How do I control grass weeds in a new fine fescue ready lawn?
Hi everyone, hoping for some advice.
Our builder laid our ready lawn in December 2025 – it’s a Chewings / Red Fine Fescue lawn, and we’re in North Canterbury.
We’ve now got a range of weeds popping up, and I’m trying to work out exactly what they are so I can treat them properly. Some look broadleaf, but others, look like Couch or Poa so I’m not sure about. If anyone can help identify them?
Also – I’ve been told two different things about what to do next:
– The ready lawn team said I should scarify it
– But I’ve also been told that because it’s still such a young fine‑fescue lawn, scarifying now could damage or destroy it
So I’m a bit stuck.
What’s the best weed killer for Chewings/Red Fescue at this stage?
And should I avoid scarifying for now and just fertilise it instead, then wait until it’s older and more established before doing anything aggressive?
Any advice? Thanks in advance
It’s probably best to follow RL advice they deal with this day in day out, did they say to use a herbicide or wait? Fine fescue does need scarifying 1-2 times a year, I’d suggest getting one of those battery Ryobi scarifiers they’re not overly expensive and you can run it over the lawn a couple of times a year. What products have you applied since it was laid? Looks like it might be time for a granular.
@Garry Bainbridge Thanks Gary - RL said to go to mitre 10 and get any weed killer so he wasnt overly helpful there! Appreciate the advice. We got given some fertilizer from RL but it was just a Yates New Lawn Fert and that was back in early Feb - I will get some All Season but just wanted to treat the weeds first!
@Deana Lyons yeah that’s pretty bad advice, the herbicides available there won’t touch the weeds in those photos, they know that too! Follow what Jonny has has said regarding that side of things. Seems like they try to wash their hands with customers once the lawn is installed.
@Garry Bainbridge I did get that impression too! Appreciate the advice - let's see how we go with killing the weeds and some fertilizer! 😄
You can safely use NZLA Halo on this fine fescue. Normally you’d wait around 6 months from seed, but since this is instant turf (ready lawn), it’s already established so you’re fine to apply now.
Apply evenly across the lawn at 15ml per 100m². Just bear in mind it won’t touch broadleaf weeds, but I can’t actually see any there, I’d presume you’re mainly dealing with grass weeds at this stage.
Make sure your sprayer is calibrated and you’re applying the correct rate, overapplying is where people run into issues and damage or kill their new lawn.
Thanks Jonny, I will put a order through today!
Yes mainly grass weed but there is few boradleaf popping through.
Appreciate the advice will be sure to check calibration on the sprayer
@Deana Lyons With it being a relatively small area, if it was me I’d get in there with a hand-held weed puller and take out some of those bigger ones by hand. I can see Poa in there, which Halo will control, but you want to stop those seed heads spreading.
Just keep in mind Halo can take up to 3 weeks to really show results, so pulling a few of the more established weeds now will help tidy things up in the meantime.
I’d also back up what Gary mentioned, a light scarify (not too heavy or deep) followed by a granular fertiliser will improve the overall look pretty quickly.
During peak broadleaf germination periods you can use NZLA Meso (Tenacity) as a pre-emergent. Apply it and water it in, it’ll give you around 4–6 weeks of suppression on a wide range of broadleaf weeds.It’s not great on grass weeds, but it’s a handy one to understand and have in the arsenal. You may see some light bleaching, but that’s usually minimal when used as a pre-emergent and will grow out within a couple of weeks.It can also be used as a post-emergent and is pretty effective, just expect more noticeable bleaching. Worth checking the label for exactly what it controls in both scenarios. For grass weeds, Halo is the better option.
@KJ thanks KJ will definitely keep that in mind for broadleaf! Going to try Halo first amd see how we go 👍🏼