Hardenbergia
Hardenbergia violacea
Wider than it is tall, and untroubled by most of what lands on it — only sodden roots do real harm.
- Type
- Shrub · Perennial
- Botanical family
- Mixed / other
- Foliage color
- Green
- Flower color
- Purple and violet
- Sunlight
- Full sun
- Feeding
- Rose & flower
- Frost tolerant
- Yes
- Flowering
- July
- Apr–Jun Dormancy
- Jun–Jul Bud Break
- Jul–Sep Flowering
- Sep–Dec Growing
- Jan–Apr Growing
- Plant spacing
- 8 ft 2 in
- In-row spacing
- 8 ft 2 in
- Between rows
- 10 ft 3 in
- Square-foot density
- Not suited to SFG
- Root system
- Woody, and deeper than the stem suggests
- Working depth
- 24 in–4 ft
- Can reach
- 6.5 ft down where the soil allows
- Spread
- 8–16 ft across, about 1–2× the width of the plant
- Shallowest pot
- 20 in of soil
A vine puts far more below ground than its one thin stem implies, and that is where the alarming vigour comes from. Give the root run depth and drainage at planting; it will forgive almost anything done to it above ground afterwards.
A legume, fixing its own nitrogen, which is why it climbs happily on poor ground and resents being fed.
The habit is Hardenbergia’s own; the figures are what that habit usually comes to at this size, not a measurement of this species. Roots follow the soil either way: a compacted pan, a high water table or heavy clay stops them well short of any of it, and deep open ground lets them go further.
- Leaf miners Leaf miners, cosmetic rather than harmful
- Mealybugs Mealybugs on the young growth
- Scale insects Immobile brown or white bumps fixed to stems and leaf undersides, sucking sap and weakening growth. Wipe off with a damp cloth or dab with horticultural soap; watch for the sooty mold that follows.
- Root & crown rot Root rot in waterlogged ground
Beneficial predators that hunt this plant's pests — grow their favourite flowers nearby to recruit them. companion plant
- Hoverfly Syrphidae
Bee-mimicking flies whose legless larvae graze aphid colonies clean while the adults pollinate. A ribbon of shallow, nectar-rich flowers kept in bloom all season recruits wave after wave of them.
- Ladybird (lady beetle) Coccinellidae
The gardener’s favorite ally: adults and their alligator-shaped larvae each eat thousands of aphids, plus scale, mealybugs, and other soft-bodied sap-suckers. Grow flat, open flowers for the adults and never spray a colony that ladybird larvae are already working.
- Green lacewing Chrysoperla carneaHunts Mealybugs
Its bristly larvae — "aphid lions" — impale aphids, mealybugs, thrips, and mite colonies, eating hundreds a week. Adults feed on nectar and pollen from small open flowers and overwinter in hollow stems left standing.
- Parasitic wasps Braconidae & TrichogrammaHunts Leaf miners
Tiny, stingless wasps that lay eggs in or on caterpillars, aphids, and moth eggs — the white cocoons riding a hornworm are their calling card, so leave that caterpillar be. Umbel flowers with shallow nectar keep the adults fuelled.
Grevillea, Westringia, Correa, Dianella, Lomandra
Green-leaved shrubs, like this one.
The Cottage Garden Companion — the gardener's herbarium at cottagegardencompanion.com