Weed ID Chart. 10

Turf Weed ID Chart

The turf weed ID chart

This is an easy-to-use turf weed Identification chart for Australian turf weeds, including lawn weeds. This discusses the conditions that favour common weeds and what your weed control options are. At the end of this article is a section on using identifier weeds.

Firstly three key points in regard to weed identification in turf.

The first thing is, if you use this turf weed ID chart and identify the weed in your lawn or sportsturf you don’t always need to spray a weedkiller. Many weeds usually indicate underlying soil problems so if you deal with these first it discourages the weeds and avoids using 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!

Turf weed control chemicals.

Herbicides and weed control products are classed in several ways:

• pre-emergent herbicides or post-emergent herbicides
• contact or systemic and
• selective or nonselective.

You use pre-emergent herbicides before weeds emerge and they kill weed seedlings as they germinate and try to establish. They have no effect on weed seeds and are mainly used against grass weeds like winter grass and summer grass although some pre-emergents are 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.

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 causing injury throughout the target weed. Examples are glyphosate, quinclorac, triclopyr, 2,4-D, dicamba, and mecoprop mixtures (an active ingredient in many 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.

Turf weed ID chart

Weeds A-C 

Burr medic 

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

Cats Ear 

Crowsfoot

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

Weeds D-N

Flickweed

Nutgrass

Prefers moist, high fertility soils and occurs from September to March. Use Monument or Prosedge 750W.

Weeds N-W

White clover

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, Monument, Contra M, Duke, or Quinstar.

Turf Indicator weeds

Weeds are very helpful as they tell us the health of a soil. Once you identify a weed using the turf weed ID chart you can use the table below to discover what conditions favour it. For example, if you have bindweed then carrying out a soil aeration program will create less favourable conditions and possibly mean you do not need to use a herbicide in the future.

After using the Weed ID chart how to get the best results.

1. Correctly identify them. 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?
2. A healthy actively growing turf surface is the key to stoppng 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.