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.

This is the second 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.

Manure is talked about quite frequently in husbandry and gardening texts of the period. Manure is unique in that it is both a substance you add to the soil as well as a practice you regularly complete. In the modern mind, manure is is synonymous with animal waste. This is not true in medieval texts. Sometimes manure means animal waste, other times it means anything biodegradable.

Medieval authors compare the dung of different animals as well. Cato outlines specifically that you can just spread pigeon dung on your fields, but you should store piles of other animal waste. Geoponika also discusses the benefits that come from different animal wastes. Walter of Henley warns his readers that manure alone will only benefit your soil for two or three years.

Although the practice is documented as post-medieval, the use of manure to heat winter cold frames is one that could easily have been used. There was a Victorian practice where a brick or stone box was combined with fresh, hot manure, giving several weeks of early heat to plants. Eve Otmar of The Colonial Williamsburg Foundation told me you would get about 4-6 weeks extra heat using this method.

This is the first 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.

After several years of gardening in a space, you will notice a steady decrease in how well the garden produces. For the modern gardener this is annoying, but very few of us in the western world live or die based on the production of our garden. During the Middle Ages, without grocery stores and mega-farms, this was a serious issue.

it is generally accepted that you have to add something to the soil to improve soil productivity. Typically this is done either by straight up adding something to the soil (a soil amendment) or by completing a process (a soil improving practice). Both have an important role. If a soil doesn’t have a characteristic or a mineral, it may be faster and more efficient to simply add what is missing. If the soil is merely low or constantly being drained of a mineral it might make more more sense to regularly perform a task, or build in a system, to replenish the soil.

The modern gardener, even the modern farmer, deals with soil decline quite simply – we order soil amendments from our farm supply or hardware store. If our soil lacks nitrogen, we buy a fluid or pellet mix to spread out and and water in. Obviously, our agrarian ancestors could not do this. Before I discuss the ways pre – industrial societies dealt with decreases in soil productivity, it will help to understand how it happens.

One aspect of soil health (which determines productivity) is fertility. According to the Queensland Government, soil fertility decline occurs when nutrients being removed from the soil in harvested products exceed nutrients being added to the soil. These nutrients can be removed in three ways – by growing crops, soil erosion, and leaching. These first two methods – growing crops and soil erosion cause most of the problems.

Growing crops both draws out and adds in nutrients to soil. Some plants (like peas) add soil nutrients like nitrogen to the soil if most of the plant is allowed to grow, die and compost in the space. Others, (like corn), need large amounts of soil nutrients in order to create healthy foods which is difficult to get back. The nutrients are generally pulled out of the soil into plants through their root structures. For example – lead in soil can be removed through growing (and than disposing) sunflowers through a process called phytoremdiation. If you plant too much of one type of plant – or don’t use proper balance, you hurt the soil health.

Erosion is when wind or water is able to remove nutrients, organic matter, clay or the soil itself from a piece of land. It “decreases nutrient bio-availability, root growth, plant fertility, biological productivity, moisture retention, and water filtration of soil, and erosion perpetuates further erosion” (Palmer, 2009). Although we commonly associate this problem with the “Dust Bowl” of American history, erosion happens every day. Stan Buman says soil can – in best case scenarios – only rebuild at a rate of .24 tons per acre. The same report found that the average soil loss in modern farming practices is 5.8 tons per acre. In a best case scenario, with no-tilling, you will still loose about .22 tons per acre, or just slightly less than you can rebuild. These numbers are designed for big farms but the point is clear – with any tilling or turning over at all, you wil loose soil – and also lose nutrients.

Over the following months, I will share some discussions about each of the different soil amendments and soil improvement practices I have found reference to in medieval or pre-medieval texts. Some of these may seem familiar to you as techniques we use in permaculture or modern organic farming, others may be new. Enjoy the reflection on the past – and I hope you generate some ideas on what you can try in your own gardens!