Crabgrass or Knotweed germinating, don’t panic!

I posted some pictures on Twitter over the weekend of some Knotweed germinating.




Remember that Knotweed is a summer annual broadleaf weed. It germinates fairly early in the spring…earlier than crabgrass (which germinates earlier than goosegrass). I occasionally get calls at this time of year where people on concerned they missed the opportunity to get their pre-emergent herbicide down because they see all these young seedlings like below and they assume it crabgrass. Most of the time is knotweed.  Look closely at the leaves.  When it germinates, it has two small leaves like grass leaves, but shortly after germination the leaves begin to get wider and take on that normal broadleaf weed shape.

I don’t usually recommend using a pre-emergent for controlling knotweed. It is best to try and alleviate the compaction, reduce the traffic, increase the density of turf by seeding and fertilizing and use a post-emergent broadleaf chemical to control it after it is done germinating.

But crabgrass is going to be germinating very very soon. Read more about it in this recent article.  So get your pre-emergent down soon.

Newly germinated knotweed. Notice how the young stuff looks like a grass. But the older leaves on the left are more wide and look more like a traditional broadleaf weed.


Be Sociable, Share!