Pre-Emergent Primer

This January was the sixth-warmest on record, and February is following suit. While many are hoping for at least a little winter before we start the application season, it’s definitely time to get our heads back in the game and ready for pre-emergent applications. Here are some tips and tricks to remember as we get going.

Calibration

Calibrate your equipment and perform any necessary maintenance before the season begins. Properly calibrated equipment and well-trained applicators are every bit as important as the product that they apply.

Our friends at Steel Green Manufacturing have a couple of videos on how to calibrate your equipment. For granular calibration, you’ll need a scale, a measuring bin, a bucket, a measuring wheel, and cones to measure off the distance and spread width of the machine. For liquid calibration, you’ll use the swath width, speed, and nozzle output to calibrate the machine.

Timing

Timing is everything. Many are itching to start slinging product with these warm temperatures, and it’s especially tempting to get ahead given today’s labor market. Beware, though, as pre-emergent herbicides applied too soon will break down by microbial or sunlight degradation and fail later in the season when you need them most.

On the flip side, we all know that pre-emergent herbicides are not effective once seed has germinated. Crabgrass will germinate when soil temperatures hit 55° for four to five days in a row. Forsythia blooming is a good indicator that you should be wrapping up pre-emergent applications. If you get behind, a full rate of Dimension will provide both pre-emergent and post-emergent crabgrass control through the three to five tiller stages.

Lastly, consider the timing of split applications. If you’re making split applications, be mindful of making your second application in a timely manner to ensure consistent coverage.

Breakthrough Prevention

Watch the edges and pass spacing. Property lines and along driveways and sidewalks are where we usually see crabgrass breakthrough. Road salts and increased compaction definitely can be a factor, but most of the time, breakthrough can be attributed, at least in some part, to misapplication.

Rotary spreaders are designed for 50% overlap (wheel-to-wheel application). Applicators will often “cheat” and space their first pass away from the concrete and throw right to it, resulting in a lower rate applied in that area than needed. Many don’t even realize they are making the error. The correct method is to throw beyond the concrete and use a blower to blow back into the turf.

Spreader Cleaning

Check and clean off buildup on spreader impellers, as this will affect the spread pattern and reduce control. This tip isn’t specific to pre-emergent applications, but remember to keep an eye on side deflectors that can drop as they are used, causing striping and poor herbicide coverage.

Fertility

Finally, remember that the best defense against weeds is healthy turf. A well-designed and implemented fertility plan is the foundation, and we have many tools for you to achieve that.

Scott Sand
Sales Manager