In early spring …
Don’t forget knotweed germinates before crabgrass.
So if you see germinating seedlings, it is probably knotweed.
Remember that knotweed is a summer annual broad-leaved weed.
It germinates fairly early in the spring … earlier than crabgrass.
At this time of year, people are concerned are concerned about missing the opportunity to get their pre-emergent herbicide down because they see all these young seedlings, assuming they are crabgrass.
Most of the time, they are knotweed.
Look closely at the leaves.
When it germinates, knotweed has two small leaves like grass leaves, but shortly after germination, the leaves begin to get wider and take on that normal broad-leaved weed shape.
A pre-emergent herbicide is not normally recommended for controlling knotweed.
It is best to try and alleviate compaction, reduce traffic, and increase the density of turf by seeding and fertilization, as well as use a post-emergent broad-leaved chemical to control it after it is done germinating.
Nonetheless, crabgrass itself will be germinating very very soon.
For a copy of the original A Look At Report, WITH PHOTOGRAPHS, go to the following link …
For more on TURF and ORNAMENTAL MAINTENANCE , NORAHG has archived information on the following web-pages …