Corn (Zea) is ripe when silks are brown and dry on top but still yellow just under the husk. Watch for the silks to change color from greenish yellow to brown as the ear of corn matures. You may also be able to determine ripeness by feel. Many gardeners check how filled-out the cobs feel before harvesting, but if you grow different varieties, those that have thin cobs may seem as though they are still filling out. Knowing the number of days to maturity of a variety helps (find the dates on seed packets and in seed catalogs), but keep in mind that the growth rates vary in different climates. Some gardeners peel back the husks to look at the developing kernels. Avoid peeling back any more husks than you must, because the act invites corn earworms, raccoons, and some birds to feed on your corn.