Growing Hardenbergia violacea
General planting and care
Hardenbergia violacea, purple coral pea or false sarsaparilla, is a climbing or prostrate plant found in many parts of Australia. A number of varieties have been developed for gardens including Flat White™ and Carpet Royale™, both in white and mauve. These are fast growing, low maintenance, heavy flowering, shallow rooted plants with long trailing stems forming a dense mat, and unlike most other varieties of Hardenbergia, these can be used in a variety of positions in the garden as they do not climb.
A full sun to part shade position is preferred in a wide range of soil types including light clay or sand however, these cultivars will grow best in an enriched, well drained acid soil on a raised bed with a pH of 5.5 to 6.0.
They possess a low frost tolerance when young and can sustain significant leaf damage but will become hardier with age.
We recommend that you do not transplant Hardenbergia violacea once established.
Avoid wetting the foliage to minimise possible fungal problems. Monitor watering levels in the first season after planting and during the warmer months of the year to maintain adequate soil moisture.
Fertilise with a general purpose three to four month slow release fertiliser in spring and autumn. Supplementary applications of a complete liquid fertiliser at two to threeweekly intervals will assist with plant health and vigour.
A liquid feed of magnesium sulphate (Epsom salts) and iron chelates in April will also assist in maintaining strong vigour prior to flowering especially in sandy soils.
After planting your Hardenbergia, we recommend to mulch to a depth of 5 cm to conserve soil moisture and to assist with plant health.
Heavy pruning, up to two thirds of the plant, after flowering will increase vigour and create a bushier plant with increased flowering in the following season.
Pests and diseases
Hardenbergia violacea are susceptible to powdery mildew during cool moist weather and should be monitored and treated with an appropriate organic fungicide, if necessary. Fungal problems can be minimised by avoiding foliage wetting during irrigation and by periodically removing dead leaves to improve air circulation.
Monitoring plants for evidence of leaf damage should be carried out to avoid major pest infestations, such as lead chewing caterpillars. Scale insects and mealy bug can also become a problem in crowded situations.
The Hardenbergia violacea varieties Flat White™ and Carpet Royale™ are available for purchase from most good garden centres.