Manicured gardens are a thing of pride and beauty, but sometimes invasive or unwanted plants and trees crop up where they shouldn't. When this happens, choose one of several methods for killing plants and trees, either naturally or chemically. When deciding on which method to use, be sure to keep in mind that you could accidentally kill wanted plants.
Over- or Underwatering
Excessive watering of many plants is a sure-fire way to kill them. Unless a plant is aquatic or very tolerant of wet soil, too much water will cause the plant to die off. Novice gardeners often overwater for fear that they aren't watering their plants enough. On a similar note, neglecting to water plants, especially indoor plants that don't benefit from natural precipitation, will also lead to their demise. Few plants can survive very long without water, and denying a plant necessary water causes it to dry up and die.
Girdling and Paving
A method of killing trees specifically, girdling involves stripping the bark from around the circumference of the tree. When the bark is removed, the tree cannot disperse the food created in its leaves down to its roots. This method of killing a tree takes a few weeks to work. Similarly, paving over a tree cuts off access to the roots as well, which will eventually kill the tree completely.
Salt and Vinegar
Both salt and vinegar effectively kill off plants. Salt dehydrates plants when water is added, causing them to die. Vinegar, when mixed with water, can be sprayed onto plants and around the soil to soak into the roots. However, with both substances, care must be taken. Salt can damage the ground and make it hard for anything else to grow there for a long time. Vinegar may not corrupt the soil, but it may kill plants that you want to keep. To avoid this, surround the unwanted plants with some kind of barrier, such as a cut two-liter soda bottle, and spray directly within the area.
Getting rid of unwanted plants and trees can be as simple as digging into your household cleaners. Borax, WD-40 and bleach all prevent plants from growing and will kill them. Once the chemicals have killed the unwanted plants, dig them up and dispose of them to prevent them from rooting again. As with salt and vinegar, care should be taken to ensure that wanted plants aren't affected.