Pinus thunbergii ‘Thunderhead’ Japanese Black Pine

‘Thunderhead’ is a shrubby, compact cultivar of Pinus thunbergia, the Japanese Black Pine, native to the coastal areas of Japan and South Korea. The cultivar was a seedling selected at Angelica Nursery in Kennedyville, Maryland, in 1987. Its attractive foliage and slow growth make it an excellent choice for enhancing small to medium spaces. ‘Thunderhead’ received the Royal Horticulture Society Award of Garden Merit in 2012 for its beauty and hardiness down to -4° F.
This little tree has dense, dark green needles 3.5″-4.5″ long and silver-white candles in winter and spring that stand out against the color of the foliage. Later in the season, 3″ long oval, brown cones form on the branches. The tree is irregular, spreading when young and maturing into a broadly pyramidal form. It grows 6″-9″ annually, attaining a height of 5.5′-6′ in 10 years, and at maturity, it can grow to 10′-15′ high and 8′-10′ wide.
‘Thunderhead’ grows best in full sun and in clay, silt, loam, or sand as long as it is moist, well-draining, and neutral to acidic (5.0-7.0) pH. It will not tolerate waterlogged, soggy soil and will die in standing water. Water the tree when you plant it, then an inch a week for a year. It will become drought-tolerant after it is established and will not require watering except during long periods of heat and drought when the top two inches of soil are dry. Pruning is not necessary except to maintain the shape or trim it into a topiary shape. Thunderhead Japanese Black Pine is an attractive choice as a specimen plant and for rock gardens, Asian gardens, containers, conifer groupings, and as a hedge or privacy screen. It is hardy in USDA zones 5 to 9.
In addition to its beautiful color, foliage, and slow growth, ‘Thunderhead’ is deer, disease, drought, and rabbit-resistant, and it is tolerant of salt and coastal exposure.
Companion plants will need the same growing conditions as this tree – moist, slightly acidic, well-draining soil in full sun. Trees like Japanese maple, dogwood, and redbud will provide a contrast of shape, color, and a loose, airy texture against the dense green needles. Colorful shrubs, such as weigela, barberry, euonymus, forsythia, and viburnum, are an attractive foil for the tree. For a mixed grouping, a columnar tree, such as Stowe Pillar white pine or Sky Pencil holly and a low-growing juniper would look well growing together with ‘Thunderhead.’