Broadleaf weeds are wild plants that -- in comparison to other types of weeds -- have relatively flat, wide leaves as opposed to grassy or needle-like leaves. And while agricultural practices like tilling soil and hand-picking weeds can help in the management of broadleaf weeds, herbicides are often beneficial supplements. The best herbicides for broadleaf weeds are highly soluble and can move easily through soil and plant cells.
Sold under the brand names Banfel, Dianat, Mediben and Metambane, dicamba is a white, crystalline odorless compound. According to Cornell University, the compound is effective as a pre-emergence and post-emergence herbicide, which means you can apply it to the soil for targeting developing broadleaf weed seeds or you can apply it directly to weeds that have already broken through the soil’s surface. People commonly use dicamba for clearing broadleaf weeds from agricultural areas like range land and pastures as well as from residential areas like fence-rows and sidewalks. As Cornell University notes, the herbicide is “highly soluble” in water and “highly mobile” in soils, which means it can spread easily for covering large patches of weeds. Dicamba has a half-life of between one and four weeks, which means the activeness of the herbicide will decrease by half after this time period.
Also known as MCPP, mecoprop is sold under the brand names Mecomin, Triester, Mecopar and Kilprop. The white to light brown odorless herbicide is a crystalline compound that is effective only as a post-emergence treatment. As Cornell University notes, weeds absorb mecoprop through their leaves and then transfer it to their roots, where the herbicide interferes with enzyme production and ultimately disrupts plant growth. People commonly use mecoprop to eliminate broadleaf weeds in ornamental-plant gardens and on sports fields. The herbicide is effective against several types of broadleaf weeds including chickweed, lambsquarters, plantain, ivy and clovers. As Cornell University mentions, mecoprop has a “high mobility” in soils and typically remains active for two months.
2,4-D is a phenoxy compound, which means it destroys weeds by causing them to grow at a rapid, unsustainable pace. Sold under brand names including Lawn-Keep, Aqua-Kleen, Malerbane, Weedone, Savage and Plantgard, this post-emergence herbicide is able invade broadleaf weeds through their leaves, roots and stems. According to Cornell University, people commonly use 2, 4-D for eliminating broadleaf weeds from yards, gardens, pastures and range-lands, as well as for controlling weeds in aquatic environments, like artificial ponds. The herbicide breaks down quickly following application and has a typical half-life of one week.