Most bearded iris varieties are not 100% deer resistant. However, they are amongst the most deer-resistant plants you can grow, according to the New Jersey Agricultural Experiment Station or NJAES at Rutgers University. Rutgers has researched deer resistance extensively, and after thorough investigation it has given bearded irises a rating of ‘Rarely Damaged’. This is the most resistant of the four categories and applies to most types of bearded iris. So while bearded irises may be browsed when there is nothing else for deer to eat, this rarely happens.