Salicylic acid contained in aspirin may boost the growth rate of plants. Research has also found that aspirin helps to trigger the natural defenses of plants against microbial and insect attacks. This is because salicylic acid is credited with triggering systemic acquired resistance in plants.
Tests conducted at the University of Rhode Island in 2013 found that using a solution of water and aspirin on plants increased their production and quality. The vegetables were grown in compost-amended soil using drip irrigation. For the test, each bed of plants was sprayed with the solution, which contained 1.5 aspirin tablets for every two gallons of water once every three weeks. The tests found that the plants sprayed with the aspirin and water solution were healthier than those that were treated with a commercial bio stimulant.