The best way to prevent weeds is to use polymeric sand, which hardens and blocks weed growth when activated with water. If you're using regular sand, you'll need to refill and compact it more often. Keeping the surface clean and free of debris can also help prevent weed seeds from settling in the joints.

You should add 1 to 4 inches of mulch, depending on your garden type and needs. Keep in mind that no amount of mulch can completely prevent weeds, but a heavier coverage (closer to 4 inches) can suppress weeds enough that you are only seeing them sprout every few weeks. Finer mulch prevents weeds more effectively than large mulch, so if you’re using mulched leaves or shredded bark, 1 to 2 inches will likely suffice, while 3 to 4 inches is best for larger mulch, like bark chips or straw.

Clover lawns stand up better against dog and cat urine than traditional turfgrass. If your pets love to hang out on the lawn on a sunny day—or if you find yourself with a lot of visiting neighborhood dogs—you could save yourself from yellow and brown patches by making the switch to a clover lawn.

Some of the particular herbicides that work best to get rid of nut grass without killing the grass include Halosulfuron-methyl, mesotrione, sulfentrazone, and metsulfuron. A herbicide like glyphosate would kill nutgrass, but it will kill nearby plants, too.