A bird feeder placed at or near ground level is at the most natural feeding height for cardinals. According to the Cornell Lab of Ornithology and the National Audubon Society, cardinals are ground foragers. They can be found, in pairs or flocks, searching the ground for insects and seeds. A ground feeder is also likely to attract other ground feeders, such as dark-eyed juncos, white-throated sparrows, tufted titmice, towhees and goldfinches.
Ground feeders offer birds no protection from predators such as cats. Placing the feeder about 10 to 15 feet away from any shrubs or cover will help prevent sneak attacks. Don't place the feeder farther away, however, or cardinals become vulnerable to aerial predators. Ground feeders are usually platform feeders, which are preferred by cardinals. Platform feeders offer little protection for the seeds from the elements or from other animals, such as squirrels and raccoons, and are more prone to spread diseases than other types of feeders.
A feeder placed at shrub height, or 5 to 6 feet high, offers more protection for cardinals from predators such as cats. It also protects the bird feeder from squirrels, raccoons and other species. According to Cornell Lab of Ornithology, cardinals will visit almost any backyard feeder except for tube feeders. If you decide to place the feeder higher, expect to see fewer birds. According to a 2009 study by Laura M. Opitz for Birdsleuth Reports, bird feeders placed at 5 feet or higher will see less activity than feeders placed on the ground.
No matter how high you put your feeder, located it away from wind, preferably on the east or southeast side of the house. Cardinals love sunflower seeds, either striped or black oil, but will also eat peanut kernels, white proso millet and safflower seeds. Cardinals also like fruit and nectar (oriole) feeders. Add pieces of pomegranate, grapes, apples or other fruit to your platform feeder or in a separate feeder to lure more cardinals to your yard. Throw out any fruit that gets moldy.