Extension News

100 percent weed control
Mar. 05, 2014 @ 05:00 AM

Many pests exist for us avid gardeners, farmers and landscapers. Of these pests, we have insects, disease, animals and weeds. Weeds are the most visible, prevalent and difficult pest we deal with when trying produce a beautiful lawn or crop. Lately, weeds have become the hot topic in all aspects of pest control. In the agriculture sector, growers are now combating herbicide-resistant weeds, in the turf industry golf courses and sod farms are dealing with herbicide resistant grass weeds, and in landscaping more weeds are showing up that are now tougher to kill than ever before. So how do you achieve 100 percent weed control?   

Many of us have often heard the phrase “longterm investment.” Fortunately for us we have some herbicides on the market now that provide instant visible signs of weeds dying. However, it is the weeds that we don’t see that pose a true threat to our plant production. Consider basic plant morphology and physiology. Plant seeds germinate; grow vegetatively for the first part of their life where they focus their energy into stem and leaf production. After a plant has reached vegetative maturity and has accumulated enough energy in its storage compartments such as the stem, leaves and roots, it will then begin to grow reproductively where the main focus is to produce flowers, pollen and the final product, seed. Considering the plant’s life cycle, we can now interpret how the plant grows into when is the most effective time to kill the plant or “weed.”

Weeds are most susceptible to herbicide applications during the young stages of vegetative growth. The smaller the weed, the more effective your herbicide will be on killing that weed. As the weed grows and matures, the leaves on that plant develop a waxy cuticle on the outer surface of the leaf, making it more difficult for the herbicide to infiltrate the plant, leading to partial injury of the weed as opposed to a 100 percent kill. If you allow weeds to make it to the reproductive stage and seeds become visible, then you are too late to apply herbicide and get a 100 percent kill.

So how do you get 100 percent weed control? First of all, you must start by identifying your weed problems. In other words, you must know what weeds you are trying to control and when you will be controlling them. If you plan to combat these weeds chemically, then you are in for a longterm investment. The first step is to stop weeds before you see them. By using a good pre-emergent herbicide that kills weed seeds as they are germinating, you can eliminate the majority of the weed seed bank that is in your field, lawn and landscape bed. Once you notice weeds emerging and growing to 1 to 2 inches in height, begin using a post-emergent herbicide to kill those weeds before they reach maturity. Be sure to follow labeled rates when using herbicides and to select the right herbicide for killing your problem weeds. If you need assistance identifying a particular weed, selecting the right herbicide to kill that weed, and developing a longterm weed management plan, then please contact our office at (919) 775-5624.  

If you follow these steps, then you are sure to have a clean lawn, garden or landscape this spring and summer!

Kim Tungate is the Agriculture Agent — Field Crops, Livestock and Local Foods for North Carolina Cooperative Extension in Lee County.