Active ingredient
Glufosinate-ammonium
Phosphinic acid (glutamine synthetase inhibitor, Group 10)
A non-selective herbicide that is not glyphosate and does not behave like it. The label we read names the mechanism itself: a Group 10 herbicide, a glutamine synthetase inhibitor, which makes ammonia accumulate in the tissue the spray wets.
What it does
Burns down emerged annual and perennial grasses, broadleaf weeds and some woody species, and it does it fast — the label we read is rainfast in four hours. That speed is the reason people reach for it where glyphosate is unwanted or has stopped working.
What it does not do
It barely translocates, so it is not a root killer. What the spray misses survives, and perennials with rhizomes or tubers regrow from below — so it will not finish bermudagrass or nutsedge. It is also not a lawn product: the only turf site on the label we read is fully DORMANT hybrid or common bermudagrass before spring green-up, and the label warns of severe injury or delayed green-up otherwise.
The label constraint people miss
One of the two labels behind this page carries a county-level prohibition: not for use in Nassau or Suffolk Counties, New York. The same label caps the year at 80 fl oz per acre and three broadcast applications. And read this page's product list with one eye open — for the second product we have confirmed the registration but EPA hosts no label, so its rates and sites are not label-sourced and we say so on its page.
Products we review that contain it
Every product below is here because we opened its label — on EPA's own database or the registrant's — and read Glufosinate-ammonium in the ingredient statement. Registration numbers are on each product's page.
Non-Selective Contact Herbicide (glufosinate concentrate)
Liquid Harvest 24.5% Glufosinate Herbicide, 32 oz
★★★★☆ (3.9/5)
The main glyphosate alternative — but NC State is clear it does not translocate to roots, so perennials come back.
Best for: A fast glyphosate-free burndown of annual weeds and seedlings, where regrowth from perennial roots is acceptable
$35–$44
View on Amazon
Non-Selective Contact Herbicide (glufosinate, agricultural volume)
Tide International Glufosinate 280 SL Herbicide, 2.5 Gallons
★★★★☆ (4/5)
Acreage-scale glufosinate for glyphosate-resistant weeds — with the same limitation as the small bottle: it does not reach roots.
Best for: Acreage-scale burndown where glyphosate resistance is the problem and repeat passes are expected
$90–$110
View on Amazon
Guides that use Glufosinate-ammonium
Buy for the active, then read the label anyway. Two products with the same active are not interchangeable — concentration, labelled sites and species tolerances all vary, and a three-part registration number means a narrowed label. How to read one in two minutes. Where our page and your container disagree, the container is the legal authority.