Nothing is a perfect match to natural aging but here is a trick I tried to accelerate the aging process: I lightly heated the wood's surface with a propane torch to help dry it out. This will cause it to darken slightly. Lightly mist some water on the surface, not enough to wet it and let it sit out in the sun for a week. It will not match up with weathered wood but it is a rapid start to the process and will not look like new wood.
"Living in the D" (this means Detroit!)
"It's fine to disagree with other members as long as you respect their opinions"