Good and Bad Plants

 We constantly make distinctions between good and bad plants, especially as they are good or bad for us.  The distinction has a long history.  The book of Genesis in the Bible has God warn Adam, as he's driven out of Paradise, that from now on he's going to have to work growing and harvesting grain, and that bad plants (like thorns and thistles) were going to get into his fields, causing trouble.

We call plants that are growing where we don't want them weeds.  But the distinction between good plants and weeds is a tricky one.  Any plant growing where we don't want it may be labeled a weed, and individual plants may be good or bad in different contexts.  Dandelions, all lawn maintenance firms agree, are a weed that must be eradicated, but they do make one's lawn brightly yellow and cheery after a long winter, plus you can make wine from dandelions (and eat the greens if it's been a long and hungry winter).  For years American cities planted callary pear trees for springtime flowers along the streets, but now they've been declared a noxious weed.  Brush and high grass are generally considered weeds, but they provide cover for songbirds.  Native plants may be considered good and non-native plants (that would cover dandelions) as weeds, but that would dump many of our crop plants into the weed category.

Medieval thinkers understood the difficulty of good and bad as unambiguous labels for plants.  (Interestingly, Latin has no word for "weed," so one could speak of "bad plants" but not "weeds" in the English language sense.)  For example, stinging nettles were definitely bad plants for farmers, who tried to eradicate them, but medieval herbalists used them to make various medicinal concoctions.  Nettles (or at least the ground-up stems) were considered good for colic and for coughs.

The use of medicinal herbs was complicated in the early Middle Ages by lingering fears about paganism, which was usually tied to magic.  So someone grinding up and sprinkling herbs around could either be a wise doctor or a dangerous pagan.  Women especially were looked at with suspicion if they seemed to know too much herbal lore.

The distinction between good and bad plants also had gradations.  It is clear that different kinds of grain were rated more or less highly.  Of the major crop plants, wheat was always described as best, followed by rye, followed by barley, followed by oats, designated as coarse peasant food.  Interestingly, however, dark bread made with at least some rye was eaten by everybody in much of France and Germany, including the elite, and in some places, like Scotland, everybody ate oat bread.

In all of this the assumption was that plants were good if they were good for humans.  Thorns and thistles, against which God warned Adam, were for medieval people the markers of wild places, uninhabited or at best the home of bandits and untamed beasts. Medieval monks sought out wild places to establish monasteries far from worldly distraction, but their first thought was to get rid of all the bad plants and replace them with good crops.

Humans have always had a hard time with wilderness.

Much of the information in this post is treated at greater length by Paolo Squatriti, in the volume The Oxford Handbook of the Roman World (ed. Effros and Moreira, 2020).

© C. Dale Brittain 2024

For more on medieval food crops and so much more, see my ebook, Positively Medieval:  Life and Society in the Middle Ages, available from Amazon and other ebook platforms.  Also available in paperback.