Definition Of hardiest
robust; capable of enduring difficult conditions.
The traditional cattle are hardy breeds which can cope with the tough upland climate.
Example Of hardiest
a hardy breed of cattle
a favorite flowering shrub for early spring, vigorous and hardy
A gardening neighbor had a small cold frame in which she grew hardy flowers for early and late blooms.
Ah, well I'm particularly interested in your range of hardy Geraniums.
Although the tubers themselves are winter hardy , a mulch layer is highly recommended.