How exotic bulbs and corms invade and threaten the bush
The ability to die back to an underground storage organ during summer enables a plant to avoid fire or drought and to tolerate nutrient-poor soils. Consequently, certain exotic bulbs or corms thrive in the bush.
Many multiply rapidly by seed, or vegetatively by producing bulb offsets, bulbils, daughter corms, or cormels. This quality, which makes them popular with gardeners, also enables them to spread rampantly through the bush, crowding out native plants on which native animals depend for food or shelter.
By far the commonest way these exotics reach the bush, initially, is through the dumping of garden rubbish that contains their seeds or vegetative parts such as bulbs and corms — the latter being the result of gardeners thinning out large clumps.