Thursday, December 31, 2020

Thunderhead Japanese Black Pine


'Thunderhead' Japanese Black Pine at U.T. Gardens in Knoxville
Thunderhead (Pinus thunbergiana) is a choice shrub variety of Japanese Black pine. This medium-sized evergreen shrub conifer grows 10 to 12 feet high and 12 to 15 feet wide (in 10 - 15 years). Its distinctive cottony terminal buds and dark green densely packed needles are architecturally beautiful in the fall-winter landscape.

“Billowy emerald clouds” best describes the needle foliage on Thunderhead pine.  Silvery white candles (shoots) grow 10 - 12 inches long in response to warm spring temps.  The shoots reach their full length by late May. Branches are rigid and its lower needles are mostly retained.
Desired location is in full to partial sun and in moderately acidic soils that are well-drained. Provide a minimum of 6 hours of sunlight. Plant in late winter to early fall from container or balled and burlapped (B&B) stock. Allow 1-2 years to become established after planting; afterwards drought and heat tolerant.

Feed annually in late winter with 10-10-10 or equivalent granular fertilizer. Pruning is rarely necessary except for desired shaping and sizing. Cut back new shoot growth (“candles”) around late May to early June before needles are fully expanded.

Disease and pest problems are rare when properly sited. Thunderhead is highly tolerant of wind, drought, and salt spray. Provide shelter from harsh winds to minimize off-color in winter. Availability is primarily from specialty conifer nurseries on-line or in the southeast region.

Thunderhead Japanese black pine is loved for its low maintenance and its dark evergreen foliage. This shrub pine conifer deserves a place in your landscape.