I'm looking for some advice because we're not too happy with the weed killer we've been using. Our lawn and garden are about 200m². So far, we've tried:
Kiwicare 2L Lawnpro Turfclean And Green Rapid+ Hose Pack
https://www.bunnings.co.nz/kiwicare-2l-lawnpro-turfclean-and…
Yates Weed n Feed Lawn Weed Killer and Fertiliser 4 litre
https://www.mitre10.co.nz/shop/yates-weed-n-feed-lawn-weed-k…
We're now considering the Kiwicare Turfclean Ultra Concentrate 800ml, which was recommended by someone at Mitre10:
https://www.mitre10.co.nz/shop/kiwicare-turfclean-ultra-conc…
I've also come across glyphosate in my research:
https://www.sprayshop.co.nz/products/ken-up-glyphosate-360-5…
Here are my questions:
What's a good product that gives decent results without costing too much?
Should I be using the same product for both the lawn and garden, or different ones?
Should I spray the entire area, or just focus on problem spots (precision strike)?
The first three products kill weeds and leave grass alone (selective herbicides). Glyphosate will kill everything (non-selective herbicide).
Generally selective herbicides are going to be slower and less effective than non-selective herbicides like glyphosate. Glyphosate can be got very cheaply from Mitre 10 and Bunnings home brands as a concentrate. If it doesn't work fast it enough, blends of glyphosate and more potent weed killers like saflufenacil will be faster but more expensive and more toxic.
If you are spraying in your garden carefully in-between plants or carefully only on weeds in your lawn, a non-selective herbicide like glyphosate is what you want. If you to spray your whole lawn you want a selective herbicide. I can't really speak to selective herbicides as I let anything grow in my lawn if you are trying something new check to see if the active chemicals are different. If one brand of a chemical doesn't work for you another brand of the same chemical won't either.