How to Prune large-leaved bog rosemary?
Shorten flowered shoots to about 1.5–2.5 cm from the previous year's growth. If flowering is on last year's growth, prune after flowering; if on current-year growth, prune the following early to mid-spring.

large-leaved bog rosemary · Andromeda polifolia 'Macrophylla'
Needs moist, acid soil in sun, part or full shade, suitable for shaded rock garden or damp shady border
Shorten flowered shoots to about 1.5–2.5 cm from the previous year's growth. If flowering is on last year's growth, prune after flowering; if on current-year growth, prune the following early to mid-spring.