How Roots Communicate Underground

By Nina Walsh · October 1, 2026

The Wood Wide Web

Beneath the soil surface, plants communicate through an intricate network of fungal connections known as mycorrhizal networks. These networks link the roots of different plants, allowing them to share nutrients, water, and even warning signals about pests and disease.

Mycorrhizal Networks

Mycorrhizal fungi form symbiotic relationships with plant roots. The fungal hyphae extend far beyond the root zone, acting as extensions of the root system. In return for sugars from photosynthesis, the fungi deliver water and minerals from the soil.

Resource Sharing

Mother trees send carbon to shaded seedlings through fungal networks
Dying trees transfer nutrients to neighbors before death
Legumes share fixed nitrogen with non-legume neighbors
Connected seedlings grow 2-3 times faster than isolated ones

Chemical Signaling

Roots release chemical compounds into the soil that neighboring plants can detect. When attacked by herbivores, some plants release volatile organic compounds through their roots that trigger defensive responses in nearby plants, priming them to produce defensive chemicals before the herbivore reaches them.

Kin Recognition

Plants can distinguish between roots of related individuals and strangers. When growing near kin, plants reduce root competition and share more resources. Near strangers, they compete more aggressively. This suggests a level of social behavior previously thought impossible in plants.

Implications for Gardening

Understanding root communication changes how we think about plant spacing, companion planting, and garden design. Avoid disturbing the fungal network by minimizing tilling. Inoculate new plantings with mycorrhizal fungi to help them connect to existing networks.