Sowthistle (Sonchus oleraceus) is an annual weed that grows mainly in the cooler months from seeds that germinate from autumn to spring. It is an erect, hairless, branched herb up 1m high, with a taproot and a hollow stem with milky sap. It has yellow dandelion-like flowers in spring.
It is spread by seed, which is dispersed by the wind. The best way to eradicate is to remove it before it starts to flower to prevent seeds from setting. Hand weed or dig out using a spade or weeding tool. As sowthistle has a large, long taproot, ensure to get the entire root out when removing it. Sowthistle is safe to feed to chickens.
Having a well-mulched garden filled with healthy plants reduces the space for weeds like sowthistle to invade. Feed your garden with a liquid fertiliser such as PowerFeed All Purpose including Natives, to encourage active plant growth and discourage weeds through competition and shading. Fertilising your lawn with Seasol for Lush Green Lawns or Seasol for Buffalo Lawns during the growing season will help keep weeds at bay.
Alternatively, sowthistle can also be controlled with a natural organic herbicide such as EarthCare Organic WeedKiller. It’s a glyphosate-free, non-selective, contact herbicide. Care must be taken when spraying around garden plants. Follow the directions on the container and ensure all parts of the plant are totally covered with spray. Repeat applications may be necessary.