Ancient Soil Amendments: Chaff

This is the third in a series of blogs, about ancient soil amendments used in the garden. Each blog will discuss a common and specific type of soil amendment used in the garden, along with documentation for its use, as well as occasionally discussing why a particular soil amendment was chosen, or its relation to modern gardening practices. The original blogs, along with other gardening related blogs, can be found here.

When discussing chaff in relation to soil amendments, it is important to understand what is meant. Chaff is an old word – from Old English ceaf, and in every definition it refers to the removed dry husks or shells of grains through the process of threshing and winnowing.

There is a detailed explanation in the Geoponika of which types of chaff are best to use in soil building from Varro, which mentions bean, barley and wheat husks (p88, Geoponika, trans. A. Dalby) used to help offset salty soil. This is interesting because Varro included bean husk as a type of chaff, where as other Cato separates the two.

Says Didymos in the same chapter (p89), chaff is okay for roots, but harmful to all manner of fruit, shoots, leaves and green vegetables (whose leaves it pierces). He warns to not place it upwind of farm buildings or pleasure gardens as well for it can cause eye-loss.

Cato talks of making a compost which includes straw, bean stalks and husks and “chaff” in Chapter 37, most likely meaning in this case, specifically grain chaff.

Of course, to use chaff as a soil additive straight would likely have been uncommon. Florentinus mentions ash from chaff in manure, but most other mentions within the Geoponika of chaff use it as a bedding for animals, feed for them, or storage substance (for a variety of foods including grapes and onions). The 15th century play Mankind shares the following proverb: “corn servit bredibus, chaffe horsibus, straw firybusque,” reminding us that chaff was supposed to be used as horse-feed.

Among other uses, Hamerow, Hollevoet and Vince (2016) discussed the use of chaff in Anglo-Saxon England to temper pottery. In Frederic Weaver’s book of Somerset Wills from the 14th and 15th centuries there are three instances of chaff-stuffed beds. In Medieval Merchant Ventures: Collected Studies, EM Carus-Wilson mentions a chaff-stuffed pillow. This practice continued into the 19th century, when the steps to fill the beds were outlined, and such beds were considered superior to straight straw. Finally chaff is even found in thatch and daub from medieval buildings (p43, Food in Medieval England: Diet and Nutrition).

Obviously chaff was used for so many other things, using it as a soil additive would only have been preferable if it was necessary – for instance, to help salty soil – or if the chaff was no longer useful for any other thing.