Does Talking to Plants Help Them Grow?
There is no strong scientific evidence that talking to plants helps them grow. Some studies suggest vibrations or CO2 from breathing might have minor effects, but results are inconsistent and effects are small. The real benefit may be that people who talk to their plants pay more attention to their care. Plants do not 'hear' or understand speech.
Key Takeaways
- Plants lack ears, brains, and any mechanism to process speech.
- Music studies are similarly inconclusive - any effects are likely from vibrations, not musical quality.
- The MythBusters show tested this and found inconclusive results.
Explanation
Plants lack ears, brains, and any mechanism to process speech. They cannot understand words or respond to conversations. Any effect from talking would have to come from physical aspects of speech - vibrations, CO2, or moisture in breath - not the communication itself.
Some studies have found that sound vibrations can influence plant growth, but results vary widely. The Royal Horticultural Society conducted an experiment finding plants grew slightly more when exposed to human voices, but the study had limitations. Other controlled experiments show no effect. The evidence is not strong or consistent.
The most likely explanation for 'plants growing better when talked to' is that attentive plant owners notice problems earlier, water more consistently, and provide better overall care. Talking to plants may simply be a marker of attentive caregiving rather than the cause of growth.
Plants do respond to mechanical stimulation through a process called thigmomorphogenesis. Wind, touch, and vibrations can trigger changes in growth patterns, often making stems shorter and thicker. This is well-documented science. However, the vibrations from human speech are far weaker than wind or physical touch. A normal speaking voice produces sound pressure levels of about 60-70 decibels at close range, which translates to minuscule physical force on plant tissue.
The CO2 argument is sometimes raised because plants use carbon dioxide for photosynthesis. While exhaled human breath contains about 4% CO2 (compared to 0.04% in ambient air), the volume of gas from talking or breathing near a plant is tiny. Outdoor atmospheric CO2 already provides far more than brief conversations could add. For meaningful CO2 enrichment, commercial greenhouses pump in gas to reach 800-1,200 ppm, levels that would require constant human presence to approach even slightly.
Things to Know
- Music studies are similarly inconclusive - any effects are likely from vibrations, not musical quality.
- The MythBusters show tested this and found inconclusive results.
- CO2 from breathing near plants is far less than needed to significantly boost growth.
- Some researchers at the University of Western Australia found that plant roots grew toward the sound of running water at 220 Hz, suggesting plants may detect specific vibrations relevant to survival even without hearing organs.