White Spruce (Alberta Spruce, Black-Hills Spruce, or Cat Spruce)
Picea glauca (PINACEAE)
Planting and Growing White Spruce Trees
You’ll find everything you need to know to plant and grow white spruce trees in the accompanying table’s tabs:
-
- Foliage, cones, and seeds of white spruce trees
- Growing conditions for white spruce
- When to plant white spruce
- How to plant white spruce
- How to prune white spruce
- Watering, fertilizing, and care of white spruce
- Landscape uses of white spruce
- Pest and disease control for white spruce
Growing White Spruce Trees
Many cultivars of fast-growing, upright, pyramid-shaped, coniferous, evergreen trees, to 100 ft. (30 m) tall, with whorled, nodding branches, and radiating, shiny, deep blue green, stiff, sharp needles, to 3/4 in. (19 mm) long, and with blue green bark.
White Spruce Planting and Care Guide
Flowering and Cones
Male cones resemble feathery catkins, 1–3 in. (25–75 mm) long; female cones are dangling, oval, and pointed, to 2 in. (50 mm) long, with scales and single-winged seed.
Best Climates
U.S.D.A. Plant Hardiness Zones 1–9. Hardy. Somewhat heat tolerant.
Soil Type and Fertility
Damp to dry, well-drained soil. Fertility: Rich–average. 5.0–6.5 pH.
Where and How to Plant
Full to filtered sun. Space 10–15 ft. (3–4.5 m) apart.
Proper Care
Easy–moderate. Allow soil surface to dry between waterings until established. Avoid fertilizing. Prune only to shape in spring, removing half of new growth “candles.” Propagate by cuttings, seed.
About This Species
Good choice for accents, screens, specimens, windbreaks in meadow, woodland gardens. Maturing trees shade underfoliage, causing needle loss. Aphid, spider mite, gypsy moth, tussock moth and canker susceptible.
Common Species and Cultivars of Spruce
Spruce Species:
-
- Picea abies, Norway spruce
- Picea brewerana, Brewer weeping spruce
- Picea engelmanii, Engelmann spruce
- Picea fraserii, Fraser spruce
- Picea glauca, white spruce
- Picea mariana, black spruce
- Picea pungens, Colorado blue spruce
- Picea sitchensis, Sitka spruce
Popular Cultivars:
-
- Picea glauca var. albertiana, Alberta spruce
- Picea glauca var. densata, Black Hills spruce
- Picea pungens ‘Glauca’, blue spruce
- Picea pungens ‘Pendula’, weeping blue spruce
About Spruce Trees
The Picea genus, with its 45 species of firlike, large and stately, pyramid-shaped conifers, is native to the cool, temperate mountains of the northern hemisphere. Spruces can be distinguished from the firs by their large, dangling cones and stiff needles. They are excellent trees for use in full-sun, open landscapes where their tall form and upraised branches may be appreciated.
Spruces are easily recognized in the garden because of their arrow-straight, conical form; whorled branches; rigidly stiff needles; and large, dangling cones. When mature, they have straight, limbless trunks and open crowns, traits that made them the tree of choice for wood used for sailing ship masts throughout the 19th century.
Spruces need mild, moist summers and cold winters to thrive. Avoid planting them in lowland gardens with hot, dry summers and mild winters.
All are medium- to slow-growing trees, eventually reaching 75–150 ft. (23–45 m) tall. Many dwarf cultivars have been hybridized, making them ideal for growing in containers in small-space gardens. When kept rootbound in a planter, they grow slowly and are ideal for bonsai and shape training. They otherwise rarely need pruning.
Spruces are sometimes susceptible to aphids, spider mites, and the larvae of gypsy and tussock moth. They also can contract cytosperma canker, which kills their inner, lower branches.
Choose from among the popularly cultivated species and cultivars, at left.
Planting and Caring for Spruce Trees
Since all landscape trees do best when they are planted in unamended soil, your site should be tested for acid-alkaline balance before planting. Spruces need soils in the 5.0–7.0 pH range; you should choose another conifer if your soil is too alkaline. You also should compare your tree’s needs to your U.S.D.A. Plant Hardiness Zone.
Plant all spruces in moist, well-drained, acidic soil.
Carefully match your planting hole’s depth to the soil line on the rootball of your tree when you plant. Spruces are shallow-rooted trees that need good drainage. Their root crowns should be positioned at the same level as they were grown at the tree nursery.
Backfill the planting hole with native soil, surround it with a moat, and water the tree often through its first two seasons, whenever the soil surface becomes dry. Water established trees in times of drought.
Choose spruces for open or woodland gardens. They grow slowly to become the dominant feature in the landscape, so plant them with ample space, especially near structures or paving.
To use a spruce as an indoor holiday decoration, plant it and its container in the soil, applying mulch over its roots. Unearth the tree before the soil freezes, clean its container, and bring it indoors. When the holiday season is over, the tree can be replanted in your garden.