Q. How to prune a clivia?
Are you pruning your clivia to remove the faded flowering parts or to divide the offsets and propagate new plants? Clivia's can grow quite large, but are not usually pruned in any way to control height. To reduce fullness, you can divide the offsets as you would for propagation.
To remove flowering parts, first cut off the emerging fruits left after flowers fall with a clean razor to reduce plant energy diversion to fruiting. Once the flower stems dry up, pull them away from the plant.
To divide offsets from the plant for propagation (or to reduce congestion), begin by removing the plant from the pot right after the last flower has faded. For propagation, use offsets that have at least three of their own leaves of a length greater than 8 inches. Look carefully at the base of the plant to determine the point at which the offset attaches to the parent plant and use a disinfected, sharp knife to cut the offset with some significant roots away. (The roots are delicate and should be handled with care so as not to destroy them in the process.)
Plant the offset in a small pot with equal parts peat and perlite as a potting mixture. Keep this young plant warm, in light but away from the direct rays of the sun, and water sparingly until roots begin to appear above the soil. At this point you should move your plant into conventional potting mix in a slightly larger pot and care for the plant as you would a mature clivia.
I hope that helps!