You’ll most often see beets with their greens still attached during the summer and early fall. Roots should be firm, skin smooth, greens crisp and brightly colored. Pick small to medium-sized beets similar in size to ensure even cooking. When you get home, separate the greens from the roots by twisting gently, leaving behind a one- to two-inch stem. Store in a plastic bag, the unwashed beet roots will stay fresh in the refrigerator crisper drawer for a few weeks.