View Full Version : Pre emergent did not work so well
08-22-2000, 06:27 PM
How best deal with a customer that has crab grass coming on.
We applied pre emergent at the end of Feb and again 6 weeks later.
SAME PROBLEM. OUR LAWNS THAT SHOW SIGNS OF CRAB WERE THE ONES THAT WERE BARE,SPOTTY,NO SPRINKLER SYSTEM OR ONES THAT STARTED THERE SPRINKLER SYSTEM LATE,OR NO RAIN UNTIL SOIL TEMPS GOT UP TO 50+DEG...AFTER APPLICATIONS. I USED DIMENSION AND PEND.I AM HAPPY WITH THE RESULTS THIS YR.I EXPLAINED THE ABOVE TO THEM ALSO WE GOT A LOT OF RAIN IN THE NORTHEAST.
Theres been so much rain in my area that it's been breaking down the pre-emergent barrior. Thats why some of my lawns have more crabgrass than usual.
08-23-2000, 04:23 PM
Your problem is that pendimethalin (sp?) ...oh, heck, call it pre-M...is only good for 16-20 weeks. In the Northeast this means an application in spring and another around July.
08-24-2000, 04:14 AM
16-20 weeks is extremely generous.
The reality is the crabgrass seeds from the previous season attempt germination and are killed by the crabicide in the early spring.
Sure, the longer the window, the better, but with good irrigation and healthy turf, even TEAM, with 4-6 week effectiveness prevents most crabgrass.
08-24-2000, 08:31 AM
We had good luck against crabgrass on known problem lawns especially since we mostly applied 2 apps of pre-emergent - either Pendimathalin or TeamPRO - first in earlymid April, then again in Late May. Here in CT, a lot of people started putting down their first app in March, and that was a mistake, because it was way too early. Both the TeamPRO and Pendimathalin labels show that a repeat application is most effective. For late additions to the list, we applied Dimension, and in some cases even repeated a Dimension app.
We have been putting a lot of new lawns in all season, and this has proven to be an ok year for that sort of gamble. For crabgrass breakthrough on the new lawns we applied 2 apps of Siduron spaced 4 weeks apart, and there was enough rain to ensure it got watered in. This worked for the most part. I used Drive Postemergently to control crabgrass and broadleaf on new or recently seeded areas. This product seems to work very well.
08-24-2000, 12:08 PM
In fact Drive 75 works so well, we're contempleting doing away with pre-emergents on established accounts with no crabgrass.
Pre-M adds $.50/1000 or more to the cost of fertilizer, Dimension even a little more.
Seeing Drive is only 2.00/1000 and you treat less than 2% of an average site, significant cost savings can be realized if performed properly and selectively.
08-26-2000, 07:58 AM
Just a side note, I treated my own lawn with a liquid app of Trimec Plus, along with the sedge and clover it also killed the crabgrass. Maybe a spot treatment this time of year may be what the doctor ordered.
08-27-2000, 11:06 AM
I've had the same problem with crabgrass this month also. I have always used split applications of Pre-M, but this year I tried something different, and used a high rate, and only one application. Don't think I'll do that again. Have just started using Trimec Plus, and it has done a good job on the crabgrass as well as Dallasgrass and Johnsongrass. I have tried Drive to spot treat, but I must have done something wrong, 'cause on the warm season grasses, all I did was shoot holes in the yards.
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