes sweeter, the roots additionally lose moisture content. Flavor develops over time after harvesting, meaning you do need some patience. This is why sweet potatoes are so great for storage.
To correctly cure, leave the potatoes outside in your garden in the shade for the rest of the day after harvesting. If there is a breeze all the better. That evening, move the tubers to an area with high humidity and leave them for 7-14 days while they cure. Ideally, try to keep the temperature high, at around 80 degrees if possible. If in cooler climates, cure for an extra week.
Storing Sweet Potatoes
There are several methods to curing these delicious roots. Depending on your conditions, choose the method best for you. Each of these options use different means to prevent moisture from getting on the tuber, keep temperatures low (preferably 60f degrees) and keep the roots dry for the entire time of their storage. If done correctly, your crop may last several months or even a year.
The banking method of storing potatoes is perhaps the most complex, but it lends itself well to storing a small farms harvest. The banking method is done outside, and a hut-like structure is constructed to shield the potatoes from the elements, without taking up valuable cellar space.
To create, find a slanted piece of land, and dig out a shallow hole about six feet across and a foot down. Cover the base of the hole with straw or dry leaves and begin to layer the potatoes in keeping the pointed ends of the potatoes facing up and down. Lay the potatoes around a center upright rod to help provide ventilation. Once a layer is made, lay down several more inches of straw and create another layer continuing until you have run out of sweet potatoes. Once done, cover again with straw, and create a teepee like structure with boards around it to protect it from the elements. Lastly, cover the boards with mud. The resulting teepee-like structure should provide good storage for several months, even up to a year.
The sand method is a way to prevent sunlight and other elements that may harm the sweet potato roots. However, as this method does not allow for good ventilation, it is not as highly recommended as the others.
Place the sweet potatoes in a barrel or bucket (making sure that it is not clear and does not let the light in), and layer sand over the sweet potatoes. Make sure that the potatoes do not touch one another. Store in a warm cellar.
Crates Or Boxes
To store in crates or boxes (perhaps the most accessible way), find crates and boxes that provide good ventilation and layer the sweet potatoes inside. Try to only have one layer of sweet potatoes per box, and stack them in such a way as to allow for as much ventilation as possible.
Place the cured tubers in a cool dark closet or room with good ventilation, or a large storage closet or pantry. If you have any concern about them being exposed to sunlight, try wrapping individual sweet potatoes in newspaper to shield from light but to allow air flow. Ideally, storage temperatures would be close to 55 – 60f.
A modern and more labor intensive way to store sweet potatoes would be to freeze them. This is ideal for the backyard gardener who has a small crop or a large freezer.
Tubers cannot be immediately frozen. After the curing process, peel, cut and boil the sweet potatoes until they are fork tender. Freeze either cut or mashed sweet potatoes immediately after boiling. This is great for sweet potato fries or individually portioned baby food.
Frequently Asked Questions
Q: Can you eat sweet potatoes right after harvest?
A: While the tubers are edible, they are not yet very sweet. Wait at least 10 days for the sugars to develop before eating for optimal taste.
Q: How many sweet potatoes do you get from one plant?
A: This depends a lot on growing conditions. Many healthy plants produce 8 sweet potatoes per plant, but the size of the tuber will depend on the health of the soil, and the length of time in the ground.