Should I be doing a general lawn weed spray in winter?
I have a NZLA Dark Perennial Rye lawn and while its looking pretty good I have noticed a few weeds here and there along with perhaps some Poa sprouting up. Should I be doing a general lawn spray of Etho, Gold, Meso or BWC?
I was historically doing a weed and feed type routine and conscious of the fact that i now have been focusing on health and growth via the NZLA guidelines (Which is giving great results) but i want to remove some of the small weeds and Poa that is popping up.
Only thing you should be doing through winter is pre emergent Etho applications. Save the rest for spring.
No point doing herbicides over winter, uptake will be poor as the weeds are not active enough to uptake the herbicide, leave it for when growth speeds up.
With air temperatures low and weeds barely growing, NZLA Gold and BWC aren't going to perform well. Foliar herbicides rely on the plant actively metabolising for uptake to happen. Spraying those weeds in mid winter won't really do anything. Hold off until air temperatures improve and the weeds are clearly growing again. A targeted application then will be far more effective.
For the Poa, it depends on where you're at (or if it's even Poa). If it's well established, post-emergent control in winter is largely a losing battle. The plant just isn't active enough for the product to work effectively and you're better off waiting until early spring when it starts pushing growth again. If the Poa is young and you've caught it early, there's still a window. Two applications of Etho 14 days apart, first one watered in, can knock back young plants that are still susceptible. The older and more established it is the harder it becomes to control.
Prevention is the better approach. Ideally you want to be heading into winter with no Poa present and a pre-emergent programme running, applying every five to six weeks and watering it in to stop those seeds germinating. If you've got Poa now because pre-emergents weren't down, the time to tackle it is early spring when it starts pushing growth again and a post-emergent will actually work a bit more quickly. You could pull mature plants manually and focus on pre-emergents to stop it getting worse from those prolific seeds. It's hard to offer advise when there's no photos.
Etho and Poa is an in depth topic and I find myself constantly writing about, as there’s many factors at play. There's a lot of information already in this forum, on the Facebook group, and on the website, worth spending some time going through that.
Don't go near your lawn with Meso when growth is slow. The temporary bleaching will last for the rest of winter and into spring. Meso is a great pre-emergent option heading into peak broadleaf germination when soil temps pick up. I normally put a Meso application down as a pre-emergent the last week of August and that sits in the soil at the time when we start seeing lots of broadleafs popping up because the conditions are right.
If a few weeds are bothering you in the meantime, pull them by hand, this should be part of your lawn routine anyway, it makes such a difference. Keep in mind that turf is already under stress in winter, conditions just aren't favourable. The last thing you want to do is add more stress to an already difficult situation with herbicide applications.
@Jonny Hicks i always get lots of lighter grass come up over winter.. would putting down meso as pre-emergant be a good idea to stop these cool season weed grases coming up? I plan to do a double Meso app to get rid of the foreign winter grass going into a spring with a dethatch and overseed. just wondering if a Meso pre winter would be any help. NZLA perennial rye with a bit of FF so cant Etho. Dont have any other photos but this is normally what the patches look like that come up over winter. Cheers