Do i prune a mallow shrub.

Cut back large wood to buds and cut out small wood now.
In March if you live in the South or April if you live in the North, cut down to required height removing die-back and frost damage. feed, top dress with compost round root area.

These are fast-growing shrubs and can easily grow eight feet in a season. You can be really vicious with it in the spring, cutting it right down to a small stump

Thanks for your help.........Andrewr and Doctorbob1.......