Picea alcoquiana

Alcock's Spruce
 

Mature Size, Growth, Longevity

A large evergreen tree, to over 80' tall, with a broad-pyramidal crown. Slender, horizontal-spreading branches curve upward at tips.

Native Range

Native to the mountains of central Japan. Discovered in 1860 by John Gould Veitch, during his ascent of Mount Fuji-yama, and he named it after Sir Rutherford Alcock, British Minister to Tokyo, and his companion on the expedition.

Flower and Fruit Details

Monoecious flowers. Ovoid, cylindrical cones, 2-5" long, purplish when young, ripening to dark brown color, leathery, with very small bracts.

Leaf and Bark Features

Evergreen: Needles 0.2-0.8" long, bluish-green to gray-glaucous. Needles 4-sided, with stomatic bands on each side. Winter buds slightly resinous. Bark is pale gray to grayish-brown, thin, and splitting into narrow, scaly strips. Smaller branchlets are a shiny, yellowish-brown to reddish brown, changing to gray after 3-4 years.

Culture and Care

Prefers average, medium moisture, well-drained, acid soils in full sun. Tolerates higher pH and clay, if not wet. Will tolerate light shade. Does best in cool-summer climates. Zone 3-7. Wind-tolerant. Possible problems include canker diseases, wood decay, needle cast and rust. Insect problems sometimes include aphids, scale, bagworms and mites. Resistant to Verticillium Wilt disease.

Strengths, Weaknesses, Other Facts

Good wildlife value. 4-season interest: Spring, Summer, Fall, Winter. Also known as Picea bicolor in the past. Good for songbirds.

Suggested Uses

Used as a specimen plant in the landscape.

Taxa and Plants of this Species at BCA

The following taxa are (or were) represented in the collections at Boone County Arboretum. Additional taxa may be available in the trade that are not included here.

  • Picea alcoquiana 'Howell's Dwarf' // Howell's Dwarf Alcock's Spruce, Howell's Dwarf Tigertail Spruce
    Shrub. A dwarf form, 3-8' tall and 5-15' wide w/ age. Rigid, somewhat prostrate branching, flat, spreading habit, with rigid branches. Upright shoots on older plants may be cut out to limit growth and prevent reversion to tree form. Tops of needles are green to bluish-green, with tints of yellow, while the undersides of foliage is a sparkling bluish-white to silvery-blue, especially noticeable in the winter. Purplish-red cones develop at an early age. Needs full sun. Zones 4-7. Use as a specimen plant or in rock gardens.
    Bed 14