Temperatures are one part of what helps make a growing environment. Plants also respond to the amoun of sunlight and at this time of year most plants are slowing, if not outright stopping, growth because of the diminishing amount of sunlight. However, some "weeds" are cool weather growers, winter "weeds" and will grow some even when buried in snow.

* Temperature--use when ambient air temperature is between 60 - 85 degrees F.
* Do not use if rain is expected, or if foliage is wet.
* Do not water treated areas for at least 6 hours after treatment.
* Allow seven days for plant to die.
* Recreational use may resume in a treated area after Roundup has completely dried (usually six hours although in some climates, drying may take up to 24 hours).
* Do not use in windy conditions or on water.
* In cool, dark or dry climates the effects of treatment may take longer than a week because plant growth rates are slowed and the chemical requires more time to act and the plant to die.

RU is made by Monsanto. After doing your own research, you may not still want to patronize this company.

Round-up tends to lose its effectiveness once temperatures have dropped into the upper 20's. If you haven't been that cold yet, you can spray away happily. If the weather stays cool but not cold--50's or so in the day and above freezing at night--the plants may not be growing very actively and the Round-up will be less effective. With Temps. in the 70's, 40's at night you should be in good shape.

Fall is a good time to apply Round-up to perennial weeds as they are pumping food down into their roots for winter and will pump the Round-up down into the roots as well, which is where you want it for a good kill.