Use black oil sunflower seeds to reduce spillage.

How to get rid of grackles at feeders. There are 4 effective ways you can get rid of grackles, blackbirds, and starlings at your feeder: Offer massive amounts of cheap food that grackles can’t resist, such as corn, positioned at least 15 feet away (4.5m) from your other bird. Don’t use tray feeders or feeders with platforms that allow grackles to land.

Change the types of feeders you use. Although you may be able to keep grackles from raiding your feeders, they may also be eating all the spilled seed on the ground. Top 3 excellent grackle proof bird feeders you need to know.

Change what foods you feed birds.