XANAX (alprazolam) HAS a duration of action of up to 6 hours. If you want to know how long after you take it can it be DETECTED, that's different. Most benzodiazapines, when taken on a regular basis, can be detected in the urine from 24 hours to 72 hours.
The color of that mulch is a dark brown, browner than most brown mulches. I thought it was good mulch until I noticed how large the pieces were. They were similar to large chunks of wood more so than mulch.
There are many types of mulch in addition to grass clippings. There is no right answer when it comes to deciding which type of mulch to use. Instead, keep in mind your goals for the garden. If you simply want to prevent weeds from growing, an inorganic mulch such as rocks make for a decorative touch.