What Is Roundup Concentrate?

Roundup concentrate is the trade name of a glyphosate-based herbicide, manufactured by the Scotts Miracle-Gro company. In fact, the company produces several concentrated glyphosate-based products under the same "Roundup" brand, each with slightly different characteristics and applications. Available in 16 oz., 32 oz. and 1/2 gallon bottles, Roundup concentrate is aimed at helping home gardeners to kill off weeds and other unwanted plants.

According to analysis by the Alabama Cooperative Extension Service, Roundup Pro concentrate contains 41 percent glyphosate. By contrast, the Roundup Weed and Grass Killer Super Concentrate formula contains 50.2 percent glyphosate. Neither formula contains any additional active ingredients. Roundup Weed and Grass Killer Concentrate Plus contains two active ingredients, combining 18 percent glyphosate with 0.73 percent diquat. Roundup Poison ivy & Tough Brush Killer Plus Concentrate also contains 18 percent glyphosate, with 2 percent triclopyr amine. To combine weed removal with preventative care, Scotts Miracle-Gro offers Roundup Concentrate Extended Control Weed and Grass Killer Plus Weed Preventer, with a solution of 18 percent glyphosate, 0.3 percent imazapic and 0.73 percent diquat.

According to trials by the Alabama Cooperative Extension Service, Roundup concentrate products vary considerably in their effectiveness against weeds. The ACES awards both Roundup Pro Concentrate and Roundup Weed and Grass Killer Super Concentrate a "very good" rating in treating foliar growth of unwanted species and an "excellent" rating for treating the cut stumps of unwanted plants. By contrast, the same trial found that Roundup Poison Ivy & Tough Brush Killer Plus Concentrate was simply "good" in both respects. ACES did not recommend the performance of any of Roundup's other concentrated herbicides.

All of the Roundup concentrates use glyphosate as their main active ingredient, an herbicide which works systemically, meaning that through application to the leaves, the herbicide travels throughout the plant's vascular system, thereby killing the whole plant. As a result, you apply all the Roundup concentrates by spraying the liquid onto the plant's leaves. As the name implies, all of the Roundup concentrates must be mixed into a diluted solution, usually water-based, before application. Consult the application instructions for your particular product before applying.

To apply Roundup concentrate most effectively and safely, take a few measures to keep the herbicide away from plants other than those you wish to target and kill. Never apply any Roundup product or any glyphosate-based herbicide directly before a heavy rainfall, as the rain will disperse the product away from the targeted plant and throughout local root systems. Avoid over-application of any Roundup concentrate; once you have covered the foliage of the undesirable plant, the leaves are unable to absorb any further herbicide. Continuing to apply the substance will only result in more Roundup making its way into the surrounding soil.