Q. Birds love the sunflower seeds in our feeders but we hear they are allelopathic. Is this true? What can we put on the ground underneath in garden?
Yes, sunflower seeds do retard growth of plants and germination of seeds. Also, birds repeatedly scratching the soil and eliminating wastes will stop the growth of grass under a bird feeder. Suggest you either move the feeder around every few weeks or put it where you won’t mind dead grass.