How long do I need to leave weeds sprayed with glyphosate before digging them into the ground and laying turf?

Question

I have a very weedy lawn area. I want to strim it, then spray glyphosate to kill these weeds, then I want to cultivate it, rake it, fertilise and lay turf on top. But how long do I need to leave the weeds after spraying? Like can I just spray them and dig them in straight away, and they will die? Or do I need to leave them a couple of weeks until their brown, before digging them in?

Answer 1

firstly do not strim the weeds on you lawn as glyphosate is whats known as a translocation herbicide. this means it is sprayed onto the foliage of the plant and then moved around the plants to the roots and so kills the plant. By removing the foliage will stop this happening. to answer the time taken befor digging in usualy the glyphosate is taken into the plant after ten hours. this must be a dry period with no rain or the glyphosate will not work. do not spray untill you are happy the weather is going to be fine.try to just wet the foliage as any liquid that runs to the ground will be neutralised.after this time you can then dig the weeds in.

Answer 2

HF gave a good answer, I might add though, it depends on the weeds. If you are dealing with some honkingly deep rooted monster weed, say bindweed, I'd wait more than 36 hours! Those roots go 80 feet! Also it's been my experience bermudagrass takes a second spraying after 7 days to completely kill out. So the answer is......patience grasshopper. Don't cut or cultivate for awhile and do continue to water those weeds a bit so they remain healthy enough to take in the glyphosate. Wilted plants do take in the herbicide.

Answer 3

I'm a farmer and spray glysophosphate in pre-harvest situations when we want to destroy the crop being harvested (so it will not re-grow). The label says to wait 36 hours. This gives the chemical time to translocate to the root system.

Do not remove any foliage before spraying, the leaves are needed to move the chemical into the root system.

Contrary to other answers, this chemical will not cause any damage whatsoever to future planting. This can be sprayed, then new lawn planted. This can be sprayed on top of new planting as long as absolutely no new foliage is available to make contact with the chemical (after planting, but before emergence).

My experience is that 30 minutes after spraying is enough to make the chemical rain-fast (meaning a good soaking rain will not affect the spray job). The label says longer, but my experience says it does the job in 30 minutes or less before a rain soaking.

THe more healthy your plants are, the better the kill. This chemical also works better on grasses than broadleaf (lower rates give better kill on grasses). Try not to spray with moisture on the leaves (dew or otherwise), but it would probably still work. Hope this helps.

Answer 4

That depends on what herbicide you use. If it's a broadleaf herbicide such as 2,4D, you can probably lay the turf the next day. If you're using a broad spectrum herbicide like RoundUp, you'll have to read the label directions.

Answer 5

You need to wait until they are brown and dead so the spray will kill all the plant roots before you dig them up

Answer 6

Gee, have you considered not using glyphosate at all??? It worries me that this powerful poison is being sprayed around with such abandon.... After all, it does end up in the rivers and oceans.....

Answer 7

if you can you are better removing as much of the weeds as possible then there is no risk of poisioning the new lawn