Recently a report has come through of a C1 weed category bulb identified in native bushland in the Peel region. The only other confirmed population of this bulb species is in Victoria. All C1 declared pest are actively excluded from WA and is the highest control level attributed to declared pests. C1 prohibited organisms may only be imported and kept subject to permits. Permit conditions applicable to some species may only be appropriate or available to research organisations or similarly secure institutions.
Declared bulb species can be purchased over the internet on international sites. However, the importing of plant material into Australia is highly regulated due to the biosecurity risks. Australia’s Biosecurity Import Conditions system (BICON) has all the information you need to know about any plant material you may want to purchase over the internet, including whether or not the plant is declared and/or not permitted.
The recent finding of the high risk bulb in the Peel region has highlighted the need for gardeners to become informed on the pest potential their garden bulb species may have, especially since pest plants escaping from private gardens is the most common way of becoming established in bushland.
Bulbs and what they mean for the bush-
Bulbs are plants that are generally spring flowering and reproduce and spread from corms and bulbs. In bushland they can quickly become a problem as the corms and bulbs are protected in the soil from extreme weather conditions and the plants are also drought tolerant. The bulbs can even be protected from fires and herbicide use allowing the plant to continue to spread.
Black flag (Ferraria crispa) is a popular bulb purchased due to its unusual succulent looking bracts and leaves, even with an unpleasant odour from its black flowers. Black flag has a high reproductive capacity and will seed prolifically, producing stacked corms that make it very hard to treat with chemicals.
Chincherinchee (Ornithogalum thyrsoides) is extremely invasive and highly toxic to livestock. This bulb should be carefully considered before planting if the surrounding landscape includes farmland, lifestyle blocks, national parks or urban reserves.
How do they get into bushland?-
The most common way ornamental gardening species find their way into bushland is through inappropriate management and disposal. The illegal dumping of garden waste in bushland areas creates a big problem in the spread of declared and invasive weeds.
When working on bulb species in the garden bag up any plant material, soil and/or the corms or bulbs. Leave the bag out in the sun for a couple of weeks before disposing into the general rubbish, you can also solarise larger areas of soil using plastic sheeting. Be aware that composting alone will not kill the corms or bulbs and gardeners should always be aware of the dispersal of plants and seeds from their own garden into the wider area. If you live close to natural bushland areas or alongside livestock then think hard about what you introduce and cultivate in your private garden.
Please do not dump garden waste into our native bush and make sure you bag up loose corms or bulbs when disposing of garden waste. Declared pest management cost the entire community so do your part.
What shall I do if I see one?-
A list of the common bulb species found in our bushland can be found on the Department of Agriculture and Food website. If you see a bulb species out in bushland then use the MyWeedWatcher App to report it. You can also contact the Peel Harvey Biosecurity Group for control information on declared pests.