A lush weed-free expanse of green lawn may not be top of everyone’s gardening wish list, but it sure comes close!
There is a sense of achievement when the grass has been mown, the edges trimmed and unsightly weeds removed. Of all those tasks, getting rid of weeds in the lawn seems to be the most troublesome and time consuming.
What are lawn weeds
When we refer to lawn weeds we’re most often talking about broadleaf weeds – plants like dandelions, plantains and thistles that our early settlers brought with them from the old country to make them feel more at home in this inhospitable land.
However, broadleaf plants are not the only lawn weeds. Some grasses are also invasive and tend to be weedy, like winter grass and paspalum. Eradiating a pest grass in a lawn isn’t all that simple, because some of the products used to kill them may also harm popular lawn grasses like buffalo, for example. If you have a winter grass or paspalum problem, it’s best to talk to a turf specialist to see what they recommend that won’t damage your lawn.
Top 11 most common lawn weeds
Clover
Growing vigorously from late autumn into winter, clover should be treated with a selective herbicide in mid to late winter, before it flowers. It may take two applications 6-8 weeks apart to gain effective control. Mowing to remove flowers before they set seed will also assist in reducing carryover from one year to the next.
Creeping Oxalis
While creeping oxalis seems easy to pull out, each small segment or leaf left behind will root and continue the spread. It thrives over winter and flowers in early to mid spring. It may take two or three applications of a selective lawn weeder from mid winter into spring to eradicate it. It is essential to control creeping oxalis before flowering and setting seed.
Bindii (Jo-Jo, Onehunga)
While bindii are fairly easily pulled out, the use of a selective herbicide formulated to effectively control bindii before it has the chance to flower and produce burrs is essential. The first spray should be in winter, as soon as the first young plants are seen. Two or possibly three repeat applications at six weekly intervals from the first should give you the upper hand before summer. Keeping your lawn well fertilised and healthy is the best defence against bindii.
Capeweed
Capeweed is closely related to the sunflower. It thrives in poorly maintained lawns, so one key to eradication is to ensure your lawn is well fed and watered and without bare patches where this weed can gain a toe-hold.
Capeweed seeds germinate in autumn and the weed thrives over the winter months, flowering in early spring. Two treatments six weeks apart with a selective lawn weeder over winter should control it. Controling capeweed before it seeds is imperative for good control.
Chickweed
Chickweed is a “cool season” weed, rarely found once temperatures start to warm up in spring, so it’s important to eradicate it before it sets seed for carryover to the following year.
Great handfuls of chickweed can be pulled off lawns and garden beds, but it is essential to make sure the roots come out too, otherwise it will quickly re-sprout. Another weed that takes advantage of lawns in poor condition, it is easily controlled by lawn weeder products applied when the weed is actively growing but your best defence is to keep the lawn well fed and mown.
Cudweed
One of the true broadleaf, flat weeds that is a major pest in lawns, cudweed (Gnaphalium sphaericum) is prevalent in winter lawns, when it grows vigorously and out-competes most lawn grasses. Cudweed starts with one rosette-like plant with smooth green leaves (white on the underside) but quickly develops into an expansive group that can smother out extensive areas of lawn.
Like most other weeds, it’s important to gain the upper hand in winter, before plants flower in spring and then set seed. Hand removal using a pronged lawn weeder tool is quite effective. Selective broadleaf lawn weeder products will also control it, although it may take two applications 6-8 weeks apart.
Dandelion
Possessing a sturdy taproot and growing in a flat rosette, the dandelion is invasive, smothers lawn grasses and thrives over most climate zones. While it is most active in winter and its main flowering is in early spring, dandelion will flourish at almost any time of the year, often during even the harshest of conditions. Controlling dandelions before it produces its fluff-ball seed heads is vital. It can be removed with a pronged lawn tool (make sure to remove the taproot entirely or it will regrow) or with a lawn weeder.
Dock & Sorrels
Like most broadleaf weeds, docks will smother lawn grasses, leaving unsightly bare patches when they are either dug out or killed. They flourish over winter when lawn growth is generally slow and flower in spring and early summer. They can be controlled with one or two applications of a selective herbicide in early to mid spring before they set seeds.
Fleabane
It can be quite hard to control because has tough, woody stems and spreading roots. Like other flat weeds, if allowed to develop into colonies, it will smother large areas of grass. Because it is common on waste lands and its seeds are airborne, it can be quite invasive.
Fleabane grows strongly over the winter months then flowers and seeds from mid spring right through to autumn. Like all lawn weeds, the best time to apply a lawn weeder is while plants are actively growing in late winter but before they start to produce flowers.
Lambs Tongue Weed(Plantain)
Lambs tongue grows over winter, seeds freely in spring and summer and spreads rapidly but is reasonably easy to eradicate in late winter using lawn weeder products. A follow-up application may be needed for complete control.
Wireweed (Knotweed)
Wireweed seeds germinate in spring and summer, so effective control with a selective herbicide is best when plants are actively growing over late spring into summer – before it has the chance to set seeds.
Wireweed thrives in poor soils and occurs in neglected lawns in many parts of the country. While it is not often seen in lush urban gardens, it is considered an environmental weed of national significance. Wireweed can be difficult to control, sometimes needing more than one treatment.
So there you have it – 11 of the most common lawn weeds to invade Australian gardens. Most are persistent but can be eradicated completely with the right treatment and perseverance.
