Have you spent hours hand pulling weeds in your lawn or simply looking at yards around the neighborhood and wondering why your lawn is full of weeds and the other are not? The answer is most likely the application of proper timed pre emergent. Pre emergent herbicides work by creating a chemical barrier in the top layer of soil that coats the seeds and prevents them from growing roots and shoots.
The Benefits Of Pre Emergent and Myths of "Weed & Feed"
During the spring time you will hear countless ads on the radio for applications of Scott's turf builder plus, or other "weed and feed" products. The honest truth is you are already too late.
Weed and feed applications do nothing as a preventative measure. It is already too late. The weeds have germinated. The weed part of the "weed and feed" is actually a post emergent. It will only kill the weed if it is directly applied to the growing plant. If you listen closely during the fall, you will hear a few ads running for applications of fall/winter pre emergent. The truth is these are the most effective as treatments but not effective as marketing as most people are not thinking of their lawns this time of year. The marketing dollars are not well spent. The big retail companies have learned, the money better spent on selling "weed and feed" then selling the more effective fall/winter pre emergence.
The proper timing of applications depends on the type of weed you are trying to control. Typical applications occur early in the spring before warm season weeds appear and in the fall for cool season weeds. These treatments have a "shelf life" so ti is important to do multiple applications so you can control the weeds. There are some weeds like dandelions that do not have a pre emergent control and inevitably some may slip through the cracks. No application can be 100% effective however it is much easier to deal with any remaining weeds that manage to escape this treatment.
The main benefits of pre emergent treatments are many. First the weed is eliminated before it is even visible. Second there is a minimal amount of labor to apply pre emergent. Third it is more easily to deal with remaining weeds that manage to escape this treatment. Finally, each following season the need to spray a post emergence weed killer is reduced.
The Drawbacks of Pre Emergent
Like stated earlier, not all weeds have pre emergence treatments so there will always be a need for post emergent treatments on lawns.
Pre emergent will inhibit the growth of new grass seeds. If you plan on planting grass seeds, do not apply pre emergence. You will have to plant the grass and then treat any weeds with post emergence applications.
Timing is critical. A pre emergent is NOT effective once the weeds are visible. The chemical must be situated PRIOR to the weed seed starting to germinate. If you wait you loose. This does not mean to wait till next year. You will still be in a better place if you start to fertilize and use post emergence on the weeds that show up. But be cognizant you will need a full season of treatments before you will get ahead of the situation.
Even applications are necessary. Many times you will see a yard that appears to be painted green. This is not the color of the pre emergent. Instead it is a dye to allow the applicator to see where he or she has treated to ensure an even application. Any small untreated area will allow for weeds to grow.
It must be watered into the soil to be fully effective. Each herbicide is different. Make sure to follow the instructions on the label or the watering instructions provided by your application company. Not following the directions will limit or eliminate the effectiveness of the application.
Yes, it is a chemical. Many people prefer to avoid another chemical, however, application of pre emergence is minimal compared to many post emergence treatments and leaving its chemical on the foliage to be effective. It is what it is. There are many organic options, but they are more expensive, less effective, and shorter lived than the chemical type.
A pre emergence has to be re applied. Depending on where in the country you live, you may need 2-3 applications due to the different types of weeds and different germination times. In addition, most pre emergent applications only last 60-90 days so you will need repeated applications. You will also have to re apply these treatments year after year for the best lawn.
Please let us know if you have any questions regarding pre emergence, fertilization and weed control and remember prevention is better than cure!
The College Fund Family