I cut down a 25 ft juniper tree for a brush pile. I read that fish wont use an evergreen til all the sap and leaves are gone so I uses hedge trimmers to remove all the green and small twigs that I could hang up on. How long will it take for fish to start using this pile. I sunk it over a month ago. Also I read that hardwoods (oaks, mesquites, etc.) are better for piles than are evergreens. Is this the case? The lake I fish is Ft.Phantom and has a mud bottom and almost no brush that hasn't been planted with the exception of some stickups in the southern end so I know brush piles will attract fish. If I make piles at different locations on the lake should I sink them in a bunch of different depths? How deep of water is a good depth to plan on being able to catch fish of the pile year around?

When I lived at Lake Somerville I sunk many large cedar trees. We sunk two big green cedars side by side one day in a cove. The next day was so windy that the only brushpile protected from the wind was the new one. We were sure it would be a waste of time but we wanted to fish so we decided to give it a try. Much to our surprise, the crappie had already moved in.

Fish can move in very quickly, or take a while, or both. Don't worry about the "myth" that it takes longer for fish to find brush. It just depends on the location of the brush. I'd recommend you sink brush in several different areas of the lake so that you always have an area to fish, no matter the wind, or time of year.
There are not many brush piles that crappie won't end up on sooner or later

If fish move to a new pile quickly, I think that's a good indication it's in the right spot. I don't know of any depth for brush that will produce year round. Brush in 8-12 ft will produce March-Oct. After that, you need to be fishing deeper in the lake or up creeks if there are some deeper holes that hold bait fish.