Limewash: An Old Practice and a Good One

Historically, plantation landscapes were limewashed or “whitewashed.” The reasons behind this centuries old practice are both aesthetic and practical. Limewashed structures brighten up the surroundings and look great because it glows due to innumerable small crystals. But did you know that limewash is a fire retardant, antiseptic, antifungal, odorless and non-allergic paint?

If buildings are not painted, limewash can slow deterioration of wood and brick due to weather and allow rainwater to run down the outside walls without soaking in. It helps buildings "breathe" by allowing trapped moisture to pass out of the building, reducing mildew and rotting of structural timbers. Limewash can eliminate mosquito larvae, reduce odors where animals are kept and when painted on roofs it reduces inside temperatures up to 10 degrees. It also sweetens the soil around a building. Limewash on iron or other metals prevents rust. Painted in tree trunks, limewash prevents disease, sunburn or frost injury.

Cane River Creole National Historical Park plans to re-establish this former historical and cultural landscape practice and limewash mature trees at Oakland and Magnolia Plantations. Evidence indicates that the practice of limewashing the bases of trees' trunks occurred regularly into and throughout the early 20^th century at both plantations.

Most limewash ingredients were readily available on the plantation. During the colonial period, people got their lime from local deposits in Winn and Bienville parishes where limestone occurred naturally as cap rock protecting salt domes from the environment. Also, lime could be burned from local shell deposits. When limestone is burned, it drives out the water creating calcium oxide; when water is mixed with it, calcium hydroxide is produced which becomes limestone again when it dries. Other ingredients were known by trial and error to bond limewash together and make it more waterproof, including molasses, milk solids (casein), oils, pine rosin, and tallow. In our area, molasses and table salt were often used. Salt was often added to exterior limewash to make it more durable and dry slower, producing a better finish. Salt probably came from local salt works. Limewash could also be colored if the opaque white lime color was not desirable.

The limewash formula for the project to limewash to trees historically known to have been historically treated at Oakland and Magnolia Plantations shall consist of hydrated lime and water, as recommended by the National Park Service (NPS) National Center for Preservation Technology and Training (NCPTT). The park limewashing project will occur in stages that will result in a limewash coating to the lower trunk of each tree that was present during the historic period.

Source: Marcy Frantom