95-100 days. Once only commercially available, this type of popping corn is now available to the home gardener! Robust Pop 400MR produces large, round popped kernels that are sturdy enough to hold a coating and stay in one piece, unlike the more common ‘butterfly’-shaped popcorn. This is also the type of popcorn found in the popular Cracker Jacks® box. Grow popcorn in your backyard to make kettle corn, caramel corn, popcorn balls, or to top with melted chocolate or cheddar seasoning. Grow just like other corn varieties.