Onion weed (Allium triquentrum) is easily noticed in the garden or lawn as its long bulb-like leaves have a strong onion-like smell when crushed. It has stems of small, slightly fragrant white flowers. It grows from a series of small, white bulbs that are very easily spread and extend deep into the soil. It also spreads by seed. Once it is in the garden it is hard to eradicate.
When removing onion weed, don’t pull plants out as the small bulblets attached to the main bulb will dislodge and stay within the soil spreading the problem. Remove the weed by digging out the whole clump, including the soil, using a spade or trowel. Place the entire clump of bulbs and soil into a bag and into the rubbish bin. Do not put this weed into the compost bin as it will spread.
Other options include covering the area of weeds with weed mat, cardboard or thick wads of newspaper to smother the weed and stop it growing and reproducing. Leave in place for at least 12 months.
A well-mulched garden and dense, vigorous lawn can help keep onion weed at bay as there isn’t any room for them to grow. Feed gardens with a liquid fertiliser such as PowerFeed All Purpose including Natives, to encourage active plant growth and discourage weeds through competition and shading. Fertilising lawns with Seasol for Lush Green Lawns or Seasol for Buffalo Lawns during the growing season will keep the lawn dense and resistant to weeds.