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After the big rain we had, I hit the weeds–most of which involved wrangling ever expanding globs of crabgrass. Yes, this is the time when crabgrass rears its ugly head and begins to creep through our fescue lawns, sneak into our cultivated beds and, when we’re not looking, reseeds itself to ensure the continuation of the species. Okay, maybe a little melodramatic but my hands still hurt from all that pulling!
Since crabgrass is an annual grass, it is all about seed. Pre-emergents in the early spring will certainly help, but, what many people neglect to do is to reapply the control every 6 weeks. Pre-emergents prevent seed from germinating but the active ingredient only remains viable in the soil for about 4 to 6 weeks. We will use corn gluten as a pre-emergent in our trouble spots to augment our other weeding efforts.
A little elbow grease goes a long way. When you see a clump of the light green blades begin to creep through the fescue, pull it up. With all the moisture in the soil (for most of us), you will find it quite easy to “weed” small patches of crabgrass. Gingerly pull the creeping blades that have developed roots out of their entanglement with your fescue. Once you have loosened these, you can better grip the main, center roots and pull it right out. Reseeding of bare areas after the crabgrass is removed can be done at the end of the month.
For more significant crabgrass problems, you will need to apply a herbicide labeled for crabgrass. As much as I hate using pesticides this is where you may have to break the rules to manage the problem. Products are most effective when the crabgrass is in the earlier stage of growth. Apply 2 to 3 times at 10 day intervals. Continue to use pre-emergent controls to prevent any existing seed from germinating. Getting it under control usually takes several years of using control methods and proper mowing techniques. Don’t mow the grass too short and fertilize in the fall of the year to encourage healthy fescue. Once you get your lawn back, don’t continue with bad habits!
You may be quite surprised at the history of crabgrass and how it was first introduced in the United States. Actually it came across the ocean with immigrants from Europe who had cultivated crabgrass for the seed. Crabgrass seed was used like millet.....a common ingredient in porridges and breads. When its use in the kitchen declined due to the more efficient crops of corn and wheat (it took 100,000 crabgrass seeds to make a pound), crabgrass was used as cattle fodder. As the native summer fodder browned out, the green crabgrass proved appealing to cattle. Our sheep like it so I don’t mind a little out in the pastures; but, we are still battling it in mulched areas and walking paths.
Crabgrass declined in use as fodder by the turn of the century but the invasive grass had already planted its seed. In a relatively short period of time, crabgrass has spread throughout the entire United States. Once we started to have manicured lawns, crabgrass really went crazy. It was more noticeable for one thing; but, more than anything else, the fact that we were mowing our lawns short meant that the crabgrass seed could make contact with the soil at a much higher percentage (that’s one of the reasons why you should not mow shorter than 2 1/5 inches). Yet another lesson in how human activity can change the environment of a continent!