THE HOT WALL
The north boundary wall of the Nelson Garden is an integral part of the late 18th century garden of No.18 Monnow Street (Nelson Garden) and is one of its most unusual and interesting features. The brick wall is contemporary with the creation of the garden and survives in its entirety. It has been restored as part of the programme of restoration grant-aided by the Heritage Lottery Fund.
The wall is unlike the walls on the remaining three sides of the garden in that it is what is termed a ‘hot wall’: it was heated by hot air in horizontal flues within the wall. Hot air was provided by a fire in an oven, which survives in part, at the foot of the outer side of the wall. After wending its way through the flues, the air escaped from a hole in the top of the wall.
The purpose of this system of heating was to bring forward the ripening of wall fruit, extend the growing season and protect fruit blossom from frosts.
Although hot walls were commonly built in kitchen gardens in the 18th century few have survived. The Nelson Garden wall is therefore of significant cultural and historic value as a rare example in Wales of a hot wall that survives more or less intact.
The history of hot walls begins in this country in the 18th century. They are usually found in walled kitchen gardens, where fruit was grown against the walls. The earliest known example was at Belvoir Castle, Rutland, before 1718. By the middle of the 18th century they were well established.