The main problem with crabgrass is that it produces thousands of seeds that can remain dormant until the following season. To get rid of it, you have to remove existing plants before they have a chance to spread seeds and stop old seeds from germinating.

There are several ways to kill poison ivy permanently. The trick is to keep it from coming back. Herbicides and natural remedies are highly effective for killing existing poison ivy plants. However, plant and root parts left behind can easily create new sprouts that turn into full-grown plants. The only way to permanently get rid of poison ivy is to be patient and diligent until all traces of the plant are dead and gone.

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. 

Poison oak is similar to poison ivy in that it's in the same family of plants. Poison oak is identifiable by its rounded-off leaves and hairy leaf texture. Tree-climbing varieties live primarily in western states while low-growing poison oak bushes occupy the eastern states. Treat poison oak like poison ivy to get rid of it permanently.