I have built a work shop in my back yard, I want to put a sub box in the shed.
The shed is 2 1/2 ft. from my main breaker box. I plan on putting a 100 amp
Breaker in the main box to feed the work shop sub box. The sub box will have
Separate c/b's for all the circuit's but no main breaker. My question is do I have to have a separate grounding rod for the sub box even though the grounding rod for the main box is just outside, or can I use the same rod as the main box? If I must use separate rod how far apart do they have to be?

Sorry, you need a separate Grounding rod and EGC.

Ok, How far apart do they have to be? Or does it matter?

I'd say it's the AHJ (Authority Having Jurisdiiction) call. Personally, I think the separate ground rod isn't necessary, but it's not my call to make.

I might consider a panel with a main breaker. The main one in the shed would act as a disconnect and your allowed to have two. The shed's breaker CAN be higher than the feeder.

I'm with KISS. You certainly CAN use the existing rod if you can reach it.

You DO need a disconnect in a detached structure with a panel. A main breaker panel is by far the easiest way to achieve this.

Thanks for all the replies I think I will use the existing grounding rod. (kiss)