That claim is basically marketing exaggeration.
No weed killer reliably does “kills weeds in 1 day and they never grow again” in a permanent way. Here’s the reality:
Most fast-acting products (like glyphosate-based herbicides) can:
- Start wilting weeds within 24 hours (sometimes visible burn within a day)
- Kill the plant down to the root over several days
But they do NOT stop weeds from ever coming back, because:
- Weed seeds remain in the soil for years
- New seeds blow in from wind, birds, animals
- Roots of some species regrow or spread underground
Even very strong products like:
- glyphosate (systemic herbicide)
- glufosinate (fast contact herbicide)
…still only kill existing growth, not the soil seed bank.
What actually prevents regrowth?
If your goal is long-term control, it takes a combination:
- Mulch or landscape fabric (blocks light so seeds don’t sprout)
- Pre-emergent herbicides (stop seeds from germinating)
- Regular removal (before plants reseed)
- Ground cover plants to outcompete weeds
If you want, tell me what kind of area you’re dealing with (garden, driveway, farm edges, etc.), and I can suggest a realistic long-term solution that actually works in practice.
