Collards fall into two groups. Vates and Georgia collards are popular and typical of the loose-leaf type. Champion is a slow-bolting variety selected by the VA Truck Experiment Station. The other type is cabbage-collards. These plants spread wide but stay more compact, eventually forming a loose head of paler green leaves in the center.
Hybrid collards are prolific, grow quickly in cool weather and mature all at once.
Green Glaze, an old collard variety, has dark, shiny leaves that seem to be less attractive to caterpillars. Brassica breeders are attempting to introduce this genetic trait into broccoli and the other more glamorous relatives of collards. How to Grow Both of these hardy greens grow best in cool weather and rich soil, with plenty of moisture. Mulch helps to keep soil cool and moist. Kale is somewhat more cold hardy, and collards are a little more heat tolerant.