A horizontal underground stem that sends out roots and shoots. Distinguishes many plants including ginger, turmeric, iris, and many grasses. Rhizomes store energy and allow plants to spread laterally and regenerate after disturbance.
Rhizomes are modified plant stems that spread horizontally underground, functioning as both storage organs and reproductive structures. Unlike tubers, rhizomes continue growing indefinitely and produce shoots and roots along their length. In Australian gardens, rhizomes are particularly valuable because many native plants—such as gingers, kangaroo paws, and various orchids—use them to establish resilient root systems that withstand drought and recover quickly after fire.
Common Australian plants with rhizomes include Alpinia (native ginger), Iris species, and many ferns. These plants thrive in zones 8-12 across Australia, from tropical Queensland to temperate Tasmania. You can propagate rhizomatous plants by carefully dividing the rhizome into sections with at least one growth point, ideally during autumn (March-May) or spring (September-November) when plants are dormant or emerging.
When planting rhizomes, ensure good drainage and avoid burying them too deeply—the top should sit just at soil level. Incorporate compost or organic matter from local retailers like Bunnings to improve soil structure. Rhizomatous plants generally require minimal fertiliser once established, though a balanced slow-release fertiliser applied in spring supports vigorous growth. In warmer zones (9-12), established rhizomes provide excellent groundcover and erosion control while reducing watering requirements.