The turf weed ID chart

This easy-to-use Australian weed Identification chart allows you to identify common lawn weeds from a photo. Being able to correctly identify a weed is crucial to getting the best herbicide performance.

The weed identification chart isn’t simply a collection of images of common weeds in Australia. This weed identification chart discusses the conditions that favour common lawn weeds, including grass weeds and creeping weeds in lawns.  However, it also briefly outlines how to manage these and what your weed control options are. At the end of this article is a section on using identifier weeds.

Firstly, three key points about weed identification in lawns.

The first thing is, if you identify the weeds by photo by using this weed ID chart you don’t always need to spray a weedkiller. Correct Australian weed identification can have the added benefit of saving a considerable amount of time and effort in the future. The reason for this is many lawn weeds usually indicate underlying soil problems. So if you deal with these first, it discourages lawn weeds and avoids having to use turf chemicals. More on this later.

The second thing is that weeds can be either grass weeds (monocots) or broadleaf weeds (dicots). If you can see the weeds when they are seedlings you will get a good start on identifying them. Grass weeds have one seedling leaf and broadleaf weeds have two seedling leaves. Broadleaf herbicides do not control grass weeds.

The third and most important thing is if your lawn or turf is thick and healthy, weeds find it very hard to get a hold and you probably won’t even need to use this Australian weed identification chart!

 

Lawn weed control chemicals.

Herbicides and weed control products are classed in several ways:

  • Pre-emergent herbicides or post-emergent herbicides;
  • Contact or systemic;
  • Granular or liquid and
  • Selective or nonselective.

You use pre-emergent granular herbicides before weeds emerge. These kill lawn weed seedlings as they germinate and try to establish. They have no effect on lawn weed seeds and you use these mainly against grass weeds like winter grass and summer grass.  Some pre-emergents are however, effective against broadleaf weeds. Pre emergent herbicides can be either liquid or granular pre emergents.

You apply post-emergent herbicides after weeds appear and they control growing weeds. They can be either contact or systemic like the sulfonylureas. So the new alternative to Monument herbicide, Recondo herbicide falls under this class. Correct Australian weed identification is important if using post emergent herbicides as these are not all equally effective against all weeds.

Contact herbicides cause injury where the chemical contacts the plant. They work best when you apply them to young weeds and examples are diquat, carfentrazone, plant oils, and herbicidal soaps.

Systemic herbicides work better on older weeds and move within the plant and cause injury throughout the target weed. Examples are glyphosate, quinclorac, triclopyr, 2,4-D, dicamba, and mecoprop (an active ingredient in some broadleaf weed killers).

Selective herbicides kill weeds without damaging turfgrass species as they are toxic to only certain plants or weeds. e.g. 2,4-D kills only broadleaf weeds and not grasses. Non selective herbicides kill all vegetation including turfgrass.

More product information is available in our turf chemicals section or in this free Guide to turf pesticides. Do realise though that correctly identifying weeds by photo using the weed identification chart is important so you know what lawn chemical to use in your arsenal.

 

Turf weed ID chart

Identify weeds by photo A-C

Bindii

This photo of the weed Bindii is in the Australian weed identification chart

Thrives in low light and wet soils. Use one of 3-D, Casper, Recondo herbicide, Contra M, Duke, Warhead. Appears from May to October.

Bindweed

Field Bindweed flowering

Prefers compact soils

Black Medic

Black medic flower. The Australian weed Identification chart avoids the confusion that can occur between this weed, oxalis and white clover

Favours dry, low fertility and compact soils. Use Casper, Recondo turf herbicide, Contra M or Duke.

Burr medic 

Burr medic

Germinates in the autumn and winter, and flowers in the spring. Prefers poor, heavy clay soils.

Buttercup oxalis

wood sorrrell is often confused with other weeds. The Australian weed identification chart makes identifying this a snip.

Aka Wood sorrel and soursob. Prefers low calcium levels and drought. Use 3-D, Casper, the alternative Monument herbicide, Recondo, Contra M, Duke, or Warhead Trio herbicide.

Capeweed

Capeweed

An indicator weed that shows high fertility soils. If the weed is stunted and has a yellow colouration it indicates low nitrogen. It also indicates compact soils and that the turf cover is thin. Often seen in high wear areas where the turf has thinned out.

Carrot weed

Australian weed identification is easy using this weed ID chart.  This is carrot weed

Also known as common cotula or button weed this favours drought, low fertility and compaction. Control using one of Casper, Recondo herbicide, Contra M or Duke.

Cats Ear 

Catsear
Aka Flatweed or false Dandelion. Low fertility conditions favour this weed. Use 3-D, Casper, Monument, Contra M, Duke, or Warhead.  

Chickweed

Chickweed

An indicator weed indicating wet, compact soil and low light levels. Control by using 3-D, Casper, Monument, Contra M or Duke herbicide.

summer grass

Summergrass with seedhead

For post emergent control of summergrass use Gauntlet or Quinstar. With Quinclorac based products use Voltage MSO adjuvant. Best pre-emergents are Onset 10GR, Battalia or Echelon.

Creeping Mallow

Creeping mallow

If conditions are favourable, most mallows behave as short-lived perennials. Use Contra M

Crowsfoot

Australian weed identification of Crowsfoot weed with its distinctive seedhead

Prefers wet, low fertility and compact soils. Post emergent control with Destro and Tribute. For Pre-emergents use Barricade, Battalia or Specticle herbicides.

Australian weed identification. Weeds D-N

Cudweed

Cudweed

Is a problem all year round. Use 3-D, Contra M, Duke herbicide, or Warhead herbicide.

Dandelion

This photo in the Australian weed identification chart shows the distinct flower of the weed, dandelion
Prefers compact, low fertility soils. Is a problem from May to August. Use 3-D, Casper or Contra M.

Flaxleaf Fleabane

Identifying the weed Flaxleaf fleabane is easy using this photo from the Australian weed identification chart

Can occur all year round. Use 3-D, Casper or Contra M. Image courtesy of Weeds of Melbourne.

Flickweed

Flickweed is a common turfgrass weed that favours damp, recently disturbed soils.

Aka hairy bittercress. Found in damp, recently disturbed soil. Occurs in two periods: February, March And April and then August, September and October.

Khakiweed

Khakiweed

Use Casper. Establishes in spring and summer.

Lambs Tongue

Lambs Tongue

Aka Ribwort or narrow plantain. Prefers low soil fertility, droughty and acid soils. Can occur all year round. Use 3-D, Casper, Contra M or Warhead Trio.

Knotweed

A photo of Knotweed allows you to identify this weed using the weed ID chart

Appears from August to March in droughty, compacted and acid soils. Use Casper or Contra M.

Nutgrass

This photo shows how you can easily identify the weed nutgrass using the weed ID chart

Prefers moist, high fertility soils and occurs from September to March. Use Recondo herbicide or Prosedge 750W. Can be managed organically. Don’t pull out by hand.

 

Weeds N-W

 Guildford Grass

Identify Guildford grass (onion grass) using the turf weed ID chart by its purple flower

Aka onion grass. Use Duke herbicide.

This is indicates low soil fertility.

Paspalum

Australian weed identification when you use the weed id guide is easy.  This is paspalum.

Prefers wet, high fertility soils and is a problem from October to February. For post emergent control use Gauntlet and/or Tribute. Barricade or Onset 10GR are good pre-emergent options.

Slender speedwell

Slender speedwell grows on all soil types, in particular moist soils

This weed grows on all soil types, and likes wet soils

White clover

this photo show how easy it is to identify white clover with its distinct leaves

This is an all year round weed, and prefers droughty, compact soils with low fertility. Chemical control is easy if you use one of 3-D, Casper, Recondo turf herbicide, Contra M, Duke, or Quinstar.

 Winter Grass

You can identify Wintergrass easily. This photo shows its distinct  seed head and boat shaped leaf tip

Favours wet compacted soil, low light and low soil fertility. It generally appears between March to October. Post emergent control: Monument, Duke, Checkpoint, Tribute. Pre-emergent: Barricade, Battalia and Specticle.

After using the Weed ID chart to identify weeds by photo

  1. Correctly identify weeds by photo. A weed is only a weed if its a plant where you don’t want it. Also if you don’t know what it is how can you control it properly? So use this Australian weed identification chart carefully;
  2. A healthy actively growing lawn surface is the key to preventing weeds. If your turf is healthy you are less likely to get weed issues;
  3. Always read the label and MSDS sheet on any turf chemical you are going to use.
  4. Make sure that the herbicide you want to use is safe to use on your turf;
  5. Spot treating is always a good first step. If you use a spray marker dye it allows you too see where you have treated and avoids double treating areas;
  6. In some situations when the weed population is too high you are looking at a blanket application;
  7. A post-emergent herbicide works best when weeds are actively growing. Applying to turf under stress will tend to give poor results;
  8. Some post-emergent broadleaf herbicides, like dicamba, cause tree injury if applied too close to the tree drip line;
  9. The key to success for all pre-emergent herbicides is to apply 2 to 3 weeks before weed germination;
  10. Pre-emergents work best when the soil is moist but the turf is dry at the time of application. Water them in properly as soon as possible after application;
  11. If you are applying pre-emergents, you cannot seed for several weeks or months after application and finally
  12. It is much more difficult to control weed grasses in turf with post-emergent herbicides. So use pre emergents to prevent these becoming a problem.

 

FAQ

What is the best way to manage weeds in lawns?

The best way is to stop them growing in the first place. A healthy, thick and dense grass cover will stop weeds growing. Weeds are great opportunists so if the grass is weak and struggling to grow, there are thin patches or the soil is compact weeds will grow. 

If weeds still continue to be a problem then the using pre emergent herbicides is worth considering. These work by stopping weed seedlings from developing and vary in longevity from 10 weeks to 8 months. So basically you can apply once and have no weed issues for this length of time. 

Remember though, that you need to know what the weed is that you are trying to control as not all pre emergents work as well against all weeds.

Why is weed control important?

In agriculture weeds are a major problem as they dramatically reduce yields. In a turf situation we generally don’t deal in yield but weeds will limit turf growth by taking valuable nutrients and water away from the grass.

Weed control in couch lawns

The simplest way of controlling weeds is too hand pull them. However, in some cases weeds can be too widespread too effectively hand weed. Then I guess it depends if your trying to control grass or broadleaf weeds.
If the couch goes dormant (totally browns out over winter) then you can simply apply glyphosate and it will kill all the weeds no matter if grass or broadleaf. Adding a spray buffer or an appropriate spray adjuvant will guarantee the best possible results.
If your wanting to control weeds in couch when it’s growing then use a broadleaf post emergent herbicide is the way to go. If you want to stop them from becoming a problem use a pre emergent herbicide.

What can I use to kill weeds in my lawn without killing the grass?

The first option is too hand weed by simply pulling out the weeds. However, be aware that this can actually cause the problem to worsen I.e. nutgrass.
If the weed infestation is widespread then consider using a selective herbicide. Which one will depend on whether they are grass or broadleaf weeds and which particular weed.
Senior Turf Agronomist at Gilba Solutions Pty Ltd | 0499975819 | Website | + posts

Graduated from Newcastle University with an Hons Degree in Soil Science in 1988, Jerry then worked for the Sports Turf Research Institute (STRI) as a turf agronomist before emigrating to Australia in 1993.

He followed this by gaining a Grad Dip in Business Management from UTS. He has worked in a number of management roles for companies as diverse as Samsung Australia, Arthur Yates and Paton Fertilizers.

He has always had a strong affinity with the Australian sports turf industry and as a result he established Gilba Solutions as an independent sports turf consultancy in 1993. Jerry has written over 100 articles and two books on a wide range of topics such as Turf Pesticides and Nutrition which have been published in Australia and overseas.