Sweet Potato Storage: storing sweet potatoes for planting next year

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how to store sweet potatoes for long term storage

When it comes to growing sweet potatoes, proper storage techniques play a crucial role in preserving the quality and ensuring a successful next growing season. Storing sweet potatoes correctly can help maintain their freshness, prevent rotting or sprouting, and provide you with healthy tubers for future planting.

This article is one of several targeted towards building food security for your family, and a large part of food security is putting food away for future times. When it comes to sweet potatoes, the best variety for storage is the variety you have an excess of right now or have expectations of having it soon. Let’s break this topic down.

Understanding the Importance of Sweet Potato Storage:

Before delving into the storage techniques, it’s essential to understand why proper sweet potato storage matters. Storing sweet potatoes optimally prolongs their shelf life, preserves their nutritional value, and allows you to save viable tubers for replanting in the next growing season. This means you can enjoy a bountiful harvest year after year while maintaining the quality of your sweet potatoes.

The key aspect of this process is to store what you have grown, and that you intend to plant and grow more than your immediate needs to allow subsequent storage seasons.

sprouted sweet potatoes for planting

If you need information on growing sweet potato we have several articles dedicated to this vegetable, from growing in raised garden beds, to companion planting, growing in clay soil, and also in shade.

These articles have been written to share our experiences in that topic and we highlight the issues that can surface in each situation.

Preparing Sweet Potatoes for Storage:

To ensure successful storage, proper preparation is key. Begin by harvesting sweet potatoes when the foliage starts to yellow and die back. Gently dig them up, taking care not to damage the tubers.

We have found that the depth of the sweet potato crop is largely governed by the fertility of the garden and the hardness of the ground. This article explains the root system of the sweet potato and how you can make life easier with good soil.

After harvest, carefully brush off excess soil and remove any damaged or bruised sweet potatoes. This preparation step sets the foundation for effective storage. This is also a good time to check for any underground insect or grub activity.

underground insects can attack sweet potatoes
Damage from underground insect or grub attack

If the tuber looks intact, we can consider it for storage, but with care. Store any like this separately, well away from the best tubers.

Personally, we wash the tubers with a pretty strong hose to remove the soil. The potatoes are then left to dry, ready for the next step.

Curing Sweet Potatoes:

Curing is a critical process that allows sweet potatoes to develop a thicker skin, heal minor wounds, and convert starches into sugars. Place the harvested sweet potatoes in a warm, well-ventilated area with a temperature around 80-85°F (27-29°C) and a relative humidity of 85-90%.

intact skin of a sweet potato
This is common for us where the sweet potato grows amongst other roots, leaving hollows like this.

Maintain these conditions for approximately 10-14 days, turning the sweet potatoes occasionally to ensure even curing. This step significantly enhances the flavor and shelf life of the tubers.

Your climate will dictate your timing and temperatures. We keep a close watch for insect activity near the potatoes as they cure. This is critical if you are relying on this process for next year’s planting. The insects are opportunistic and can be managed.

Selecting the Right Storage Location:

Choosing an appropriate storage location is vital to ensure the longevity of your sweet potatoes. Ideally, opt for a cool, dark, and well-ventilated area with a temperature range between 55-60°F (13-16°C). Avoid storing sweet potatoes in the refrigerator, as the cold temperature can adversely affect their flavor and texture.

Basements, root cellars, or cool closets are great options for maintaining the desired storage conditions. Be careful of overly humid locations and poor airflow. The light level should be as dark as possible.

Storage Containers and Arrangement:

Suitable containers for sweet potato storage

To prevent moisture buildup and maintain proper airflow, store sweet potatoes in well-ventilated containers. Opt for wooden crates, mesh bags, or cardboard boxes that allow air circulation while protecting the tubers from direct light.

Avoid using plastic bags or airtight containers as they can trap moisture and promote rotting. These types of containers are tempting however they can promote sweating and then the root rot can set in. This can be disastrous in some situations.

Organizing sweet potatoes for optimal airflow

When arranging the sweet potatoes, avoid overcrowding to allow sufficient air movement around each tuber. We suggest several layers that are separated to avoid blocking any airflow. Metal oven racks are great for this.

Controlling Humidity Levels:

Humidity control is crucial during sweet potato storage. High humidity can lead to excess moisture and rot, while low humidity can cause tubers to become dehydrated and shriveled. To maintain an optimal humidity level, you can place a shallow tray of water near the storage area. This will help create a slightly humid environment without directly affecting the sweet potatoes.

Your storage location will be different to many others so be mindful of the potential risk that humidity presents. We are fortunate to live in the wet tropics of NE Australia where the sweet potato thrives. The storage season (our winter) generally has a good humidity level so storing the sweet potato tubers is not that challenging.

Even so, we still keep most of our crop in the ground where we can pick as needed. Cold climates may not have this luxury, and it is not a simple risk-free practice because some patches of garden do have grubs and insects that reside in the soil and find our potatoes very tasty. The odd tuber is found with worms in the flesh.

Checking and Sorting:

Regularly inspect your stored sweet potatoes to identify any signs of rotting or sprouting. Remove any spoiled tubers immediately to prevent the spread of decay.

scarring on sweet potato skin
Letting the sweet potato skin cure can help with skin damage like this

Additionally, sort through the sweet potatoes and use the larger, healthier ones for replanting in the next growing season, reserving smaller or damaged ones for consumption. This is important for long-term food security. To do the opposite is to plant second grade or poor-quality seed potatoes and hope for a good crop.

The truth of this practice is that every crop following from that choice will potentially deliver lower quality harvests with each subsequent planting… finally ending in crop failure.

Extended Storage Options:

If you live in a region with mild winters, you can store sweet potatoes in the ground by mulching the plants with straw or leaves. This method provides insulation and protection against frost while allowing easy access to the tubers throughout the winter season.

sweet potatoes growing under mulch
A nest of sweet potatoes at the surface. This location is under the edge of a mango tree.

As we mentioned above, this is not a fool-prove method, but should be considered if your soil holds few or no problematic animals or insects. We suggest trialing with just a few tubers first up and monitor the process. If successful, then expand the storage and perfect the method for where you live.

Another option is to store sweet potatoes in sawdust or sand-filled containers, ensuring they are completely covered to maintain a controlled storage environment. This is a good method but take care of moisture levels in the sand or sawdust. The sawdust can hold fungal spores that can create issues given the opportunity.

Conclusion:

Proper storage techniques are paramount when it comes to ensuring the success of your sweet potato harvest and replanting efforts. By following appropriate guidelines and incorporating optimal storage practices, you can preserve the quality and extend the shelf life of your sweet potatoes, allowing for a bountiful harvest in the next growing season.

Remember to implement the discussed methods, adapt them to your specific conditions, and enjoy the rewards of a thriving sweet potato garden year after year. Food security does not need to be difficult if we approach things in an organized manner.

Article by Tim Blanch for TheTropicalHomestead.com. He is a qualified Permaculture designer.