Crabgrass is one of the worst type of weeds homeowners can have because it spread very easily. The early spring is usually when crabgrass spreads and becomes noticeable. Crabgrass is an annual grass and one of the first weeds that will pop up and appear in your lawn. what you want to do is in the very early spring, maybe even the end of the winter, you want to go and buy a crabgrass preventer. A crabgrass preventer is basically a preemergent chemical, preventing grass seeds from germinating in your lawn. It is really important to put this down early. If you put the crabgrass fertilizer on your lawn, you can keep the seeds from germinating, and at the same time help to fertilizer lawn. (Tip: Starter Fertilizer for Lawns often contains a crab grass preemergent.)
You can also prevent crabgrass just by having a very thick and healthy turf. New grass seed will have a hard time growing if the existing grass is already thick and hearty. If they never have a chance to seed, they will be gone next year. If you start to notice one or two places in your lawn where crabgrass is growing, take a shovel to them right away and dig them out. Make sure the you get rid of the roots so that the crabgrass will not grow. Then, take good grass seed and feel and the patches so that you can keep crabgrass out of them in the future.
Tiny annual grasses, like “po-Anna” are extremely difficult to get rid of. This is because they seed below the height at which you cut your lawn. Every time you cut your lawn, you can spread this seed quickly. On golf courses they even have a type of poison designed to combat this crabgrass specifically. However, the cost makes it a bit on the expensive and for the average homeowner. (About $120 a quart)
If you want to keep from having a problem with crabgrass, make sure that you inspect your lawn carefully the first time that you mow it in the spring. If you notice crabgrass, try to dig it out right away. If you tend to get crabgrass on a yearly basis, use a crabgrass preventer to keep it from coming back. Most of the time crabgrass grows very quickly and it can take over your lawn if you are not careful about it. Once it takes over your lawn, there is usually no way to get rid of it, except for spraying Roundup on the areas that are affected, and then digging them out.
If it is very extensive, you may have to kill crabgrass with Roundup. After it dies, have the lawn power raked, and then roll on new sod.