Gazanias from our 2012 weed watch post
Posted on 2 November, 2016 by Connecting Country
The following information was originally published in 2012 by Geraldine Harris in the Castlemaine Naturalist newsletter, and has been kindly re-written by her for the Connecting Country website. we have decided to re-post it as a the Gazanias are currently in full bloom.
Some plants become environmental weeds when they escape from our gardens into the surrounding countryside and start competing with local native indigenous species. I want to look at how some of these infestations can be controlled and which native plants can be used in their place.
Our native plants cannot be expected to perform as vigorously as pest plants that have been selectively bred for survival over hundreds of years. However, getting rid of pest plants and replacing them with native species will help preserve the integrity of our local habitats, attracting and providing resources for more native birds and other animals.
Gazania linearis
Gazanias are the large daisy-type yellow flowers that are escaping from private gardens and appearing more and more abundantly along our local roadsides and in bushland throughout Victoria, South Australia, Western Australia and New South Wales.
These very showy plants originated in South Africa and are being promoted in many plant nurseries as a tough drought resistant species. Many hybrids have been developed in cultivation between Gazania linearis and a closely related environmental weed species Gazania rigens. These plants produce abundant wind-blown seeds that can be dispersed many kilometres from the source, producing ever-increasing patches of gazania that compete with locally indigenous species. Gazanias also have the ability to re-grow from their bare roots, which enables them to spread into our bushland by the dumping of garden waste containing the tuberous root systems of these plants. Native animals tend not to eat them as they are low in nutritional value.
Control methods include pulling out by hand if the infestation is small (making sure the
roots are removed so it doesn’t re-grow) or spraying with a registered systemic herbicide into the heart of the rosette. If you have a large outbreak amongst grasses or in a lawn, a broadleaf-selective herbicide maybe a much better option. At very least, remove and then bag the flower heads. The ‘bagging’ prior to disposal is important because even when the gazania flower heads are detached, most still have the ability to develop as mature flower heads with masses of viable seed.
As substitutes you could plant native daisies such as Sticky Everlasting (Xerochrysum viscosum), Common Everlasting (Chrysocephalum apiculatum) and Clustered Everlasting (Chrysocephalum semipapposum). Pigface (Carpobrotus modestus) would also be a useful substitute requiring no water and producing large pink-mauve flowers all summer.
References
Rayner C. 2012, ‘Weed of the Month’, Angair Newsletter. No 1, p6.
Marriot N.2011, ‘Plant ‘Aussies’ – not weeds’, Growing Australian, Vol 54.3, No 216, p12-13.
I like them on the road side !
they,re pretty and colorful in spring!
Most weeds are pretty in one way or another–look at the great displays of Oxalis we had this year!
The problem comes when they take over, and push out everything else. Personally, I’m a bit sick of them. It seems as if every town from here to Mildura has them crawling all over their streets. I’ve never seen them in the bush, though.