CRABGRASS GERMINATION?

May 2, 2013

It is May 2 and we have a snow storm going on in Ames.  Normally, when people ask me for a date by which they should have their preemergence herbicide applied for crabgrass control, my standard answer is to have it down by May 1.  The question that I have received most often in the last two days, is whether this cold weather will delay germination. 

The expected answer would be that the cold weather will delay germination,  however, I have been watching crabgrass germination dates for 34 years here in central Iowa.  What I have observed is that the germination date does not vary much from year to year.  When we have a warm spring and you would expect early germination, the crabgrass still germinates about the same time (around May 1).  When we have a cold spring, like this one, the crabgrass still seems to germinate about the same time.  It may be a few days early or late, but not a few weeks.

I am still expecting crabgrass to germinate soon.  If you do not have your preemerge down, I would recommend applying it as soon after the snow melts as possible.  I put mine on last week.
 

Horticulture Hall

Horticulture Hall

Horticulture Hall

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Nick Christians Professor

Nick Christians, Ph.D. – University professor of turfgrass management, Iowa State University, Department of Horticulture, Ames, IA, and adjunct faculty, Department of Agronomy, Iowa State University, Ames, IA. Dr. Christians received his B.S. from the Colorado State University ...