Choosing the proper time to prune holly bushes is crucial, as it can determine how well new growth will be able to thrive; for holly bushes, the best time for pruning is early summer. Pruning evergreen hollies after the growing region has had sufficient time to warm up after winter and has exited the frost/freeze timeframe allows the new growth that occurs after pruning the optimal chance for survival.
Depending on the variety of holly bush that needs to be pruned, the following guidelines may be helpful for determining which pruning techniques should be used:
- Deciduous hollies (winterberry, possumhaw): Radical pruning needed each year
- Rounded hollies (Japanese, Inkberry, Yaupon): Thinning needed during first few years of growth; formal shaping throughout life of the plant
- Indeterminate hollies (Blue, English, Chinese): Thinning and formal shaping throughout life of plant
- Pyramidal hollies (American, English, "Nellie R. Stevens"): Thinning, no formal shaping necessary