Hedges can serve an important border and privacy function in your home garden, in addition to adding to your overall garden aesthetic. Even if your hedges are all-weather tolerant, healthy and hardy, harsh chemicals can still damage them. There are several household ingredients that when purposefully or accidentally spilled or applied to hedges, will kill the hedges.
Bleach is a very caustic material and can seriously damage and kill most plants and trees, including hedges. Whether you are using a bleach solution to clean clothes or an outdoor pathway, be careful not to discard or spill the bleach on your hedges, as it will quickly kill them. If you want to purposefully kill unruly hedges, pour bleach onto the hedges' roots. Keep in mind, however, that you will most likely kill all other plants, including grass, in the area.
Salt is another powerful plant and weed killer. If you are trying to kill weeds in the same soil that your hedges are growing, be careful when you use salt, as it can also damage or kill your hedges. On the other hand, if you want to kill your hedges in order to remove them, salt may be a good option. Dilute salt with water and spray a solution near to your hedges' roots. After several applications, your hedges' roots will begin to die. Be careful not to get any of the salt solution near your other plants, trees or even grass, as it can damage or kill those as well.
Vinegar has been proven to be an excellent cleaning substance, but like bleach, it can easily damage and kill hedges. Vinegar in low concentrations can be used on hedges as an organic herbicide. But in higher concentrations (over 30 percent) it can kill your hedges. If your purpose is to kill your hedges using vinegar, spray a high concentration of vinegar around the hedges' roots, but be careful not to spray other plants that you do not want to kill.
If your desire is to kill your hedges without damaging other area plants, you may want to use a simple, copper nail. The chemical reaction between the hedges' roots and the copper in the nail will result in the death of the plant. Find a root of the hedge (the bigger or more central the root, the more effective) and hammer the copper nail deeply into the root. The hedge will eventually die.