The main features of the pyracantha shrub are heavy clusters of bright red or orange berries that mature from late autumn to early winter. Light pruning or thinning is necessary to maintain the shrub's shape. However, new growth should also be cut back to encourage berry production. Berries develop on growth from the previous year, so branches bearing previous growth should not be heavily trimmed. Prune late in the spring when the new flowers have begun to bloom. Protective measures are necessary when cutting back a pyracantha because the plant's sharp thorns can leave painful scratches or cuts.
Cut back any dead, broken or overgrown woody limbs that are more than one-half inch in circumference. Wearing protective gardening gloves and goggles, use the long-handled hedge clippers to cut the limbs back to the nearest intersecting branch.
Cut any long limbs that have been removed into smaller sections before disposing of them in the trash.
Cut back dense, non-flowering new growth, or thinner branches, using hand shears. Try to cut back any new growth that is covering berry clusters.
Trim the ends of longer branches if shaping the shrub,. Take care not to remove too many flowers, or new berry clusters.
Cut back any obviously non-flowering branches to allow more air and sunlight to reach interior areas of new growth. Dispose of all cuttings carefully.
Annual thinning for at least three years will encourage increased berry production.
Do not remove too much flowering new growth - that will bear next year's fruit.