Glyphosate ... How long before it works?

last week, a neighbour who lives a few houses away asked me to mow her lawn ... I normally pull out all weeds aswell (for no extra charge)

had a look at her driveway which is loose stones, and there were loads of weeds ... so I decided to buy some Tesco concentrated glyphosate and give them a good spray

label states that it contains 90 g/l (0,9% w/w) glyphosate in a soluble solution (not sure what that means)

label also states that one should use 100ml per litre of water when used in a handspayer

done that .... sprayed all the weeks well ... walked past her home earlier this morning and all weeds look healthy? .... so, in one week, I do not see any effect?... It never rained all week, and I sprayed early morning ... there was no direct sunlight, as the whole day was heavily overcast

do I make a stronger mixture and give them another spray? .... or do I buy a different glysophate?

I normally sort weeds by hand, so this is the 1st time I've tried this stuff

 

I've had that as well.

I used the concentrated pouches and mixed up a stronger solution (two to three times the strength recommended), which did the trick, but it does take a few days to a week to show any signs of working :D

 

About 2 weeks & then it suddenly drops.

 

thanks Ziggy and Merleword

I will have a look next saturday, and if the weeds still look healthy, I will give them another dose, but will make the strength 3 times stronger than recomended on the label

 

The highest/strongest volume of Glyphosate i've seen on the market is in the form of a product called Resolva 24.
I bought some a couple of weeks ago and it's quite good.

The usual strength Glyphosate absolutely needs several applications and the directions usually say this, then the weed can take a few weeks to die down.

 

I think you need to bear in mind it works faster, the faster the weeds are growing.
Growth is slowing now, due to dryness and the season has moved on.


I've never found it not to work, but it does take longer at certain times and under certain conditions.

 

Hi.

I normally find that although some weeds are quick to die, others can take up to three weeks to die. As pete says, the weeds need to be in full growth for the Glyphosate to be at it's most effective :thumb: Not sure if making it at a higher concentration will help though? Anyway, bear with it, it DOES work

Cheers...Freddy.

 

If it's any help, 9 days ago I sprayed some nettles coming through from a 'forgotten' bit of my neighbour's garden - this morning I noticed that the very edges of the leaves have finally begun to go brown. I usually reckon to give things like this a second dose a couple of weeks after the first.

 

I buy the concentrated Glyphosate solution and let it down to a 20:1 solution, I'll need to check what the effective chemical solution is. I find as most do that it takes 7 to 14 days to take effect , but it does kill the weed 90% of the time. Interesting what Pete said on the effectivity depending on growth rate. I sprayed some weeds in March and it had no effect Anything sprayed in May June July have been well and truly nuked :D

 

I've found that for some reason, only Roundup seems to work for me. I don't know why, the cheaper brands also contain glyphosate in roughly the same concentration, but they just don't work for me.

That said, I've found that different weeds respond at different rates. Bindweed takes a couple of weeks to show signs, nettles seem to take ages, and cleavers on the other hand, well I sprayed some with one light dose and a few days later they were very clearly dead (yellow/brown and very dead looking).

 

As there has been no rain the weeds aren`t growing. If you can give the drive a soaking you will notice the affect within 48 hours.

 

Just seen this exchange of posts on Glyphosate. This product is most effective when target weeds are growing strongly - usually spring / early summer. I note some correspondants advocate using at extra strength - not a good idea, - always keep to the recommended dilution and to be honest I find that a weaker solution than specified works well on most annual weeds. This herbicide was developed by Monsanto and their brand, Roundup is the one used by most commercial garden contractors.

 

it did work, but took nearly 2 weeks

I used commercial grade weedkiller today on 4 properties .... not sure what brand, as it was in a jerry can from the owner, who got it from a farmer

had a back pack sprayer and was told to dilute 500ml in the backpack mixed with water (I'm guessing it was 20 liltes as it is a large backpack pump action sparayer .... it was very thick (like syrup), and has a strong smell

apparantly it works in 4 days, and the site can be cleared in 7 days

time will tell

 

Dim, are you aware of COSHH laws? That is, Control Of Substances Hazardous to Health? As you were using what is, apparently, an agricultural chemical were you wearing the correct protective clothing? That is, coveralls, rubber boots, neoprene gloves and a full face protector? Do you also have an NPTC certificate for the use of such chemicals? Also, READ THE DIRECTIONS FOR USE. When using these chemicals DO NOT listen to other people, it is YOUR life not theirs.

 

wore goggles (had some glyphosate in my eyes a while ago and had 'red eye' for a few days

wore old trainers

old track suit .... garden gloves

and no .... I don't have any certificates or training .... there was no wind, so never breathed any of that ... there were no directions, as it was in a large 25 litre plastic jerry can ... I don't even know the name of the stuff

I'm still learning :(