Spruce - Picea sp.
35 species of this evergreen are widely available in the US. Many
varieties are tall, conical to pyramidal trees, most familiar as a
popular Christmas tree. Some species tend towards globular growth, and
slow-growing spruces can be used as shrubs. Spruce has scaling or
flaking bark, and, in general, its needles are short enough for use in
most sizes of bonsai, with many dwarf varieties available.
Due to the branch formation in whorls and natural
tendancy of some spruce species towards pyramidal growth, the spruce can
be a difficult bonsai subject. It enjoys popularity, however, because it
makes a stately bonsai when properly styled, and material is readily
Needlelike leaves are persistent for several
seasons, but much shorter than those of pine; born singly and closely in
spirals; four-sided or diamond-shaped in cross section. Each leaf
appears narrow at the base. Flowers appear as small cones, male and
female on the same tree. Spruce have a pendent woody cone with thin,
smooth or ragged-edged scales.
Lighting: Full sun,
but needs shade from the midday sun in summer, or needle browning will
northern trees prefer cool temperatures, although small or young bonsai
may need frost protection. Many species are hardy to zone 3 or colder,
although there are some which grow well only as far north as zone
6.Picea glauca 'Conica' is capable of withstanding heat and drought
better than other spruce bonsai. In general, spruces like wind and need
prefer moisture, but not waterlogged soil. Reduce watering in winter,
but never allow the soil to dry out completely. Misting is appreciated
Feeding: Every two
weeks, spring-midautumn, using liquid bonsai food or half-strength
general purpose fertilizer. In hot areas, discontinue feeding during the
heat of summer. Apply a chelated iron supplement several times
Pruning and wiring:
Popular both as single specimen trees and when grown in forest plantings
- 'Little Gem' spruce is especially popular for Saikei. Jin and shari
look especially nice on spruce bonsai. When purchasing spruce for bonsai
purposes, be careful to avoid grafted trees as these will form unsightly
bulges at the base. Suitable for all styles except broom, and for all
sizes, with small sizes best reserved for dwarf varieties. New growth
should be pinched, not clipped, several times in spring, when shoots are
about 1 inch long, leaving 4-5 clusters of needles. Do major pruning in
early fall. Never remove all needles. Wire between late autumn and
winter. Picea glauca 'Conica'is a slow-growing specimen. To encourage
compact, dense growth on it, pinch out the apical buds as they emerge
and cut back long shoots. It does not set as well when wired as other
trees. It is often necessary to exaggerate the bend desired when wiring
to end up with proper branch placement.
need cold pre-treatment, and are generally sown in winter or early
spring. Seeds may be collected from cones between September and January,
late August-September for P. glauca. Remove seeds as soon as they appear
at the edge of the scales, but allow them to mature in the cones as long
as possible. Softwood cuttings may be taken in late autumn or early
spring, but rooting is tricky and may take up to two years.
general, epot every second year in early to mid-spring, before new
growth expands, or in early fall. Older specimens (+10 years) may be
repotted every 5 years. P. Abies may only need repotting every 3-4
years. Use fast-draining soil mix, and prune roots by 1/3 or less.
Spruce, in general, need to keep a decent-sized root ball, and may need
to be planted in a deep pot to achieve this. Protect from full sun for a
few weeks after repotting. P. jezoensis should be allowed to rest for 3
months after transplanting before wiring. Picea engelmannii is one of
the toughest spruces, and is forgiving of mistakes made due to
over-enthusiastic root/branch pruning.
Pests and diseases: Mites are the worst problem, and in hot weather they can
build to populations which require control. They can be a major problem
in summer after hot dry weather, especially near concrete, buildings,
and other urban surfaces which reflect heat. The small insects can't be
readily seen with the naked eye. The first noticeable symptoms are
yellowing at the base of the oldest needles on infested branches. Close
inspection with a magnifying glass will confirm the presence of the
Two gall-forming insects commonly attack Spruce.
Eastern Spruce gall adelgid forms pineapple like galls at the base of
twigs. Galls caused by Cooley's Spruce gall adelgid look like
miniature cones at the branch tips. The gall adelgids do not kill trees
unless the infestation is heavy. A few galls on a large tree are not
In northern climates, Spruce budworm larvae feed on
developing buds and young needles. The yellowish brown caterpillars are
difficult to see.
The Spruce needle miner makes a small hole in the
base of a needle then mines out the center. Dead needles are webbed
together and can be found on infested twigs. Hand pick these from the
tree to reduce future damage.
canker infects a branch then eventually kills it. The lower branches are
attacked first then progressively higher branches. The needles
turn brown to reddish brown and eventually drop off. White resin
patches are seen on infected branches. Prune off infected branches.
Water Spruces during dry weather.
Spruce may be attacked by needle casts. One causes
needles to turn yellow or brown and drop off. Another affects the lowest
needles first then moves up the tree. Infected needles are a mottled
Some species suitable for bonsai:
- Picea abies: Norway spruce - With its red brown
bark, conical shape, and shiny green needles, Norway spruce is
traditionally used as a Christmas tree. Its needles are 3/4 inch long,
and it grows to 90 feet in nature. It survives at high altitudes, up
to 6600 ft.
- Picea abies albertiana 'conica'.
- Picea abies 'Echiniformis': dwarf spruce - a
slow-growing form with tightly congested foliage.
- Picea abies 'Little Gem': dwarf spruce - an
excellent variety for use in Saikei due to its tiny needles and small,
- Picea abies 'Maxwellii': Norway spruce, dwarf
spruce - This is a natural dwarf. It has
coarse, spiny needles.
- Picea abies 'Mucronata': dwarf spruce.
- Picea abies 'Nidiformis': bird's nest spruce -
This dwarf has bright, fresh green buds and grows to 3 ft.
- Picea abies 'Pumila' - This variety has small,
dense foliage which makes it desirable for bonsai culture. It grows
very slowly - as little as 1 foot in a 25 year period.
- Picea abies 'Pumila Nigra' - small, deep green
foliage, with light green buds in spring. Takes well to pot culture in
hot, humid areas. Very similar to the hard-to-find P. glehnii.
- Picea abies 'Pygmaea': pygmy Norway
- Picea abies 'Verigata': white spruce.
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