Crabgrass Concerns?

 Late summer is when Crabgrass has reached its peak growth and is the most noticeable to golfers.  This golf course has never been crabgrass free, but I do agree that we are seeing much more crabgrass now than in the past.  Crabgrass is a summer annual weedy grass that germinates from the prior year’s seed.   This means that as you get more and more adult plants the seed production increases leaving you with a greater challenge for the next season.  The only good thing about the crabgrass plant is that it quickly dies when colder temperatures come and the first frosts of Fall arrive.

We treat the golf course every year with a pre-emergent crabgrass prevention chemical and in the past couple years it has only proven to be only marginally effective.  We also have a product that can treat the crabgrass after it has emerged but we can only achieve success with this chemical if it is used when the plants are very small and just appearing in the grass canopy sometime in late June.

I realize that crabgrass is very ugly and no one wants to see it on the golf course.  Unfortunately, there is not much we can do to the mature plants without hurting the bentgrass this time of year.  What we can do is re-evaluate our spray program and make some changes for next year.  We have a plan to spray a split application of pre-emergent herbicide next spring to increase the window of time the chemical can be effective; we also plan on using a post-emergent herbicide product to kill anything that comes through in June/early July.  I feel that this strategy will yield much better result than we are currently experiencing.

The crabgrass will soon be turning purple when we get some cooler nights.  Then it will slowly fade back into the turf canopy and out of sight.  The seeds will stay dormant in the soil until the soil temperatures start to rise again in the Spring.  This is when we can start to wage the battle against the crabgrass.  It will be a never ending fight but I think that with the proper tactics in place we can make a large difference next year.

Thanks,

Josh Laughridge