The Spruce tree is a magnificent evergreen tree. People plant it for ornamental purposes, for privacy, and as a Christmas tree. It belongs to the family of conifer trees (Pinaceae), genus Picea. The Spruce tree is the native of the cold regions of the Northern Hemisphere.
The Spruce wood pulp is a major raw material for the paper industry. And the Spruce timber is used in making different types of furniture. The wood has excellent resonating property also and widely used in musical instruments like the piano and violin.
How can you identify a Spruce tree?
The Spruce tree has lots of similarities with the other conifer trees like the pine and fir. All the three trees have ‘needles’ as their leaves, and they also have the cones. Incidentally, the general shape of the pine, fir, and Spruce is also similar. But there are specific identifying characteristics of the Spruce tree which differentiate it from the other conifers. You can visually identify the Spruce tree by just looking at the tree and its parts.
1. Needles: These are the leaves of the Spruce tree. In the case of a Spruce tree, individual needles come out of the stem. A woody peg called the pulvinus, connects needles to the branch. The needles are placed all around the stem, and it appears and feels like a bottle brush when you take it in your hand. The needle has a square cross-section, and you can easily roll it between your fingers. It is short and stiff. These are the general features of the needles, which are typical for all varieties of the Spruce tree. There are about 35 -40 different varieties of Spruce, and most of the Spruce variants have their own additional details about the needle. For example, in the case of;
Ø Colorado Spruce (Picea pungens): The needles of Colorado Spruce, is blue to silver-blue in color. The length of the needle is 3/4th to 1 ½ inch and has a very sharp and pointed tip.
Ø Black Spruce (Picea mariana): It has a very short, just ½ inch long, needle.
Ø Red Spruce (Picea rubens): The needles of this Spruce are yellow-green. When you crush the needle between your fingers, it smells like the rind of the orange fruit.
Ø White Spruce (Picea glauca): A very foul smell like that of a skunk comes out of the crushed needles of White Spruce. It is just one inch in length.
Ø Norway Spruce (Picea abies): It is dark green in color and just 1 inch in length.
2. Cones: The cones of the Spruce tree have very thin and soft scales. Because of this, the cone is very flexible.
The cones also differ a bit in the size and color of the species.
Ø Colorado Spruce (Picea pungens): In the case of Colorado Spruce, cones are dark brown in color and 2 – 4 inches long.
Ø Black Spruce (Picea mariana): The cones are a little roundish in shape and purple in color. It measures from ½ inch to 1 ½ inch and found on the higher branches of the tree.
Ø Red Spruce: The cone is reddish in color and small in size. Typically, about 1 ½ inch long.
Ø White Spruce: It has thin, delicate, and flexible cones. The color of the cone is light brown and 1 ¼ inch to 2 inches.
Ø Norway Spruce: The color of the cone is brown. It is relatively big 4 -7 inches.
3. Rough branches: As the needles fall off from the stem, it leaves the woody pulvinus on the stem. So when you touch the stem, you can feel the roughness of the woody pulvinus.
4. Upturned branches: The branches of the Spruce tree are upturned, that is, they point upwards. Pine tree also has its branches upturned. But the branches of the Spruce tree are far bushier than the pine tree.
What is the difference between Spruce and Pine trees?
Both Spruce and pine are conifers, and there are some general similarities between them. But there are perceptible differences between them in the needles, cones, branches, and the bark. These differences make it possible to differentiate the two.
The differences are in the;
- The needles of the Spruce tree are short and stiff. It has a maximum length of 1 ½ inch. The Spruce needle being square in cross-section, it is possible to roll the needle between the fingers. The stem grows individual needles.
- Pine tree needles grow in clusters. Unlike the Spruce tree needles, they are very long, growing up to 16 inches in length. The cross-section of the needle is flat, and the needles are so smooth and flexible that they make a swooshing sound in the air.
- The branches of the Spruce tree are upturned and very dense. It looks very bushy.
- Pine tree branches are also upturned, but needles are not so dense. These needles have spaces between the branches.
- The cones carry the seeds of the tree. The Spruce tree cones have very thin and flexible scales. The cone is very smooth to touch and bends easily.
- Whereas, the pine cone has rigid scales and is very rough. It cannot be bent.
- The Spruce tree bark is rough and scaly.
- When the pine tree is young, the bark is very smooth. But as the tree matures over time, its bark turns flaky.
The above differences are straightforward to notice and identify. Outwardly, the trees may look alike. But a closer look at the above points will help you differentiate between the trees.
How long does a Spruce tree take to grow?
It is a bit difficult to generalize the growth rate of the Spruce tree because we have around 40 different varieties of the Spruce trees. On average, the Spruce tree shows a growth of 6 to 12 inches in a year.
Nevertheless, it is worthwhile to mention the growth rates of some species, which does not fall in the average growth rate mentioned above.
Ø The Sitka Spruce (Picea sitchensis) grows to a maximum height of about 160 – 220 ft. During its growth cycle, it reaches a top growth rate of 60 inches/year till it attains maturity. It is hardy in the USDA zones 6 to 9. The Sitka Spruce has a canopy spread over 20 -40 feet and is a native of the western coast of the USA.
Ø Norway Spruce (Picea abies) is also a very tall variety of Spruce with a height of 100 -150 feet. It is generally found in northern Europe and is suitable in the USDA zones 3 through 8. The Norway Spruce registers the maximum growth rate of about 36 inches/year.
Ø The Colorado Spruce (Picea pungens) suitable to grow in the USDA zones 3 through 8, has a height of 30-65 feet. This variety of Spruce adds up to 24 inches in a year.
Ø Brewer’s weeping Spruce (Picea breweriana) has 12 feet spread and a height of about 50 feet. It is a native of California and endowed with hanging pendulous branches. It attains a growth rate of 24 inches/year.
Ø The Siberian Spruce (Picea omorika) is a native of Siberia. It is a narrow variety of Spruce of width 10 feet but grows to a height of 70 feet. It has a growth rate of 12 to 24 inches/year.
Ø Similarly, the Tiger tail Spruce (Picea torana) also has a growth rate of 12 to 24 inches, and it grows to full height to 85 feet with a 15 feet wide canopy.
The above examples show the growth rate climbing down from 60 inches/year to 12 inches/year. If you are planning to plant Spruce, you should be clear of your objective. For the sake of privacy and wind-breaking, a height of around 60 -80 feet should be enough. The tree will reach its height quickly. It is not only a matter of height, but the zone hardiness also needs due consideration.
In addition to the climatic conditions, the other factors which influence the growth of the Spruce tree are the 3 ‘S’; Space, Sunlight, and Soil.
Ø Space: It is essential to maintain a proper distance between the trees, taking into consideration the width of the canopy. The adequate gap between the trees will prevent damage to the branches, as they won’t rub together. Additionally, the roots will also not clash, and it will prevent the damage to the roots.
Ø Sunlight: The Spruce tree needs good sunlight. It is shade tolerant. But it grows well in full sunlight.
Ø Soil: The soil should not be dry, but at the same time, it should be well-drained. Waterlogging will make the roots and the Spruce tree sick. Acidic soil is the best, but it grows fine in neutral pH soil also.
Like any other tree, the Spruce tree also grows the best in its native environment. But if the above conditions are favorable, it can still maintain a fair growth rate.
Which variety of Spruce trees grow fastest?
The fastest-growing Spruce tree is Sitka Spruce (Picea sitchensis). This massive tree is a native of the Gulf of Alaska and named after the ‘Sitka’ community of Alaska.
It is found close to the sea, within 200 km of the coast. It grows from the sea level to a height of a maximum of 700 meters above sea level. Sitka plantations provide excellent timber.
The wood of the mature, full-grown trees is excellent for making boats, ships, packing boxes, and pallets. Whereas, the smaller trees provide the raw material making paper. The Sitka tree contains good quality cellulosic fibers needed to make the paper.
What is the lifespan of a Spruce tree?
In the native environment, the Spruce tree can live from 150 years to about 600 years, depending upon the species. However, the cultivated variety of Spruce trees have a shorter life of about 60 – 150 years.
According to the US department of agriculture forestry service, the Blue Spruce (Picea pungens) lives more than 600 years. The fastest-growing Spruce tree, Sitka Spruce (Picea sitchensis), has a grand life of around 500 to 700 years.
The Norway Spruce (Picea abies), which is the most popular Christmas tree in Great Britain and North America, has a lifespan of 150-200 years.
Though these are the most familiar figures on the lifespan of the Spruce tree, there are many Spruce trees around which are more than 800-900 years old.
How deep are Spruce tree roots?
Depending upon the species, the roots of the Spruce tree go down in the ground to a depth of 12 – 18 inches.
The spread of the roots is up to the width of the canopy. The roots at the far end of the network are thin feeder roots, which lookout for additional water and resources. The significant root system is limited to about half the width of the needle canopy spread. If you need to transplant the Spruce tree, it is enough to dig up to half the width of the canopy, and the depth can be around 1 ½ feet.
The roots of the Spruce tree are not really invasive. But it is always better to plant it away from the constructed property. It is to minimize the risk of any damage to the structure. It also ensures sufficient space for the roots to spread and grow.
The roots of the Spruce tree are sufficient to hold the big tree on its own. But competition from the undergrowth for water, and waterlogging can severely weaken the roots. And there is a strong possibility of the plant toppling over in the face of strong winds.
Hence when you plant the Spruce tree, ensure that the soil is well-drained, and there is no undergrowth, troubling the roots.
Do Spruce trees need sunlight?
Yes, the Spruce trees need the right amount of sunlight. Ideally, it needs about 6 hours of full daylight every day.
You should always try to plant the Spruce tree, where it can enjoy full sunlight. It will help it grow to optimum and be healthy. Adequate sunlight also prevents the Spruce tree from becoming sick and diseased.
However, the Spruce tree is shade tolerant as well. It grows well in partial shade too, but the growth will not be as robust and healthy.
Will a Spruce tree regrow needles?
The Spruce tree can regrow needles if it has lost them because of natural cause, and the parent branch is not diseased or damaged.
Though the Spruce tree is an evergreen tree, it loses some of the old needles from the inner part of the stem. Typically, a needle drops down after being there on the tree for about 2 -3 years. In such a case, new needles will appear on the branch.
Because of the cold and dryness in the winters, the Spruce tree is not able to get the required amount of water. Further, there is a transpirational loss of water from the needles. And because of this lack of moisture, the needles turn brown. It is also known as ‘leaf burn’ or ‘desiccation of leaves.’ If the branch holding the needle is healthy, new needles will grow in the place of old ones in due course of time.
However, if the branches are also damaged, then needles will not regrow. You can prevent the desiccation of the needles or at least reduce the desiccation by watering the Spruce tree from late summer throughout the fall. Covering the ground over the roots with mulch will keep the soil moist, and it can also minimize the water loss to a great extent.
Why do Spruce trees turn brown?
If the Spruce tree turns brown, it is an indication of some disease suffered by the tree. The following are some of the common reasons.
It is a fungal infection that afflicts the Spruce tree. In the initial stages, the needles of the lower limb turn brown and fall off. If the infection spreads further, the upper branches will also get infected gradually. Though it is not at all a fatal disease, it can harm the Spruce tree in a big way. It will affect the lifespan of the tree adversely. It is rather tricky to treat this disease, though you can try preventing it by spraying copper-based fungicides.
The only way the tree can fight this off is by improving its immunity. You can help by watering the tree well and supply nutrients through the fertilizers.
How do you keep a Spruce tree healthy?
You can keep the Spruce tree healthy by planting it well, watering and feeding it appropriately, and keep it away from diseases.
At the onset, decide a sunny place to plant your Spruce tree. The earmarked spot should have well-drained soil. A little acidic soil is better else, even neutral soil is fair. The Spruce tree grows better in a windy location.
While planting the tree, ensure that you do not place the root ball too deep in the soil. Maintain an appropriate distance from the adjoining trees if present in the surrounding. Cover the soil with an organic mulch of at least 3 to 4 inches in height. That will ensure the retention of moisture and supply of nutrients to the freshly planted Spruce tree. It also keeps the soil cool. The organic mulch consists of hay, straw, shredded bark, wood chips, and pine needles. The pine needles help maintain the acidity level of the soil.
In the late autumn/early spring, spread aged manure around the plant and gently work it in the soil. In case you see pests, or insects on the tree, spray water with force to wash them off the tree. If required, sprinkle a mixture of lime and Sulphur to destroy and drive away insects and pests.
Till the plant is young and freshly planted, try to keep the soil wet, but not waterlogged. In case some branches or leaves seem damaged or infested, remove them carefully from the tree to prevent spreading the infection.
In the case of the Spruce tree, just remember, if the soil is watered and well-drained and it receives appropriate sunlight and fertilizer on time, it will grow well. For nutrients, you can use a 10-10-10 fertilizer mixture in late autumn or early spring. Proper nutrition aids the tree to fight infections and pests.