What you’ll need:
- Untreated sweet potatoes
- An open seedling tray or container with drainage holes
- Potting soil
- Compost or bone meal
- Heating mat (optional but recommended)
When to start:
Late February. One sweet potato can produce over a dozen slips in 10 to 12 weeks.
What to do:
Fill your tray with two inches of soil mixed with compost or bone meal for nutrients. Lay the sweet potatoes horizontally on top of the potting mix with an inch between each one. Loosely cover the sweet potatoes with more soil and water thoroughly. If there are already tiny shoots on the sweet potatoes, leave them uncovered.
Place your tray on a heating mat or somewhere warm in your house (e.g. on top of the fridge or a heat vent).
Heat is more important than light at this stage to bring the sweet potatoes out of dormancy. It can take 2 or 3 weeks before slips start growing. Water the sweet potatoes just enough to keep the soil moist but not dripping wet.
Once the slips reach 10-12 inches, break them off at their base and place them in a jar of water in a window. Roots should grow within a week. Your slips are ready for the garden! If the weather isn’t warm enough yet, just pot them up in some loose soil while you wait.
Optional: to get more robust slips you can give them a haircut. When they reach four inches in length, cut them back to 2 inches to increase stem thickness.
Guide to Growing Sweet Potatoes Outside
Once you're ready to plan your slips outside, make sure to read our guide to growing sweet potatoes in Eastern Ontario and cooler climates. It provides step-by-step instructions to ensure a beautiful crop!