Tree · Pinaceae
Norway Spruce
Picea abies
Tough, fast, and cold-hardy down to -40°F (-40°C), the Norway spruce grows into a towering evergreen with sweeping, pendulous branches.
Full sun
Every 7–14 days
USDA 2–7
39–59 ft · 12–18 m
Overview
Norway spruce is the big, fast-growing evergreen that stands in windbreaks, screens, and old farmyard plantings across the cold north. It came from Europe and now grows through temperate gardens far past that home range, quick to gain height and hard to faze with weather. On a mature tree, long gracefully drooping branchlets dangle in curtains from limbs that sweep upward, so the outline reads soft and weeping even from a distance.
This is a tree of real bulk that needs space and patience. It clears 100 feet in the wild and holds 40 to 60 feet in a yard, its broad pyramidal crown tapering to a point over a shallow root system that spreads wide instead of plunging deep. From the upper branches hang the long cones, the largest borne by any spruce, slender and pendent against the dark green. Give it room and it stands as a landmark; press it to a house and it crowds the wall within a decade.
Its defining trait is plain toughness. It endures brutal cold, roots into a range of sites, and holds its needles against the needlecast and canker diseases that thin fussier spruces. Keep its feet moist and its crown in the sun, and it asks for almost nothing else.
Care
The short version: full sun, moist but well-drained slightly acidic soil, and plenty of elbow room. The tree is cold-hardy and low-maintenance once established, needing little feeding and only light pruning.
Light
Norway spruce holds its densest, deepest-green needles in full sun, packed thick with light all day. It will take some partial sun, but a shaded tree grows thin and open, its branches gapping, and strong sun also keeps the needle diseases from taking hold.
Water
Keep the soil consistently moist but well-drained, soaking it deep while the tree roots in and through any drought. It bears neither extreme, sulking in soggy ground and browning on hot, dry sites, so water roughly every 7 to 14 days when rain runs short.
Soil
Set it in moist, well-drained, sandy loam on the acidic side, ideally a pH of 5.0 to 6.0. It roots into a fair range of ground but resents heavy, waterlogged clay, where its shallow roots cannot draw breath.
Temperature
Few trees stand the cold as this one does, its needles holding from -40°F to 95°F (-40°C to 35°C). It grows fullest in the cool north and thins where summers run long and hot.
Humidity
Ordinary outdoor humidity suits it, so no figure applies. Air movement counts for more, since still, crowded air among the branches invites the needlecast fungi that thin stressed trees.
Feeding
An established Norway spruce rarely needs feeding and holds its color on its own in decent ground. If new growth shortens, a balanced slow-release feed in spring is plenty, and rich soils may want none at all.
Pruning
Keep pruning to a minimum, taking out dead, damaged, or crossing branches in late winter. Never top the tree, since that cuts away the tapered point that gives it its shape. If a weevil kills the leader, train one straight side shoot upward in its place.
Repotting
none
Size & spacing
This is a forest giant in the making, rising 40 to 60 feet (12 to 18 m) tall and spreading its lower limbs 25 to 30 feet (7.5 to 9 m) across. Plant it well clear of buildings, drives, and utilities, since its shallow roots run wide and the crown only broadens.
When to plant
A spruce keeps no harvest clock, only a window to set its roots in the ground. Plant in spring or early fall so the roots take hold before the heat of summer or the deep freeze of winter, and the tree is hardy enough for the coldest ground, down through zone 2.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: spring or early fall
Hardiness
USDA hardiness zones: 2–7
Temperature: down to -46°C
Troubleshooting
A healthy Norway spruce rarely falters, and most of what goes wrong traces to a tree left stressed or crowded. Watch the topmost shoot and the needles deep in the canopy, since the first marks show there. Match what you see below, then act before a setback spreads.
The top shoot browns, wilts, and curls into a shepherd's crook
When the topmost shoot droops brown and limp and curls over into a tight hook, the white pine weevil is at work, its larvae tunneling down inside that leader until it dies. Cut the dead, hollowed leader out below the damage in mid to late spring, before the adults chew their way free, then train one straight side shoot upward to stand in as the new top. Cytospora canker can brown a branch or leader in much the same way, so inspect the wood closely when the weevil is not the cause.
Fix:
- Prune out and destroy the infested dead leader below the damage in mid to late spring before adults emerge
- Train an upright side shoot to become the new leader
- Maintain tree vigor with adequate water and mulch
Inner needles flush purple-brown and fall from the lower branches up
When the older needles deep inside the canopy turn a dull purple-brown and let go, bare patches climbing from the lowest branches upward, Rhizosphaera needlecast or a close relative has taken hold on a stressed tree. Under a hand lens the cast needles betray it: neat rows of tiny black dots line the surface where a healthy needle wears crisp white waxy specks. Open the crowded interior for air, water down at the roots, and cut away the worst branches, since dry roots and stress only widen the browning.
Fix:
- Improve air circulation by spacing and removing competing vegetation
- Avoid overhead irrigation and wetting foliage
- Remove and destroy heavily infected branches
- Maintain consistent soil moisture and mulch
Needles turn stippled and bronze under a haze of fine webbing
Needles freckled with pale stippling and gone dull bronze, strung with threads of fine webbing, mark the feeding of the spruce spider mite through the cool weather of spring and fall. Tap a branch over a sheet of white paper and the tiny specks drop and creep, confirming the pest at a glance. Wash the mites off with a hard jet of water first, keep horticultural oil for the times numbers climb, and pass over broad-spectrum sprays that kill the predators keeping the mites thinned.
Fix:
- Spray foliage with a strong jet of water to dislodge mites
- Apply horticultural oil or an approved miticide when populations are high
- Avoid broad-spectrum insecticides that kill mite predators
Toxicity
Good news for a home with pets and children: Norway spruce is not toxic. The one real hazard is mechanical, since the stiff, sharp-tipped needles are firm enough to prick skin, and a mouthful of swallowed needles might bring a passing stomach upset. Nothing in the tree will poison a cat, dog, or curious child.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
No poison sits in these needles. A cat that swats or nibbles the sharp, stiff tips may drool or paw at its mouth from the prick, and nothing worse follows.
Dogs None
A dog meets no true poison in this tree. The rigid, pointed needles can scratch a curious nose, and a swallowed mouthful may bring a brief stomach upset.
Horses Safe
The stiff, prickly foliage is no toxic browse for horses. They tend to pass it by, and a stray taste of the sharp needles does no harm.
Rabbits Safe
Rabbits can live alongside this tree with no risk, since its needles carry nothing poisonous to them.
Livestock Safe
The needles poison no cattle, goats, or sheep. Some conifers spell herd trouble, but this prickly foliage stays off the danger list.
Birds Safe
The dense, needled branches shelter birds and hold seed for them. Nothing in the tree is toxic to them.
People Safe
The tree poses no poison to people. Its sharp needle tips can prick bare skin, so handle fresh, stiff branches with care, but the wood and foliage are not toxic.
Needles are stiff and prickly and can poke skin; ingested needles may cause mild mouth or stomach irritation or, in quantity, GI obstruction, so discourage chewing.
Varieties
Beyond the towering wild tree, Norway spruce has thrown off a run of distinct cultivars, from weeping giants to squat little dwarfs. These are the ones worth knowing by name.
'Pendula'
A strongly weeping form whose branches drop in sheer vertical lines, staked upright as a dramatic accent or left to pool across the ground as a cover.
'Nidiformis'
The bird's nest spruce is a slow, low dwarf of only a few feet, its short branches fanning flat around a shallow, nest-like hollow sunk in the center.
'Acrocona'
This small, irregular, often semi-weeping tree hangs bright red-pink young cones from its branch tips, glowing against the dark needles.
'Cupressina'
A tight, narrow column of steeply upswept branches, it holds its shape under snow load and stacks a tall, slim spire into a small space.
How to propagate
How you raise more Norway spruce follows what you want: the wild tree comes true from seed, while the prized weeping and dwarf forms, with their odd shapes, have to be cloned.
SeedModerate
Sow stratified seed in spring · 2 to 4 years to a transplantable seedling
Seed gives back the true wild tree rather than a named cultivar, which will not come true this way. Chill the seed about a month in cold, moist stratification before a spring sowing, then wait out the slow green thread of a seedling, since it takes 2 to 4 years to reach a size fit to transplant.
GraftingDemanding
Late winter under cover · 1 to 2 years
Grafting holds the dwarf and weeping cultivars like 'Pendula' and 'Nidiformis' true to their odd shapes, the scion bound onto seedling rootstock in late winter under cover. The joining is exacting, but a clean union knits and grows on within 1 to 2 years.
LayeringModerate
Spring · 1 to 2 years to root
Prostrate and weeping forms layer where their low, trailing branches press against the soil and strike root at the contact. Peg one down in spring and roots form over 1 to 2 years, ready to be cut free and lifted once anchored.
Myths
Norway spruce and Colorado blue spruce are basically interchangeable.
Set the two side by side and the differences run deep past the look. Norway spruce grows faster, takes heat and mixed sites in stride, and shrugs off Rhizosphaera needlecast and Cytospora canker far better than blue spruce. For a tougher, longer-lived landscape tree, Norway spruce is the safer bet.
Spruce Christmas trees are poisonous to cats and dogs.
Spruce is no true toxin. Its chewed needles are at most mildly or mechanically irritating to the mouth and stomach, and the real worries are a passing stomach upset or, in quantity, a blockage. The hazard is the sharp, stiff, indigestible needles, not poison.