Rhubarb forcers are familiar to English gardeners, but not as much to their cousins here in America. A rhubarb forcer is used to jump start rhubarb in the early spring, when the nights are still cold. Covering the rhubarb shoots when they first emerge will keep them from getting damaged by frost. During the day, the lid is left off to let the plant get some sunlight, but not too much. Depriving the plant of sunlight decreases the photosynthesis, which keeps the rhubarb pale, and also makes it stretch to get more sunlight. The result is a more delicate stalk that has less bitterness than non-forced rhubarb.
For folks who don't grow rhubarb, the shape is a nice piece of garden ornament that speaks to an earlier time.
It's pretty rare to find a studio potter who is making these. They are some of the most labor intensive pieces I make, but also very satisfying. It is a multi-step process that takes 3-4 days to complete the steps. You can find a video on how I make these by visiting the How's it Growing channel on YouTube. These are made from red terra cotta clay that is fired to approximately 1950 degrees F.
#12 Rhubarb Forcer, Red Terra Cotta, Pre-Order
Approximately 12" inside height, 15" to top of lid. Top ouside diameter is approximately 5", bottom outside diameter is approximately 12".