Thinking Ahead: It’s time for Pre-emergent Herbicides. In the middle of winter, the last thing most people are thinking about are weeds or other pests in their lawns and gardens. Our Extension office usually starts getting calls in late spring and early summer about weed problems like lawn burweed.
The challenge we have is that by the time we get a call from you, the life cycle of the plant is so far along that there’s not a whole lot we can recommend to do about it. If you want to get your property ready for the upcoming outdoor season, you should be thinking about last year’s weed issues. Start planning a pre- and post- emergent herbicide protocol to prevent them.
Understanding Plant Cycles
A critical component of weed control is understanding the life cycle of the plant. For brevity’s sake, in order to effectively control weeds, you need to be 100% confident in exactly what they are (identification) and how they grow (life cycle). Identifying what the weed is and how it grows allows you to select the best herbicides or management practices to get rid of it.
If you don’t identify the weed first, or if you try to treat it during the wrong time of its life cycle, you risk doing more harm than good. Lawn burweed is a good example. By the time you have those burrs sticking in your feet during the summer, the window for controlling the weed with herbicides is gone. Those burrs are actually the seeds of the weed- even if you kill the foliar parts of the plants, you won’t affect those seeds, and they will grow the next year and be a recurring problem.
Pre-emergents
This time of year you should be thinking about using pre-emergent herbicides to help control weed problems you had last season. Pre-emergent herbicides interfere with the ability of the weed seed to sprout and germinate. Herbicides are usually most effective on annual weeds and are particularly useful in seasons like spring and fall when turfgrasses have a harder time competing with weeds.
Pre-emergent herbicides are usually safe to use in established landscapes and might reduce the number of post-emergent herbicide applications that are needed too. Please note, pre-emergent herbicides can injure newly established or overseeded lawns, so use caution if you are in one of those categories. Check out some of our herbicide selection.
