Andromeda, also known as bog rosemary or Japanese andromeda, is a flowering evergreen shrub. The plant produces gray-green leaves with a powdery texture and small flowers. The plants can reach up to 6 feet high and wide, and the shrub maintains an attractive natural shape. Older andromeda plants may need trimming to keep the plant's size in control or may need more aggressive pruning to invigorate old branches.
Deadhead the old andromeda throughout the flowering season by removing flowers as they become spent. This will invigorate the plant and encourage new growth.
Wait until the plant is finished flowering to begin pruning the stems. Use sharp gardening shears to remove any dead or damaged branches by cutting them back to the plant. Remove any stems that show signs of disease or insect infestation.
Cut back any branches that are growing faster than the rest of the plant, which disturbs the shape and may cause an older andromeda to look overgrown. Cut the tips of these branches back to meet the length of the rest of the plant.
Cut back all young stems on old and unruly andromeda plants that need complete reshaping. Cut the stems back to the trunk of the shrub, leaving the largest and strongest wood branches. Trim those branches back to your desired height, making all cuts above a leaf or flower bud.