Quackgrass is a weedy grass that probably gets its feelings hurt every time someone refers to it as "crabgrass". Crabgrass gets all the glory. It's understandable to confuse quackgrass for crabgrass because they have some similar characteristics, a coarse leaf blade and lime green color that causes it to look different from the rest of the lawn. Here's a picture of Quackgrass taken this spring.
If you see something that looks like crabgrass in the early spring in the midwest, you can be almost 100% sure that it isn't true crabgrass. Old Fashioned Tall Fescue is another grass that commonly is confused with crabgrass.
Who cares whether its crabgrass, Tall Fescue or quackgrass you ask? It's still ugly and you still don't want it right? Well, it matters because if you don't know what type of grass you're dealing with, it's difficult to know how to eliminate it. For example, pretend you see quackgrass in your lawn and assume its crabgrass, you might decide to apply a natural pre-emergent crabgrass product, or worse, a chemical crabgrass pre-emergent to get rid of it, you won't have success will have potentially used a chemical for no reason. Nobody is happy.
True Crabgrass is an annual grass that is only present in the lawn between June and October. I usually don't see it sprouting until late May or early June in Ohio. At that point it is young and not very objectionable. It doesn't get big and ugly until later in the summer. Here's a picture of crabrass before it gets too ugly.
Crabgrass is a summer annual weed that sprouts in the spring, flourishes during the summer, and dies in the late fall. The best way to eliminate true crabgrass is by thickening your lawn (seeding in the late summer/early fall), mowing high, and watering 1-2 times per week instead of daily. You can also apply an organic fertilizer that contains corn gluten meal like our early spring organic lawn fertilizer to help prevent new crabgrass seeds from germinating. Visit our website for more information about how to control crabgrass organically.
Quackgrass is actually more difficult to eliminate than crabgrass. Unlike crabgrass, quackgrass is a perennial that does not die each season. The best way to handle quackgrass organically is to overseed the area with desireable grasses, mow regularly, and fertilize organically to encourage the healthy grasses to outcompete the quackgrass. If it's really bothering you, you can spray the quackgrass with roundup (not organic) and reseed the entire area (the roundup will kill the grass too).