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How to Use Glyphosate

Glyphosate is the active ingredient in Roundup and several other popular herbicide brands and is used for weed control in the garden and lawn. Glyphosate is a contact or non-selective herbicide, which means it will kill or damage any plant where the glyphosate contacts the leaves or green wood. It can also be taken up by the roots of trees if the glyphosate is sprayed around the root base of the trees and it soaks into the soil. Therefore, using the proper procedures when applying glyphosate is important.

Spray glyphosate on a day when there is no wind to prevent the fine spray from drifting to desirable plants.

Mix glyphosate according to directions. Using too much will cause the glyphosate to linger in the soil where it can cause damage to future planting. You should wait three weeks after spraying an area with glyphosate before putting in new plants.

Calibrate or adjust the sprayer nozzle so that the spray is suitable for how the glyphosate will be used. For example, if the spray is too fine it can be carried by the wind. If the spray is too hard and straight it may splatter onto desirable plants.

Spray leaves of weeds you are trying to control to the point of runoff. Do not spray under the root zone of trees. This area, also known as the drip line is full of shallow tree roots that can take up the herbicide and cause damage to the trees. Never use glyphosate to control suckers or the small trees sprouting out of the root system of a larger tree. The herbicide will immediately enter the tree's system and damage to the tree can occur.

Spray glyphosate early in the day when weeds are not heat stressed or wilted. Plants that are heat stressed cannot soak up the glyphosate spray and effectiveness is greatly diminished.


A sprayer hood is an easy-to-use device that attaches above the spray nozzle of a hand-held or backpack sprayer and helps prevent spray drift allowing you to work closer to desirable plants.


Use rubber gloves and safety glasses when working with glyphosate or any other garden chemical. Read and follow directions on all garden chemical products carefully. If used in the lawn, glyphosate will kill the target weed and any turf grass around the weed that the glyphosate contacts.

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