Unlike potatoes (which are tubers), sweet potatoes are roots and, as such, are propagated via a slip. What is a sweet potato slip? A slip from a sweet potato is simply a sweet potato sprout. Sounds simple enough, but how do you get sweet potato slips? If you’re interested in sweet potato slip growing read on to learn more.
What is a Sweet Potato Slip?
Sweet potatoes are members of the morning glory or Convolvulaceae family. They are grown not only for their edible, nutrient rich roots but for their trailing vines and colorful blooms. Given that sweet potatoes are from a different family than regular spuds, it’s no wonder that propagation is different.
Regular potatoes are grown from ‘seed’ potatoes but sweet potatoes (Ipomoea batatas) are grown from sweet potato sprouts or slips. Sweet potato slip growing is really just coaxing a rooted sprout from a mature sweet potato. Slips can be purchased, or you can learn how to get sweet potato slips to grow yourself.
How to Make Sweet Potato Slips
Sweet potato slips can be started in two ways, in water or in dirt. Of course, both propagation methods work, but starting a slip from a sweet potato in dirt is the more rapid method. If using a sweet potato from the store, buy an organic one which is less likely to have been treated.
A single sweet potato can grow around 15 slips or more which, in turn, equals 15 plants that will produce about 60 sweet potatoes.
The first method of starting in water is a bit reminiscent of starting an avocado from a pit. Submerge half a sweet potato in water, root end in the water. Use toothpicks to keep the entire potato from becoming submerged.
Not sure which end is the root end? The rooting end will taper and have small roots and the other end of the potato will be larger with more ends. Roots will form in the submerged rooting end and sprouts will appear in the top end.
Place the sweet potato in water on a germination mat or atop the refrigerator. Keep an eye on the water and replenish as needed. In a few weeks or so you should see the beginnings of roots. A week or so from then, sprouts should begin to form.
The other method of starting slips is to lay a sweet potato lengthwise on a bed of seedless soil mix or potting soil and bury half the sweet potato in the medium. Keep the soil moist and in a warm place or atop a germination mat.
Sweet Potato Slip Growing
In either case, once sprouts are 5 to 6 inches long (13-15 cm.), it is time to move onto the next step. Gently remove the sprouts from the sweet potato by twisting or cutting off. Remove the lower leaves from the sprout and place the partially denuded sprout in water in a warm area with plenty of sunlight or with a grow light. Keep the water replenished as needed.
Once the roots are 4 inches (10 cm.) long, it is time to plant them. Plant your slips 12-18 inches (30-46 cm.) apart and 4 inches (10 cm.) deep. Water the plants in well and feed them with a fertilizer that is rich in phosphorous.
Once you harvest your sweet potatoes, remember to save a couple to start slips for the next season’s crop.