Gardening & Landscaping Stack Exchange is a question and answer site for gardeners and landscapers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

Something that I've heard quite regularly is that when you plant your tomatoes, you should put an aspirin under each plant. Apparently salicylic acid both increases the number of blooms and strengthens the plant's immune system.

I've been unable to find any references for studies done on this. Nor have I found it discussed on some of the sites or in books that I find more trustworthy.

So, does anyone know of any good references for this?
Does anyone have an explanation of why aspirin in particular helps tomatoes?

  • Some website references: 1, 2, 3, 4, 5, etc...
share|improve this question
Sounds like it could be an old wives' tale. However I think it could be a good experiment for a school science fair project! Having judged plenty, having an original idea like this counts for a lot (and no more Vitamin C experiments, thank you!) – winwaed Jan 23 '12 at 14:05
up vote 7 down vote accepted

Salicylic acid is a phytohormone (plant hormone). It was originally extracted from willow bark. It mediates systemic acquired resistance, the reaction of a plant as a whole to a localized pathogen attack.

It's been shown to be effective when sprayed on some plants against some pathogens. There's a book on its role as a plant hormone. I'd get it from inter-library loan - it's a $200 book!

Sounds promising. We had some late blight this year that I would have tried it on to (hopefully) slow the spread.

share|improve this answer
Thanks Ed. The references you and @CuriousGuy provided show that as a plant hormone, Salicylic acid is important and can have an effect applied to the leaves or roots. However, it's still not clear whether it is worthwhile in actual garden situations - there seem to be no references for field trials. – Simon Feb 18 '12 at 23:24

A few other references on Salicylic Acid treatment (in plants). If you have a local state university most of these journals should be available as walk-in. Also, if you call the librarian you can often get access with a good story.

I hope this helps.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.