Use of Aspirin for Tomatoes


Some gardeners recommend using aspirin when growing tomato. I would like to know whether it is safe. What are the benefits of using aspirin? How much should it be diluted? How often should aspirin be applied?
Thanks so much for your help.


Thank you for contacting the Toronto Master Gardeners with your question regarding Aspirin use when growing tomatoes.  The ability of Aspirin either used to water or spray plants to enhance growth and prevent disease seems to be predicated on Aspirin’s (acetylsalicylic acid) link to salicylic acid that naturally occurs in plants.  Researchers have identified that naturally occurring salicylic acid may help plants to fend off some diseases and resist difficult conditions like heat stress.  However, rigorous research into the use of Aspirin to aid plant growth and disease resistance is lacking, especially outside of laboratory settings.  At this time there is insufficient evidence for the Toronto Master Gardeners to recommend the use of Aspirin in plant cultivation. The links below provide further information regarding the existing research and critique of the available information.

Good cultural practices are the best bet to successfully grow tomatoes.  This starts with choosing quality seeds or transplants, ensuring optimal growing conditions with enough light, water, nutrients and good soil.  Space the plants sufficiently to allow air circulation and discourage pests and diseases.  If your growing space allows, rotate your tomato crop from one area of the garden to another each year to decrease the chance of attack from pests that overwinter in the soil.  Tomatoes are “heavy feeders” and will benefit from nutrients in a “fresh” area of the garden each year and a little organic fertilizer.  Please see the links below for further information on growing tomatoes.