Just a thought, if you go with a MH fixture, try screwing in a clear mercury lamp of the equal wattage (if the ballast says it will operate a mercury lamp, most non pulse-start MH ballasts will). I say this because the non coated mercury lamps produce more green and blue light and may enhance the foleage on the tree, making it look a deep green colour.. Just my 2 cents..
A.D
