Here are seeds of one of the most cold hardy Eucalyptus species, Eucalyptus neglecta. This species has been known to tolerate temperatures below zero, and it is listed as being hardy to zone 7, although the source of these seeds says the parent tree has withstood -14F without any damage, and resprouts from the ground even when frozen back at -25F. Even in areas where Hardy Eucalyptus get killed back by cold, they often resprout from the base. So the ultimate height of this species depends on your climate, as a plant in USDA zone 5 or 6 may survive, but only grow to 4 to 6 feet each year that it is frozen back, whereas a tree in zone 7 or warmer may reach the full height of about 20 to 20 feet. As with most Eucalyptus, this species gets the wonderful peeling bark that is gorgeous. These trees grow best in a full sun to partial shade situation, and remember to give them a protected site and mulch in colder areas.
