Bulbs that become bushland weeds

Page last updated: Thursday, 11 December 2014 - 10:13am

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Many people are surprised to learn that freesias and some of the other attractive spring-flowering plants that grow from corms and bulbs in the bush are exotic weeds. In gardens, these plants are grown for their flowers and their hardy, drought-tolerant nature. It is possible to purchase the corms and bulbs of many different plants that readily escape from gardens and invade natural habitats. Gardeners can protect the environment by choosing not to buy these plants, and by preventing invasive plants already growing in their gardens from escaping into nearby bushland.

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.


Contact information

Pest and Disease Information Service (PaDIS)
+61 (0)8 9368 3080