Tuesday I bought 9 Beauregard sweet potato plants from a local store. I haven't grown sweet potatoes in a very long time. This afternoon, I started digging the bed for the plants. Sweet potatoes like a hot sunny place. An ideal spot was already taken in my garden.
The plants in the ideal spot that I picked are hundreds of double daylilies and a lot of peppermint. I dug all the daylilies and mint up with a garden fork. I had a heaping wheelbarrow load of daylilies to take off. The mint that I removed filled a laundry basket. Later I dried some of the mint. The rest went into the compost.
The bed ended up being 9 feet long and 8 feet across. Below is a picture of the bed.
After that I used a garden hoe to form three high ridges in the soil. Ridges are a traditional way to plant sweet potatoes. The piled up dirt provides the roots loose soil in which to develop and perhaps the potatoes won't be too hard to dig up later. Piling the dirt in tall ridges sort of encourages that plants to "put the potatoes there," but that doesn't mean the plants will cooperate.
At this point, a person can plant the sweet potato plants in the top of the ridges spaced at around 12-18 inches apart. Then keep the area weeded until the vines shade out weeds. Do not over-water.
Instead of planting at this point, I cover sweet potato beds with black plastic. This time I used black-lined clear plastic. I use black plastic for: 1. its heat absorbing properties, 2. to keep the weeds down, and 3. to keep the ridges from being compacted from too much rain and from me trying to weed the area.
I placed the plastic over the bed and secured the edges. After that, I planted the 9 plants, 3 per ridge. I slipped the water hose into some of the holes and watered the area just to get it damp. I'll water the plants only until they are established. Sweet potatoes like hot dry weather and will not need much water. After all that, I tightened the plastic and secured the edges with brick.
Below is photo of finished sweet potato bed.
When I planted the sweet potatoes, I sprayed the plants and the hole with water mixed with liquid kelp that I buy from Gardens Alive. The little hand pump shown in the image is an invaluable tool for the small garden. I filled it 3 times today to spray the liquid kelp/water mixture on all of the plants in the garden as well as all of the other plants that I transplanted today.
Edited to add: Harvest sweet potatoes before the vines are damaged by frost. Carefully dig with a garden fork while trying not to damage the potatoes. Lay the sweet potatoes on the ground for a few hours to cure. Then cure them in an airy warm (85-90 F.) place for 10-15 days. After that, store sweet potatoes in an area that is around 50F. (but not less than 50F.) with moderately high (75-80%) humidity.