A mixture of crushed red pepper, apple cider vinegar and water is an effective homemade spray to keep birds off plants, as is a mixture of cloves and water. Even simpler, cayenne pepper mixed with water is also effective in keeping birds at bay.
Whole chili peppers can also be mixed with water and left to ferment in the sun for several days. Spray the pepper-infused water on plants and surrounding areas to eliminate bird activity. Other homemade devices to keep birds away include scarecrows, noisemakers such as aluminum cans strung together on a wire or shiny objects such as CDs hung from places the birds like to perch.