Don't know what zone your in, but if you're in zone 8 or lower it's not a good idea to trim sagos unless the fronds are completely brown. Cycads and palms pull nourishment from old fronds so cutting back will weaken the plant. If they're too tall you'll need to relocate them. The growth bud is at the top so if you cut it back into the bud you'll kill it. If there are pups around the base of the plant, that might be an option as the pups will eventually fill in for the mother plant.

Dose anyone know when and how to dig up and transplant my sago pups?