Another genus of vines worthy of attention is Hardenbergia. Two outstanding members of this group are H. comptoniana and H. violacea, known respectively as Lilac vine and Purple Coral Pea. These easily grown Australian natives are frost-tolerant and remain evergreen in USDA zones 9 to 11. The leaves are a dark, glossy green and have prominent veins. Long racemes of periwinkle-blue flowers, evocative of african violets, cover the vines in spring and summer.
Butterflies find the flowers irresistible and floral arrangers appreciate their long vase life.
These well-behaved twiners reach 15 feet, making them excellent candidates for smaller town gardens. Cultivars with pink or white flowers are occasionally offered. Forms originating in drier areas may not thrive in tropical areas and vice versa. If possible, select forms or buy seed from similar climatic zones to the area where they are to be cultivated. Propagation is easy from seed following pre-treatment to break the physical dormancy provided by an impervious seed coat.