Crabgrass is a nuisance weed that looks like grass, but grows in clumps. It can quickly take over a lawn if you do not take care of it. Bermuda is also a nuisance if you are not using it in your lawn. It is a creeping grass that grows into unwanted areas and can choke out other grass. Removal of these two green plants can be done in a few different ways.
Cover the lawn, where the weeds and Bermuda are located, with light-blocking plastic. Put heavy objects on the plastic or hammer stakes through the corners to keep the plastic in place. This will keep light away from the vegetation, and it will slowly die. It will take at least one week to thoroughly kill the crabgrass and Bermuda grass.
Spray a non-selective herbicide on the lawn that will kill all vegetation. This will ensure that both the crabgrass and Bermuda are killed. For something more natural and safer for pets try vinegar. Be careful spraying either of these. If it gets on other plants, it might kill them as well.
Cut crabgrass out by the roots. This is a safe way to remove the weeds without harming other plants or buying any products. You can also dig out Bermuda coverage with a shovel and overseed with the grass you want. Bermuda is a surface grass--its roots do not go down deep.
Mow often. Crabgrass that is cut often will sometimes give up and die out. Mow before cold weather to speed along the death of Bermuda grass.