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.

A spot herbicide for weed control is effective at killing crabgrass and not grass, but it depends on the type of herbicide. Always check the label to ensure that your herbicide is safe for grass but tough on crabgrass. Overall, spot treatment is ideal because it puts fewer herbicides into the soil, which can damage the soil. If you’re wanting a natural remedy to crabgrass that also won’t harm surrounding grass, you can also hand-remove crabgrass or even pour boiling water or 5% vinegar over crabgrass as a spot treatment.

Yellow patches, poor growth, or widespread weeds indicate a need for treatment. Soil testing can confirm nutritional deficiencies that require intervention.

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.