We have a large Hibiscus growing in the front garden. We want to trim
it back now that the blooms have stopped, and eventually move it to
another location, possibly splitting the root pack. When can we trim
the stems back and how far can we cut? When is the best season to
transplant to another location in the garden?
Hardiness Zone: 7a
Richard McCormick from Bristow, VA
Early fall is the best time to minimize transplant shock. This is when the plant starts to cycle down for the winter and the focus is diverted to root growth. Moisten the soil first so you can dig the plant with as much soil attached to the root system as possible. Wrap the roots in burlap or plastic as you move the plant. Since you mentioned you're already growing your plant outdoors, I'm assuming you are growing a hardy variety, as tropical varieties would need to be brought indoors in your zone.
In regards to pruning: Cut the longest 1/3 of the total number of branches back by 1/3 in length. Wait at least 30 days and cut the next longest 1/3 and so on. This light pruning will eliminate the need for heavy pruning. Do this pruning after the plant starts to cycle down for winter or early in the spring (February/March) before vigorous growth starts again. Keep in mind the overall shape of the plant and the direction you want the new growth to occur. Choose leaf nodes (eyes) that are pointing in an outward direction and leave 1/4 inch of wood above each leaf node when making cuts.