If you navigate by moss, you will get lost
Once a week, the "Checking the Myth" column deals with famous historical distortions, why they were created, and how they affect us to this day. This week: Does moss grow in a specific direction, thereby allowing for spatial orientation? Not in the middle of the forest.
Shahar Lotan is an economic and strategic researcher, a reserve intelligence officer, and a history and geography enthusiast who writes a blog about fascinating and forgotten events and figures. In this column, he exposes famous historical distortions, why they were created, and how they affect us to this day.
A common rule of thumb that appears quite often in survival movies and nature programs states that if you get lost in the forest, look for green moss on tree trunks or rocks, because it always grows on the side facing north (or south, depending on which hemisphere you are in).
It sounds simple and elegant, as if nature itself leaves us clear signposts, but the truth is that it is a myth, and if you rely on this small plant to find your way out, you might find yourself walking in endless circles.
Let's start with basic biology. Moss is a primitive plant lacking real roots, so it absorbs water directly from the air and its immediate environment. To thrive, it mainly needs high humidity and little direct light. Therefore, it is not as common in Israel as it is in Europe, and it is in these conditions that the roots of the myth were born.
Like many misconceptions regarding the natural world, this is an overgeneralization of a partial fact. It is true that in the Northern Hemisphere, the sun is in the southern part of the sky for most of the day, so the northern side of trees and inanimate objects receives fewer direct sun rays and tends to be cooler and more humid. At the edge of an open field or in an urban garden, it is very likely that the moss will indeed prefer the northern side.
It is important to emphasize that even under such conditions, it is a matter of probability and not an absolute rule. Trees that lean to one side, buildings that cast shadows on each other, a dynamic wind regime, and even animal activity can change the moisture distribution in a specific area. The result is that moss may appear on several sides simultaneously, with varying intensities, so that even when a general tendency exists, it is far from being a consistent and reliable navigation tool.
And if you have ever hiked in rainy mountain ranges or deep, shaded wadis, you know that the microclimate in the area is what determines everything. Even deep inside the forest, where one truly gets lost, the tree canopy blocks most of the sunlight, and the humidity changes according to altitude, water flow, and the shape of the terrain. Accordingly, the moss may grow in different places on the trunk or rock, without any reliable connection to direction. Following it is sometimes nothing more than a trick of our brain, which looks for patterns even where they do not really exist.
If so, how did they find north in ancient times? They simply looked up at the sky. The North Star, Polaris, which is located almost exactly above the Earth's axis of rotation, served as an anchor for night navigation in the Northern Hemisphere. During the day, one could use shadows, as a stick stuck in the ground marked the movement of the sun and the general direction in which it was moving.
But even these methods do not help in the heart of a dense forest. Therefore, the next time you go out into isolated nature, you are welcome to enjoy the moss as an ancient, fascinating, and important plant for the ecosystem - but to know where north is, it is better to simply rely on a compass.
