Mowing your grass regularly, especially if you’re mowing close to the ground, can help kill Johnsongrass. Frequent mowing helps limit the spread of Johnsongrass and can even deplete carbohydrate reserves in rhizomes over time. The more time you leave in between mowing, the more likely Johnsongrass is to regrow and take over your lawn. 

Mowing is one of the most important ways to maintain your lawn because it encourages grass to grow horizontally, creating a fuller, more uniform yard. On top of mowing your lawn, you’ll want to routinely fertilize your lawn, water it regularly, and take care of pests the moment they arise. 

Vinegar is known to be a contact herbicide, which means it kills the foliage it comes in contact with. Because of the high acetic acid concentration, horticultural vinegar kills weeds and grass more effectively. However, keep in mind that high amounts and multiple applications can affect the soil by lowering the pH levels.

If you spray a DIY vinegar solution that contains high salt, it can disrupt the soil's structure and make it difficult for plants to grow. That's why it's vital to avoid spraying vinegar solution on areas where you are trying to grow plants and flowers. When using a mix of vinegar and soap, some say you can plant a few days after the vinegar dries.