MOORE — Did your lawn fall under attack from weeds last year? Do you want to get a head start on controlling them this year? Or maybe you are thinking about doing your own lawn care instead of hiring out? It seems that weed control is on everyone’s mind. So, what to do about those pesky weeds in your green acres?
It is almost time to apply our first round of pre-emergent. A pre-emergent affects weed seed that is lying in wait ready to sprout. So it must be applied before you see any weeds present. The time to apply pre-emergent in the spring to control summer weeds can vary from year to year.
The best rule of thumb is to apply your pre-emergent when the forsythia in your area begins to bloom. This is the first thing to bloom in the spring. Forsythia is a large, woody shrub with bright yellow flowers along the stem. This striking shrub tends to bloom in late February to early March. With correct timing and application, a spring-applied pre-emergent can provide 80 to 90 percent control of common summer weeds.
What type of pre-emergent do you need? There are many products available to treat for summer blooming weeds now. But there are tons of different brand names and manufacturers.
The best way to look for a pre-emergent is to check the active ingredient on the bag. Some of the products I recommend contain these active ingredients: benefin, trifluralin, bensulide, dithiopyr, pendamethalin, oryzalin or prodiamine.
If you have problems with Sandbur, in particular, along with other grassy weeds, products containing oryzalinare are recommended.
In addition to a pre-emergent, correct fertilization can help your lawn thrive and outcompete weeds, especially Sandbur.
For Bermudagrass lawns, the ideal time to begin fertilization is May 1. If you are unsure what type of or how much fertilizer to use, I suggest getting a soil test.
In addition, if it has been more than five years since your last test, you will want to test again for up to date recommendations.
Soil for testing can be done by collecting 15 to 20 soil plugs per area. I suggest you do one soil sample (each consisting of 15 to 20 plugs) for each area that you would like tested.
These areas could be a vegetable garden, flower bed, lawn, etc. The soil plugs should be collected to a depth of 6-to-8 inches deep.
Remove any sod, rocks or mulch and mix the soil plugs together. This gives you a representative sample from the entire lawn area and a more accurate result from the OSU Soils Testing Lab.
From the mixture of soil plugs, bring a full, quart-size baggie to our office for testing. Routine soil tests are $10.
If you have an OSU Extension office in your area, the collecting procedure is the same.
If you have winter weeds that are nice and green already, a pre-emergent is not applied to target those now. Pre-emergents for winter weeds are applied the third week of August in our area of the state. Do not apply products containing glyphosate (RoundUp) in your lawn past the first week of February, as you may end up with dead spots during green up.
Visit oces.okstate.edu/ cleveland for detailed Fescue and Bermuda grass maintenance calendars or feel free to contact one of our Master Gardeners at 321-4774 or firstname.lastname@example.org if you have questions regarding lawn weed control.