Those sweet potato starts really took off when the weather got warm. Remember that - sweet potatoes like heat!
If you start them early, then keep them where it's warm and give them plenty of water.
I put ours in the ground a couple of a weeks ago along with a few slips purchased from the store. These have stayed much happier than the slips. This is how I'm doing them from now on:
- Cut them in half and submerge in a jar of water with the end sticking out.
- Let it stay where it's bright and warm.
- When they have roots and leaves, plant them.