Very carefully. You should be cautious when using any of the above methods, as any one of them could lead to you accidentally killing desired grasses and plants. However, there are selective herbicides that can target certain plants over others. Look for a product that only affects the type of weeds you want to eliminate and spares the plants you want to keep.

The fastest ways to kill weeds and unwanted grass include burning them, pouring boiling water on them, or pulling them out by hand, as these methods work almost instantaneously. For a quick-acting solution that works within a few hours, you can use a commercial-grade herbicide like glyphosate or a DIY vinegar, salt, and dish soap mixture. While effective, be aware that commercial herbicides introduce chemicals into your lawn. The slowest method for killing weeds is to starve them of sunlight and nutrients using mulch or fabric covers.

It’s not legal to intentionally damage a neighbor’s tree. Even if the roots of a tree encroach into your yard, if you damage or kill a tree that belongs to your neighbor, you can be held liable for the damage in most cases. Since herbicides can spread through the tree, causing damage to the whole tree and not just the roots that are on your side of the property line, you shouldn’t poison your neighbor’s tree. The other downside to this method is that if the tree dies, it can fall onto your property and cause more damage, so herbicides are best avoided in this circumstance.

Look for a broadleaf herbicide, one that has been formulated specifically for dandelions and is considered grass-safe.