Put your slips in a clear glass jar, drinking glass or dish and place in a warm, sunny spot. Within a few days you should begin to see roots appear at the bottom of the slip. Once the roots are large and established (a bit of guessing is ok here), your slips are ready to plant.
If you want to grow your sweet potato vines as houseplants, find a small container with good drainage and fill it with high quality potting soil until the surface of the soil reaches about an inch below the rim.
Mix a slow release fertilizer into your potting soil. You can do this before you put it into your pot, or after. Whichever you do, make sure to mix thoroughly so that the fertilizer reaches the bottom of the pot.
Make a hole in the center of the soil deep enough so that the roots of your slip will be covered.
Gently put one or two slips into the hole and firm soil around them. You want to make sure that there are no air pockets near the roots.
Water thoroughly. After watering, you may find that the soil has settled, and if it has, you may need to add some more soil.
Put your pot in a sunny spot and keep the soil moist not wet. To check if your plant needs water, stick your finger into the soil up to the second knuckle. If the soil feels dry, add water. If it's moist at your finger tip, wait and try again in a day or two.
If you want to grow sweet potatoes in your garden or in containers, they will need a long and sunny growing season. It takes at least 100–140 days for sweet potatoes to mature, depending on the variety. In some parts of the country, that means you will have to start your sweet potatoes sprouting about six weeks before your last frost date.
If you want to grow sweet potatoes in container gardens, you will need a large container with good drainage and good potting soil with a slow release fertilizer mixed in. Smart Pots are perfect for this, but any large container with drainage will do.
Sweet potatoes like warm weather, so make sure all danger of frost has passed before you plant your slips outside. Also, make sure to harden off your slips before you put them in full sun outside--they will need time to acclimate to the elements or there is a high chance they won’t make it.
Keep your container soil moist, not wet. You can harvest your sweet potatoes at any stage and they will be edible, but depending on the variety will take 100-140 days to fully mature. Make sure to harvest before the first frost.
To get the most flavor from your sweet potatoes and if you want to keep them for any length of time, you will need to cure them in a warm, dry place for ten days to two weeks.