SBK treated weeds. How long before i dig the roots out? second treatment?

hi guys, my weeds (nettles, brambles, dock) are treated with sbk brushwood killer. how long should i give until its wise to dig up the weeds? should i treat twice? i treated them maybe 5 days ago and they are well wilted but still green and tall. any tips on the best way to uproot them so that they dont come back? im hoping to put grass seed down eventually on the spot where the weeds are. any tips on best preparing the soil for seeds would be great too. thanks!

 

If you`ve not had rain lately, I would suggest giving the area a good soaking, this will speed up the demise of the weeds.:gnthb: