Act now to control winter grass!

Author: Stefan Palm   Date Posted: 19 February 2018 

Winter grass (otherwise known as Poa annua or annual blue grass) is that annoying light green coloured grass that comes up in your lawn every winter Winter grass (otherwise known as Poa annua or annual blue grass) is that annoying light green coloured grass that comes up in your lawn every winter

If you have it, you’ll know exactly what I’m talking about. It produces lots of seeds and has a white cotton like root zone. It’s easy to pull out but there is always so much of it and more often than not, as soon as you pull it out, it seems to grow back. The most annoying thing about this weed by far is that it gets worse every year! This is because wintergrass produces large amounts of seed, which fall to the ground ready to germinate next year. If each wintergrass plant produced 50 seeds, you can see how quickly this plant can get out of control.

Now that we know what we’re dealing with, the big question is how do you get rid of it and how do you successfully keep it out. There are 2 methods for controlling winter grass. The first is post-emergent control and the second is pre-emergent control.

Post emergent control is where you selectively poison out the weed after it germinates (ie during the autumn and winter months). There are products such as Kerb and David Grays Wintergrass Killer that are designed to selectively control wintergrass in couch. These products only work if they are applied exactly as directed and can take a considerable amount of time to work. Control can take anywhere from 2 weeks to 2 months which can frustrating because there are often successive waves of wintergrass that will germinate giving the impression that your control measures are not working. If applied too late into the winter, it can be hard to get a result at all. 

Pre-emergent control works on the principle that you control the seed before it germinates. There are products that you can apply such as Embargo ( for buffalo lawns) and Pendi Pro (for couch and Kikuyu ) that stop the seed from germinating.  The best time of year to do this is when there are no wintergrass weeds present – eg January to March and if done properly will result in very little to no wintergrass seed popping up in your lawn come winter. Pre emergent control is by far the best way to control wintergrass. If you've been battling with it for a few seasons, try Pendi Pro. Its an absoulte weapon against winter grass. 

Comments (3)

Low cost, small qty, pre-em for winter grass in ki

By: on 15 May 2018
Is there a pre-emergent product marketed for control of winter grass in residential (up to 200m2) kikuyu lawns at an affordable price? Say under $30

Paul Munns Instant Lawn Response
Hi Dave Not that I'm aware of. It seems that companies producing these types of chemicals are registering them for commercial use (hence the large pack sizes and coverage). Products containing Propyzamide such as David Grays Wintergrass Killer (which is available in a 200g pack) will have some pre-emergent effect but not as much as a specialised active such as pendimethalin (Pendi-Pro). While Pendi Pro will cost you around $100, when applied in feb/march it will do an excellent job of stopping wintergrass seed germination.


By: on 10 April 2018
What product is safe to use for the control of Winter grass in Fescue lawn?

Paul Munns Instant Lawn Response
Hi Tamieke, As far as I'm aware, there are no products that specifically state they will control wintergrass in tall fescue. There is however a product called Pendi Pro that doesn't say it can't be used on tall fescue but it doesn't say it can either. I'll do some research with them and see if it's possible.

kerb & david graves winter grass killer

By: on 7 March 2018
are they both powder or liquid ? M y lawn is approx 90 sqare metres How much is needed What is the cost?

Paul Munns Instant Lawn Response

David Grays wintergrass killer is a powder that you mix up into a liquid and spray on (costs around $18 to cover 200 sqM). Pendi Pro is a granular fertiliser and pre- emergent herbicide all in one (costs $99 to cover 700 sqM).

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