Pot War: When and How to Use Chemical Herbicides

Sometimes, despite our best efforts, it is time to bring out the big guns of weed management: the compounds. Think carefully before using chemical herbicides on the landscape, and make certain they are part of an integrated pest management approach that includes:
Identifying the particular problem plant.Understanding the plant’s life cycle. Can it be an annual or a perennial? Does it spread by seeds, seeds or both? If it spreads by seed, when does this germinate? Using cultural (growing conditions that discourage weeds) or mechanical way of command, whenever possible. Recognizing when and the way the weed invasion may cause catastrophic damage to a natural habitat, either harvest or structure.Once you’ve determined that an herbicide is the proper step in handling your weed problem, you can evaluate the options and select the right product for your circumstances.

Jocelyn H. Chilvers

First, let us get familiar with the terminology. Herbicides act as pre-emergents, by inhibiting plant seeds from germinating, or as postemergents, which means they operate on actively growing plants.

Some are nonselective and affect any crops they contact, while some are selective and will control only particular crops.

Contact herbicides impact only the plant cells on which they are applied, while systemic Compounds are absorbed into the whole plant and plant system.

Chemical controls may be natural or synthetic. Ideally, all herbicides must be applied by a certified pesticide applicator.

Jocelyn H. Chilvers

Natural Herbicides

The active ingredients in natural herbicides come from minerals or plants. These products are subject to government regulations for private and environmental safety. Read all product labels thoroughly and follow along with care.

Corn gluten free meal. The protein component of a corn kernel is a selective, pre-emergent herbicide most commonly utilized to control annual weeds — including as oxalis, purslane and spurge — in lawns. It is also about 10 percent nitrogen, therefore it helps promote nutritious turf. Corn gluten meal is most successful when applied two times a year. Apply it before the seed germinates and forms a root. A dry period after germination is also vital. Find out more about timing corn gluten meal programs here.

Vinegar. It is a nonselective, postemergent and contact herbicide for annual weeds. Apply horticultural vinegar alternatives, which have less than 20 percent linoleic acid, as a spray into the weeds’ foliage. The acid acts as a contact desiccant (“burning” the foliage but not the roots) and can be most successful when applied to annual weeds in the heat of summer.

Soap. Horticultural soaps, derived from fatty acids, which are nonselective, postemergent, contact herbicides. Sprayed about the weeds’ leaves, the item smothers the foliage, inhibiting the crops’ growth. Horticultural soaps are most effective in young, actively growing, annual weeds.

Iron. The newest kid on the block employs a 1.5 percent option of FeHDTA (a iron chelate) as its active ingredient. A selective, systemic, postemergent herbicide, the applied iron dose is toxic to a number of common broad-leaf weeds but does not have a detrimental effect on turf grasses.

Jocelyn H. Chilvers

Synthetic Herbicides

Synthetic herbicides have artificial elements subject to government regulations for private and environmental safety. Remember: Read and follow product labels carefully.

Glysophate and glufosinate ammonium. All these nonselective, systemic herbicides could be effective on poisonous perennial weeds like field bindweed, myrtle spuge and quackgrass. Research shows that a very particular application regime — the time of year, the phase in the plants’ life cycle, and also the method of application — is vital to the most efficient and beneficial use of this herbicide.

2,4-D and Tryclopyr. Both these chemicals are selective, systemic, postemergent herbicides useful for controlling many annual and perennial broadleaf weeds like puncturevine, kochia, Canada thistle and orange hawkweed. They are effective on weeds in lawns and round conifers.

Your local Cooperative Extension Office will have significantly more research about the best way best to identify and manage the weeds in your region.

More:
5 Ways to Naturally Grow the Weed War
Tackle Weeds the Pure Method
5 Weed-Smothering Ground Covers

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