The elaborate layering exploited the heat generated by the composting. Ingenious.

As the weather warmed up and we moved toward summer, the main crops were planted — corn, beans, melons, and peanuts. Sweet potato plants were ready for pulling from the hotbed — a structure made of 4 x 3 x 3 boards stationed in a corner of the garden. The bed was made by filling in a 6-inch layer of fresh stable horse manure that was then covered over with a 4-inch layer of dry oak leaves and few twigs of green pine needles. A 4-inch layer of old hay was added and that was topped with a 5-inch layer of clean, dry sand. The bed was then covered with a piece of old blanket or canvas and left to heat up for a few days. When the temperature in the hotbed reached 70˚, specially selected sweet potatoes were inserted into the sand, and the cover replaced. The bed was aired daily, every afternoon when the temperature was at its highest, and sprinkled lightly with warm water during incubation. When the plants reached a height of 5 inches, the bed was left uncovered so that the plants could toughen before setting them in the open ground.
Edna Lewis. The Taste of Country Cooking.

And so for day 2020