Create a Barricade against Winter grass this Autumn

Written by Ian Thompson

Ian holds a Masters in Turf Management from Sydney University, has over 20 years experience working as a golf course Superintendent, turf manager, product formulation and development. We call him our resident Lawn genius.

When it comes to Winter it’s a great time to sit back and relax, leaving the lawn to almost fend for itself, but there’s always a few pesky weeds that pop up during this time that need to be sorted out quick smart. Broadleaf weeds like Bindii can be easily knocked down with Bow & Arrow however grass weeds like Winter Grass are a lot more difficult. They need to be treated with a pre-emergent, that is a chemical which forms a barrier in the soil and prevents them from emerging in your lawn. That’s where Barricade and Spartan come in.


What is Winter Grass?

Winter grass is an annual tufted lime green grass weed that emerges in lawns around March, depending on your location in Australia. While it isn’t a particularly ugly or harmful weed it does have the ability to become tall enough in the Winter period to add additional mowing to your schedule. It’s not in all lawns in Australia but is very adaptable and is one of the world’s most widespread weeds. We recommend pulling it out if you only have a few tufts before it seeds. If, however, you have seen a lot of it in the past it’s best to save your time and invest in a pre-emergent.


What is a pre-emergent?

A pre-emergent is a herbicide which is watered into the lawns soil and creates a barrier within the soil in the zone where the seeds like to grow. The active ingredient, Prodiamine, in Spartan and Barricade are then absorbed by the seeds roots and quickly work to prevent it from growing any further, so you won’t even see the weed. What’s great about long lasting pre-emergents containing Prodiamine is you can put them down twice a year and significantly reduce your need for weeding.


How does a pre-emergent herbicide work?

Here we are going to cover the pre-emergents containing Prodiamine, that is Spartan and Barricade. They work by forming a layer in the top 1inch of the soil where the weed seeds like to germinate. This layer forms after the product is watered in as per the label instructions.

As the weed seed of Winter Grass starts to grow the first thing it does is produce a root, that’s even before it produces a leaf. This first root is called the radicle, it goes looking for water but finds the herbicide and sucks it up, not knowing it has just caused its own demise.


When should I apply?

As Barricade and Spartan are pre-emergent herbicides the best time to apply is before the weeds like Winter grass emerge. These professional quality products last for 6 months in the soil and so putting them on a six month rotation can protect your lawn year round. It’s best to apply and have the most active ingredient in the soil when our most common (and least liked) weeds are due to germinate from the soil. These means an application in February to prevent against the March germination of Winter Grass and again in September to prevent against the dreaded Summer weeds like Crows Foot, crab grass and Summer grass.  


How do Barricade and Spartan herbicides differ from others?

These products contain an active ingredient called Prodiamine, this active is what we refer to as a pre-emergent. While most herbicides we know and use regularly are aimed at killing weeds that exist (post-emergent) this herbicide acts to prevent them from coming up at all.


Is it safe on my lawn?

As this herbicide works on grass weeds it is not recommended for use on all grass types. Barricade can be used on:

  • Buffalo
  • Common couch
  • Hybrid couch
  • QLD Blue Couch
  • Kikuyu and
  • Zoysia

Do not use on grasses not listed here such as Fescue, Rye and Bent grasses.


Does it work against other weeds?

Barricade works great against a whole range of common grass weeds that invade your lawn, including:

  • Winter grass
  • Paspalum
  • Crows Foot
  • Summer grass
  • Crab grass
  • Parramatta Grass
  • Rat’s Tail Fescue


If you have any questions about this or anything lawn related please do not hesitate to reach out to us, [email protected]

Check out

Spartan Herbicide- Pre-emergent for Home Lawns


Barricade Herbicide Pre-Emergent for Lawns


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