Spotlight on Hardenbergia, Australian Native Lilac VineBy Jacqueline Cross (libellule)
November 2, 2008
Hardenbergia comptoniana, an Australian native was named for Franziska, Countess von Hardenberg, sister of Baron Carl AA von Hugel, a 19th century Australian patron of botany. H. comptoniana belongs to the Papilionaceae family. According to Botanary, this family name is from the Latin papilio (butterfly), after the shape of the pea and bean flowers.
The name comptoniana relates to the Compton family of Newby Hall, Yorkshire, England.
Hardenbergia comptoniana is commonly referred to as Compton coral pea, native lilac vine, wild sarsaparilla and wild wisteria.
Hardenbergia violacea seed/seed pod
H. comptoniana is a twining vine that grows to six feet high but may also reach as tall as twenty feet when allowed to grow without pruning. Being an evergreen plant, H. comptoniana lends interest to the garden throughout the year. Plant has dark green leaves and pea-like purple blooms. Bloom time is from late spring through late summer. Training the vine on a trellis will create a nice screen for a deck or patio. If preferred, it will also make a thick, tangled groundcover in areas where other plants do not do well.
Needs of Hardenbergia comptoniana:
H. comptoniana like warm temperatures and sunshine but if grown in extremely hot areas, the vine should have a little shade.
Water regularly while plant is young and then enjoy, even in drought prone areas. Once it is established, it can take quite a bit of dry weather if grown in light shade. Feed a well balanced fertilizer; I prefer compost tea, once every two to three months.
Pruning can be done after blooms fade. For a thicker vine, prune the vine only where it twines around itself. Closely watching growth will allow you to pull these limbs out and thread them into the trellis rather than having to trim them back.
It is important to note that this vine will scramble across the ground and wrap itself around other plants. Keep a watchful eye out for this tendency.
Propagation of Hardenbergia is easily accomplished by softwood and semi-hardwood cuttings in early spring. Cuttings should be rooted in a mix of 25% peat moss and 75% sand, kept moist and given plenty of light. Note that this mix can contain as little as 65% and as much as 80% sand with no notable difference in the process of rooting cuttings.
Seeds germinate easily but must be scarified before planting. An example of this can be found in Garden Terms by clicking the link above.
Perhaps an even better known species of Hardenbergia is the Hardenbergia violacea.
Hardenbergia violacea is also a twining vine. There are cultivars which have more shrub-like growth habits such as the H. violacea ‘Mini Haha'. Blooms appear from winter through spring in a variety of colors including white, pink and various shades of purple. A few cultivars are listed below.
Cultivars of Hardenbergia violacea:
‘Blushing Princess' (shrub-like, mauve blooms)
‘Bushy Blue' (shrub-like, blue blooms)
‘Happy Wanderer' (purple)
‘Mini Haha' (compact, shrub-like, purple blooms)
‘Pink Fizz' (pink)
‘Purple Falls' (purple)
These are beautiful plants, especially when trained to grow on trellises and pergolas and allowed to drape down over sitting areas of the garden.
As stated earlier, Hardenbergia prefer warm climates. Gardeners living in zones colder than zone 9 can still enjoy this lovely plant throughout the summer but it should be considered a tender perennial in those areas.
A wonderful book about Australian native flora and how to use it in the landscape;
Australian Native Plants Fifth Edition: Cultivation, Use in Landscaping and Propagation (5th Edition)
by John W Wrigley and Murray Fagg
To see more photographs of Hardenbergia violacea, take a look at Dave's Garden Plant Files.
A source for seeds right here at Dave's Garden can be found in Plant Scout.
A quick online search for mail order sources brought up Heart Garden Friends, an Australian (only) source.
In the U.S., I located it at Clifton's Flower and Garden Center.