Simple, ordinary aspirin (acetylsalicylic acid), known to assist with addressing a long list of human ailments, has also shown to be beneficial to outdoor gardens as well as houseplants. Plants increase their own production of salicylic acid to heal themselves when threatened by disease, even emitting a salicylic gas to warn other plants that dangerous insects are around. Add aspirin to water and feed it to your plants to boost disease and pest resistance and form stronger immune systems.
Use inexpensive, uncoated, regular-strength aspirin tablets. Grind well using a mortar and pestle or the back of a spoon. The standard recipe is one aspirin per 1 gallon of water. Shake or stir to mix well and apply with a standard spray bottle. If you like add two or three drops of liquid dishwashing soap to the water to help solution stick to your plants.
Add a crushed aspirin to vase water before placing your display or bouquet in it. Cut flowers react as if sliced stems are a wound. Aspirin counteracts the wilting and aging reaction, helping floral displays last longer. You can also spray potted houseplants every few weeks to improve growth and combat common pest problems such as aphids.
Spray vegetable beds every three weeks with a solution of 2 gallons of water to 1.5 ground aspirin, which can contribute to healthier, larger vegetables. Increase seed germination by spraying seed beds with aspirin water, assisting in fending off bacteria and viruses. The aspirin solution can also be applied to garden compost to prevent fungus and bacteria.
Stick to the basic recommended recipe and space out applications. Using too much aspirin too often will burn plants.