How to Grow Your Own Organic Sweet Potato Slips

Sweet potatoes are sometimes called yams, but the two are different plants.

Slips, the vegetative transplants used to propagate sweet potatoes, are available from nurseries and other suppliers. However, growers have the option of producing their own organic slips from seed stock. Buying certified, organic seed stock reduces loss due to viruses and allows you to grow sweet potatoes that have a higher overall quality. Gardeners who need a few slips can use a simple windowsill method. Large-scale growers need a more systematic process that produces up to 1,000 slips per cutting.

Things You'll Need

• Certified sweet potato tubers
• Quart canning jar
• Toothpicks
• Garden snips or a sharp knife
• Pint jar
• Rake
• Hoe
• Plastic, black or clear
• Awl or small screwdriver
• 6-inch-deep wooden boxes or plastic containers
• Drain trays
• Drill
• Commercial soil mix

Instructions

The Windowsill Method

1. Wash a glass jar that is wide and deep enough to hold half of a sweet potato tuber's length. A quart canning jar works well.

2. Push three or four toothpicks about 1/2 inch into the sweet potato at equal intervals so that they will suspend it halfway into the jar.

3. Fill the jar with water almost to the top edge and place it on a sunny windowsill that will stay above 50 degrees Fahrenheit in temperature.

4. Check the jar weekly, adding water to maintain the original level. In two to four weeks, the tuber will sprout and begin to form leaves.

5. Use garden snips or a sharp knife to cut the sprouts, or slips, away from the sweet potato when they reach a length of 6 to 8 inches. The tuber will continue to produce additional slips that you can harvest.

6. Place the slips into a pint jar filled with water. They will soon grow roots.

7. Plant the slips in your garden when all danger of frost is past.

The Garden Method

1. Select a site for the plant bed in a well-drained spot and remove all weeds from an area 2 to 4 feet wide by hoeing and/or pulling them by hand.

2. Pre-sprout the sweet potatoes by placing them in a sheltered location for two to three weeks. The temperature should be between 75 and 85 degrees Fahrenheit with 90 percent humidity.

3. Place the pre-sprouted seed potatoes in a single layer in the prepared planting bed when the soil temperature is at least 60 degrees Fahrenheit. Cover them with 2 inches of soil.

4. Use an awl or small screwdriver to perforate black or clear plastic with small holes and cover the bed with it. When the sprouts are 1 inch tall, remove the plastic.

5. Harvest the slips, or sprouts, when they reach a height of 12 to 15 inches. Use garden snips or a sharp knife to separate the sprouts from the sweet potato at a point 1 inch above the soil line, leaving the remainder of the sprout attached to the tuber.

6. Plant the slips in your garden.

The Greenhouse Method

1. Set aside an area in your existing greenhouse or in a room in your home that can be kept at a constant temperature of 75 to 80 degrees Fahrenheit.

2. Build wooden boxes or purchase plastic containers. The containers should be at least 18 inches wide and 6 inches deep.

3. Use a drill to create drainage holes 5 or 6 inches apart in the bottom of the containers.

4. Protect surfaces in your house by placing a drain tray under each box.

5. Place a layer of organic soil mix 1 inch deep into the bottom of the boxes.

6. Lay sweet potato tubers side by side in the box, keeping space between them.

7. Pour soil over the top of the tubers to within 1 inch of the top of the container.

8. Water the soil until it is completely saturated. Keep the soil damp and the air temperature between 75 to 80 degrees Fahrenheit. In two to four weeks, sprouts will be visible.

9. Create slips when the sprouts reach a height of 5 to 6 inches by cutting them away from the sweet potato. Use a sharp knife to cut the sprout at a point 1 inch below the soil line, taking care not to cut into the tuber. Plant the resulting slips in your garden.

Tips & Warnings

• To hold slips for up to 14 days before planting, place several in a 4 1/2-inch pot with organic soil mix and water thoroughly. To plant them, gently separate the individual slips.

• Provide 16 to 20 square feet of planting surface to create slips from one bushel of sweet potato tubers.

• Growing enough slips to plant one acre of sweet potatoes requires 10 to 12 bushels of tubers.

References

• University of Missouri Extension; Growing Sweet Potatoes in Missouri; Lewis W. Jett
• University of Kentucky Cooperative Extension Service; Sweetpotato; John Strang, et al.; December 2010
• Missouri Vegetable Growers Association; Sweet Potatoes; Norman Kilmer; February 2010

Resources

• National Sustainable Agriculture...; Sweetpotato: Organic Production; Katherine L. Adam; March 2011