short, stubby roots growing on a tomato plant stem

​​​​Adventitious roots on a tomato stem

Updated: June 16, 2021

Bumps and growths or adventitious roots on tomato stems

growths or adventitious roots on tomato stem
Adventitious or aerial roots on tomato stem

Tomato plants, particularly heirloom varieties, and tomatillos may produce small growths with short, fleshy, bristles. These are adventitious roots or aerial roots that would grow into normal roots if placed in contact with the soil. But in many cases, they can appear higher up on the stem.

The degree to which a gardener will see this is determined by cultivar, weather conditions, and culture.

the beginning of adventitious roots growing on a stem
Adventitious roots forming on tomatillo stem

Adventitious roots are normal bumps and swellings on stems

Small knobs, swellings, or bumps on stems are usually harmless and caused by plant genetics (natural growth) or stressors in the environment. Pepper, tomato, and rosemary plants often exhibit such growths. No action needs to be taken.

 

adventitious roots closeup
Closeup of adventitious roots on an old stem of bluemist shrub. Photo: Ria Malloy, UME