Dear Agony Aunt,
We’ve recently noticed a downright nasty-looking shrub on our Landcare site. It’s got large, unforgiving prickles. It’s an upright, branching shrub with white flowers and yellow fruit. The leaves are very memorable – thanks to the prickles! The plant has now grown up to around two metres tall. I was hoping to go on holiday soon, but I guess I’ll have to stay and sort this weed out?
Yours, Grounded in Greta
Dear Reader,
Yes, put that holiday on hold for a few weeks: you’ve got Tropical Soda Apple (Solanum viarum) on your hands. Although its name conjures up images of relaxing on the beach with a refreshing, fruity soda at your fingertips, there’s no time to lounge on the sands with this weed! This is a control order weed. You’ll need to report this plant to your local weed officer.
Hailing from South America, Tropical Soda Apple (TSA) can produce fruit 75 days after germinating, with potentially thousands of seeds being produced per plant per year. But it doesn’t stop there – seed has a high viability rate of 90 – 100%! Horses, deer, rodents, birds and pigs can spread TSA, and it can regenerate from root and stem material. The fruit can float, transporting seeds downstream, with seeds also turning up in contaminated fodder or soil or by sticking to vehicles.
If you’re buying cattle from up north, you’ll need to consider they may have eaten TSA, and can therefore spread the weed. Weedwise advises: ‘Hold livestock in a paddock free of tropical soda apple for at least 6 days before selling them or moving them off your property.’
So, this weed is a real get about! As the name suggests, plants grow best with a rainfall of 700 – 2000 mm per year, and has been found in pastures, floodplains, roadsides, edges of forests and cropping areas.
Let’s get down to the nitty-gritty. There are various ways to treat TSA:
By hand using a hoe or mattock. Plants need to be disposed of so they don’t reshoot from stems or seeds. Plants can be burnt in a hot fire, or contact your local council for other appropriate disposal methods.
The spray and cut stump methods can also be used, with details on chemical usage here.
If you’ve found a patch, don’t panic – there is support. Local Catchment Authorities have initial funding for TSA or state priority weeds, so you won’t be alone in treating the weed.
TSA can be a little difficult to identify, so here’s a handy 30 second clip from Rous County Council on identifying this plant, as there are some similar looking species about. It’s good to keep in mind the spread of weeds from certain areas if you’re purchasing stock, moving machinery (even lawnmowers!) soil, or stock feed:
Serrated tussock and Chilean needle grass can come from the Central West;
Sticky nightshade can come from Sydney;
Alligator weed can make its way down from the Upper Hunter.
Once you’ve dealt with your TSA, enjoy that well-earned holiday Landcare Legend!
From Your Landcare Agony Aunt
