Table 2. Application rates and timing of Roundup 4L(glyphosate) to obtain 90% or better control of selected perennial weeds one season later.
WeedsRate*Optimum Timing
Aster, goldenrod, dogfennel, horseweed1%First flowering
Bermudagrass2%First flowering
Blackberry1 to 1.5%Fall to early winter
Greenbrier3%Three to five fully expanded new leaves,(early spring)
Honeysuckle1 to 1.5%Full bloom(early summer)
Kudzu1.5 to 2%Full bloom(early summer)
Lespedeza1%Full bloom(midsummer)
Perennial grasses(quackgrass, johnsongrass, fescue)1%First flowering
Poison Ivy2%Two weeks either side of full bloom
Trumpet creeper1.5%Later summer to mid-fall
Manufacturer does not claim effectiveness on the product label fore the following species; however, research has shown the following to provide effective control.
Clematis vine1%After bloom until fall
English Ivy2 to 3%Three to five fully expanded new leaves(early spring)
Greenbrier3%Five fully expanded new leaves(early spring)
Japanese knotweed2%Late summer to early fall before frost
Mugwort1.5 to 2%Full flower(later summer to fall)
Passion flower1%Bloom to first fruit
Sericea lespedeza1%Full bloom(mid-summer)
Virginia creeper1%Late summer to early fall
Wisteria1.5 to 2%Six to eight weeks after bloom(mid to late summer)

*1% = 1.25 fluid ounces of Roundup 4L per gallon of water

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