When we think of roots, most of us think of pale, fibrous, slimy-looking tubes whose only purpose is sucking water out of soil. If we’re gardeners or farmers, we also think of roots as food. But roots do much more than siphon water and provide food—they’re the cornerstone of plant function. And in many ways they are more fascinating than the leaves, blossoms, and fruits they help produce.
Of course, roots’ main job is to deliver water and minerals. They are, in essence, the starting point of the plant’s vascular system. But roots also serve as a plant’s anchor; act as a repository for carbohydrates, sugars, and proteins; and ensure the plant’s survival during the long cold winter months.
Often a root system occupies a larger space than the plant it supports, comprising up to one-third a plant’s overall mass, it’s total length reaching into the hundreds of miles! There are, generally speaking, two types of root systems: tap and diffuse. Tap systems are those with many smaller rootlets branching off a single, main root. (Think carrots and dandelions.) Diffuse systems are comprised of many thin roots which draw from even thinner and smaller rootlets (corn and rye).
Root health is in large part determined by soil quality. Roots require biologically-rich, well-aerated soils. Excessively waterlogged or compacted soils, or soils that are otherwise oxygen deficient, can lead to shallow root growth.
Roots also have an intriguing relationship with microorganisms. Rhizobium, a well-known soil bacteria, converts atmospheric nitrogen into an organic nitrogenous compound that acts as a fertilizer. These bacterial clusters present themselves as nodules on roots.
Some more fun root facts:
- Roots grow from their tips, but only in warm weather.
- By splitting rocks into smaller pieces, roots contribute to soil-creation.
- Each root is covered with tiny hairs through which water and minerals are absorbed
- The roots of a South African wild fig tree can exceed depths of 390 feet!
- Eighty percent of all plant disorders are caused by root/soil problems.