How long do you leave weeds treated with Roundup/glyphosate before removal.

[Le 47]

I have treated some areas of mixed weeds both large and small and expanses of nettles.Some was done 3 weeks ago and some 4 weeks ago.

Many of the weeds and nettles have blackened and/or collapsed into litle piles of non-descript veg matter. There are some, especially some of the nettles, which are clarly affected by the weedkiller with leaf loss and yellow leaves etc but remain upright (and defiant).

If I cut away all the weeds now will the roots have been fatally affected already or do I have to wait for total collapse for root death?

Bill

 

[Ron Avery]

Bill

Nettles are difficult to kill off because of their extensive root systems, so you have two choices, give the standing nettles another shot of roundup,  they have had long enough for a second dose to be effective, or dig them up and get the root systems completely out. If you have brambles (ronces) you will need a couple of treatments and about two weeks between treatments to be effective on an established area.

[hastobe]

If the weeds have tough, thick or waxy stems (like couch grass for

example) they can be more resistant to the glyphosate.  In this

case, crushing the plants before applying the weedkiller helps.

Kathie

[Ty Korrigan]

Hello,

 The glyphosate normally sold in the stores is of a lower strength than the stuff sold to farmers through places like Point Vert.

I normally use the 'domestic' stuff and do indead find that some varieties of grasses and larger plants, plants with waxy leaves and extensive root systems require several applications before cultivating a month or so later.

So... I use another product on nettles and brambles as well. Garlon, a selective herbicide so powerfull that if applied on a warm morning the plant is wilting by the late afternoon.

 It doesn't touch grasses or ferns though.

It is 40euros for 1 litre concentrate at Point Vert.

Incidently I have found the cheapest price for Glyphosate at Gamm Vert 36euros for 5 litres. Any-one got a cheaper source?

 Ty

[Jeanneclaire]

Hi, this does not quite answer your question, but a bit of information.  Nettles really compost well, make a good liquid food for plants, and are loved by butterflies, so before you get rid of all your nettles (which by the way shows that you have good healthy soil) compost the leaves, and save a little patch for your use.

Jeanneclaire