Picea or spruce are amongst the type of trees that contains a lot of subspecies and cultivars. It is very popular and the sale of this tree is a very lucrative market. The famous Christmas tree is usually a spruce or a fir. In general, they are tall trees with a conical or pyramidal growth habit. The bark is flaky and the needles are of a deep green color. The needles are smalls enough, smaller then pines, which makes it a good bonsai candidate, plus many dwarf varieties exists. However, the growth habit can be difficult to properly style as a bonsai tree. It is a widely available tree and cheap material can be found in many nurseries.
Some subspecies are more popular as bonsai because of their special and unique characteristics.
Picea Abies
(Norway Spruce)
This species is very cold hardy and can be a good candidate for bonsai adept located in colder climates area of the world. It possesses medium size needles at about ¾ of an inch. The color of the needles is more of a light green then other species. The bark is more reddish and brown then other spruce tree which makes it a good tree to have in your bonsai collection. This subspecies can be found in many cultivars. Some are more suitable as bonsai tree then others.
Picea Glehnii
(Sakhalin Spruce)
This is another popular subspecies as bonsai tree especially in Japan. It as various common name such as: common Ezo spruce, Edo spruce and silver fir. The bark is once against of a reddish to brown color, but the needles are special as they are more blue then green. This subspecie can also be found in a yatsubusa form which makes it very similar to the Picea Abis “little gem”. This can be more difficult to find, both in regular and yatsubusa form, then other subspecies of the spruce.
Picea Jezoensis
( Yezo Spruce)
Less hardy then other subspecies, this spruce is not less beautiful. It is very popular in Japan and can be found under different names such as : jezo spruce, Hondo spruce, Yeddo spruce It prefers a semi-shade condition. It possess small needles which makes it a great bonsai subject. The needles are dark green in color with a white underside. The young shoots are brownish in color.
Picea Orientalis
(Oriental Spruce)
This is a very bonsai candidate because of the very small needles. They are usually a quarter of an inch long, and a long needles for this subspecies is not more then a third of an inch. It is also a showoff tree species because of its deep purple cones. The bark also sets this subspecies apart because it is of a light grey color. The needles are the usual deep green color. Not very hardy, this specie prefer hot and humid conditions of growth.
Picea Koyamai
(Koyama Spruce)
The needles of this Japan native spruce tree are rarely longer then half an inch and are usually shorter. It is the rarest spruce subspecies to be found in Japan. It grows in the Japanese mountains in a pack of 10 to 20 trees. It is reported that only 250 or so of these trees can be considered as matured tree in Japan. It is also rare outside of Japan. The needles are light green in color. It prefers a wet peaty soil.
Spruce Bonsai Care
Light
The spruce tree usually prefers full sun conditions to the exception of a few subspecies. In the biggest heat of summer, the spruce can be susceptible to needles browning and this problem is usually addressed by providing shade for a few hours.
Watering
Since spruce tree prefers a more wet then dry soil, watering properly is essential. You should never let the soil dry and even when over wintering a spruce bonsai, you should verify that the soil is humid.
Feeding and fertilizer
Spruce bonsai will need some help in the growing season. Natural fertilizers such as fish emulsion or home made recipe are a good choice. If you can’t get these locally, you could use a chemical
tree fertilizer. A low content fertilizer can be used every week, or a general 20-20-20 fertilizer can be used every other week during the growing season. Some prefer to use a 20-20-20 fertilizer at half dose every week. Fertilizing should occur at the beginning of spring, right after last frost, and should be stop when you notice a reduction in growth rate of your spruce bonsai. At the peak of summer, fertilizing is optional for a few weeks. Chelated iron is needed to keep the tree healthy and should be plied a few times a year.
Spruce Bonsai techniques
Spruce is often seen as saikei bonsai and they make a beautiful arrangement. It is suitable for every bonsai style except broom. New shoots should be pinch in early spring and major pruning should be done in fall. It is important to never remove all needles to prevent lack of budding back. Wires should be applied in winter.
Spruce bonsai Diseases and Pests
Mites are the biggest problem of spruce bonsai. In hot summer days, it could become a problem that need to be controlled with chemicals.
A weaker tree can be susceptible to an attack by borers.
Gall and bagworms insects are also some common insects that prey on spruce tree.
Cytospora canker is the most common disease found on spruce tree. It attacks a tree branch by branch, usually starting with the lower ones. After it is done with a branch, it is usually already dead.
Spruce bonsai Propagation
The spruce tree is best propagated by seeds. The seeds will need cold pre-treatment before germinating.
It is possible to propagate a spruce tree with cuttings. Only softwood cuttings will successfully root. However, rooting a spruce cutting can be hard and some have reported that a spruce cutting can take up to two years to successfully root.
