Native Wisteria (Hardenbergia comptoniana) Growing Guide

What is Native Wisteria?

Belonging to the Fabaceae family, this legume native to Western Australia is a favourite to both ornamental gardeners and wildlife enthusiasts. Fabaceae all have iconic papilionaceous-shaped flowers referring to the overall butterfly-like look.  

Wisteria is known for taking a long time to flower, often only flowering after several years of ownership. However, Hardenbergia isn’t a wisteria and flowers straight away!

Its foliage is an ideal habitat for native wildlife. It is dense, clinging and climbing, but also provides thick ground coverage too. Along with this shelter, our native wisteria also provides a valuable source of food in Southern Australian winters through spring for wildlife when other sources of pollen may be scarce. 

Native wisteria is evergreen and boasts dark green, glossy leaves that can be really quite linear to slightly ovate and leathery to the touch. 

Australian Wisteria’s Natural Habitat

Hardenbergia are endemic to Australia, they occur in all states and have proved to be adaptable to growing in a wide range of climates and soil types. They have spread themselves across coastal regions from Geraldton, down to southwestern Australia where they occur through Jarrah Forest to Albany. More recently, they can be found naturalising in central New South Wales.

Native wisteria seems to find success in sandy soils, sand plains and dunes but is also found growing in forests and clay-based areas. Known as pioneer plants that can colonise disturbed or hostile soil, perhaps after a bushfire or surface erosion, native wisteria sets the path for future flora. 

Hardenbergia can rapidly grow over these hostile and difficult areas of land providing ground cover, soil stabilisation and, most importantly, a reintroduction of a native ecosystem.

Common Uses for Native Wisteria

Most commonly used as an ornamental, Hardenbergia comptoniana is often planted to screen fences and walls as its fast-growing habit and evergreen leaves make for an easy and effective, dense display. 

Used in this way, native wisteria can be an excellent form of privacy, providing a blanket of leaves and beneficial flowers compared to other plants commonly used for privacy screens.

Creating a native wisteria screen can also provide a windbreak for other plants that may need a sheltered position, and also give much-needed shade for plants that can’t tolerate direct light. 

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When planted around a pergola or archway, even up against a building, Hardenbergia will reward you with masses of flowering racemes, perfect for showcasing an arbour, pavilion or covered way.

Native Australian wisteria’s use as a re-vegetative species is common given its fast growth and benefit to local wildlife. Alongside this, native wisteria’s root system and dense foliage will help prevent soil erosion. 

Planted along creek lines where there is a high risk of water erosion or around sloped firebreaks where the soil structure is fragile and immature, native wisteria can protect the surface and give much-needed structure.

Even in coastal sandbanks where the risk of high winds can erode dunes and embankments, Hardenbergia proves to be a beneficial and crucial part of re-vegetative and erosion control measures.

The native wisteria is also used by indigenous Australians to make rope. The vine itself is used and woven together to make nets and traps.

Are Native Wisteria Edible?

All parts of Hardenbergia comptoniana are poisonous and can cause skin irritation for some people when handled. There are no known edible uses, though there are some references to Hardenbergia violacea’s use as a tea. This isn’t suitable for H. comptoniana. 

Refer to our guide to find out more about growing Hardenbergia violacea.

How to Grow Native Wisteria

This plant is simple to grow and is adaptable to various soil types. It spreads freely and will happily self-seed, however, if you want to get the heat flowers from your native Australian wisteria or keep its growth in check, there are some growth conditions it prefers. 

Ideal Conditions for Growing Native Wisteria

This Hardenbergia species generally prefers to grow in a sun part shaded aspect in your garden. However, for an abundant display of those beautiful purple to almost blue sweet pea-like flowers, native wisteria would prefer a position with a good supply of sunshine. 

Soil & Drainage

Hardenbergia comptoniana is very flexible in its soil preferences. It can grow in very sandy conditions and very clay-based soil. Depending on the soil type and whether it is in a very free-draining, dry location, its growth may be slightly smaller but, once mature enough, native wisteria can tolerate periods of drought. 

Light & Temperature

Native wisteria’s part-sun, part-shade preference gives it the best of both worlds and keeps it within a reliable cycle but it will thrive when grown in warm climates, and will not tolerate cold, requiring full protection from frost. 

Shelter

Grown in very hot areas, Hardenbergia will need some form of sheltered protection. When young, it will need a regular watering schedule to help develop a good root system, but once established native wisteria will tolerate periods of drought providing it has that crucial shaded shelter. 

Planting Hardenbergia comptoniana

One of native wisteria’s best traits is its fast-growing nature, but this can be to the detriment of other surrounding plants. Be aware and vigilant of its neighbours, as this plant can twine around and smother other companion plants, eventually killing anything that cannot hold its ground. 

Within a garden setting, growing up a trellis and monitoring its blueprint, native wisteria will happily grow alongside your other garden planting and complement ornamental schemes beautifully. 

How to Propagate Native Wisteria

Another interesting fact about native wisteria is the behaviour of its energetic seed pods. On very hot days, Hardenbergia comptoniana has an explosive dispersal system.

Triggered by heat, an audible pop can be heard as the long, rounded, brownish-purple pods open and the seeds are propelled away from the mother plant. All unripe seed pods are green before maturing.

The seed is 6mm in diameter, ovate, brown and has a small whitish aril appendage attached to the seed. Ants are attracted to this aril as a food source so collect and bury the seeds. Again, this makes this plant a master of self-propagation.

Propagating from Seeds

It is very easy to grow your own native wisteria from seed, but it must be stressed that seed should be obtained from a reputable source. Seed should not be collected from wild plants as these may be part of re-vegetative schemes. 

Seed can be purchased from many specialist Australian native plant suppliers. 

Seed is prepared by soaking overnight in warm water to aid germination, or gently nicking the seed coating. Both practices are known as scarification. Germination can take between two weeks and two months.

Sow your seed in peat-free compost, 6mm deep, sparsely in a seed tray - or two to three seeds in a single pot. Water well and keep the soil moist until germinated by covering with a propagator lid. 

Place your native wisteria in a warm but sheltered position to germinate. 

Propagating from Cuttings

Hardenbergia can also be propagated from cuttings by using non-flowering softwood or semi-hardwood material in early spring or as the plant starts to put on new growth. 

Choose a length of stem that has at least two nodules and remove lower leaves. Insert into a free draining peat-free compost with added perlite or vermiculite, water well and cover to keep moisture in. 

Caring for Native Wisteria

Caring for native wisteria is straightforward, they do not need much pruning to encourage growth but may need pruning to restrict growth. 

Pruning Native Wisteria

Its fast and vigorous growth can create a competitive environment where your native wisteria will almost always come out on top. To stop it from winding around your other plants and using them for support, provide strong, substantial climbing frames and train the plant towards them. 

This plant will happily take any hard pruning as it can grow up to 3m high and 2m wide. It is important to remove any dead, diseased or dying branches throughout the year, and if a gentle tidy is needed after flowering, remove those spent flowers by cutting back to the next set of leaves.

Repotting Native Wisteria

Hardenbergia are very adaptable to growing in a pot and can be maintained more easily when doing so, especially in smaller gardens. Container-grown native wisteria may need repotting occasionally if it has used up all available nutrients or if you want to maintain vigorous growth and flower production. 

By potting into a larger pot for growth encouragement, or dividing the root ball and replenishing it with compost to maintain its size, native wisteria will be triggered into much healthier growth. It benefits from any peat-free compost and the occasional bark or leaf litter mulch. 

Hardenbergia comptoniana does not need much fertilisation when grown in the ground, but container-grown native wisteria can benefit from an organic fertiliser specifically for native planting. 

Native Wisteria Pests and Diseases to Look Out For

Hardenbergia comptoniana are susceptible to occasional attacks from regular garden pests such as mealy bugs, spider mites, and scale insects. Additionally, it serves as a food source for caterpillars.

Keeping the balance between a healthy organic garden and a perfectly ornamental one, where everything looks good all the time, can always be hard but it is possible. Having the right environmental balance of predatory insects and animals to take out the ones you do not want is always the best way. 

Usually, these garden pests will not damage your native wisteria to the point it won’t recover so trust in nature to tackle the problem. If you need to intervene, a sharp blast of water will dislodge any visible infestations. 

Hardenbergia comptoniana can be affected by mosaic virus which causes yellowing leaf spots and deformed new growth with a puckered and blistered appearance. 

Known to affect both H. comptoniana and H. violacea, mosaic virus is spread through other infected plant foliage and by aphids, whiteflies and other visiting pests. 

Removing all infected foliage from the plant and the surrounding area will help to prevent the virus from spreading to other Hardenbergia, but a heavily infected plant will need to be removed and disposed of. 

Elsinoe hardenbergia fungus is known to infect young plants, particularly reported in nursery-bred Hardenbergia where airflow is not adequate and immature plants are too close. It causes discoloured patches on the leaves and stems of native wisteria, infected parts rot away and further infect other plants in close proximity. 

Keeping proper airflow and watering will reduce humidity around plants and can help prevent the environment where the fungus will thrive. 

Native Wisteria Frequently Asked Questions

What is the inflorescence of Hardenbergia comptoniana?

The inflorescence of Hardenbergia comptoniana is a drooping terminal raceme, 10-15cm long made up of dozens of individual purple flowers, each 1-15cm across. Each flower is made up of two standard petals, with two wing petals forming the identifiable form, followed by a string of cylindrical pods.

Is Hardenbergia a wisteria?

Hardenbergia and wisteria are two separate genera in the same family (Fabaceae). Hardenbergia is native to Western Australia and identifiable from Wisteria in its flower and leaf forms.

What type of plant is Hardenbergia?

Hardenbergia is a woody, evergreen climber, with evergreen foliage. It is structurally a perennial shrub, but with long twining stems that allow it to climb where possible. Otherwise, it will grow in a self-contained mound or as ground cover.

What is the leaf shape of Hardenbergia?

Hardenbergia has distinctly lance-shaped leaves on more mature growth, but younger growth typically holds shorter, egg-shaped foliage.

What are other common names for Hardenbergia comptoniana?

H. comptoniana is known by many common names, but the most popular are native wisteria (in Australia) and false sarsaparilla.

What is the best fertiliser for Hardenbergia comptoniana?

The best fertiliser for H. comptoniana is either an annual mulch of well-rotted horse manure or a regular liquid feed of an organic native plant food.