Picea Mariana Bonsai Care Information

Picea Mariana Bonsai

Looking for a lovely bonsai specimen? Picea mariana, also known as black spruce, could be just what you’re looking for.

Although black spruce can be difficult to style as a bonsai, these plants are still popular. The plant grows slowly and requires little care on a daily basis. Furthermore, spruce looks great as a bonsai and is relatively easy to grow. As a result, despite being difficult to style, spruce bonsai is popular.

Don’t let the difficulty deter you from admiring Picea mariana bonsai. Many bonsai enthusiasts can keep this lovely bonsai in their collections. Although it is not the best choice for a beginner, if you have some bonsai experience, you can have success with black spruce.


Picea mariana, like most evergreens, thrives in full to the partial sun during the summer months. This spruce prefers full sun with some shade during the hottest part of the day. Picea mariana prefers more shade in the winter.

Although spruce is hardy to -10 degrees Fahrenheit, the roots should be protected during the winter. During this time, pots do not provide the same level of insulation that the ground would.

Because it is an evergreen, spruce does not go dormant in the winter. It is critical that the roots do not freeze and can continue to provide water to the rest of the bonsai tree. Picea mariana is wind resistant, so you won’t have to worry about protecting it from cold, strong winds during the winter.


Cool-temperature bonsai trees are black spruce trees. Black spruce trees grow naturally in areas with long, cold winters and short summers. Unlike some other bonsai, they do not need to be removed from the cold during the winter. During extreme temperature drops, you may want to move young Picea mariana into an unheated space that provides frost protection; however, in most climates, your bonsai should be fine in winter temperatures.

If you live in a hot climate, you might not be able to keep Picea mariana bonsai. Temperatures above 80 degrees Fahrenheit are not tolerated by black spruce for extended periods of time. Although providing shade during the midpoint of summer days can help, do not expect Picea mariana bonsai to survive if the temperature regularly exceeds 90 degrees Fahrenheit for weeks and weeks during the summer.

If you live in an area where it gets extremely hot, choose a different type of spruce bonsai. We’ll go over some of the other options in greater detail below.


Picea mariana bonsai are not picky when it comes to soil. They require soil that drains well but does not require any other special qualities. Even the pH level is unimportant to these plants.

How Often Do You Water Picea Mariana Bonsai Trees?

There is no set watering schedule for Picea mariana bonsai; however, water whenever the soil becomes dry. Depending on the environmental conditions, this will vary from plant to plant.

Although the soil does not need to be constantly soaked, black spruce does require frequent watering, especially during the summer. You won’t need to water as frequently in the winter.

The best way to tell if it’s time to water is to feel the soil with your finger. Insert your finger into the soil 2 inches away from the plant. It’s time to water the soil if it’s dry. If the soil is wet, you should wait a little longer before watering. It may appear simple, but this is the best way to determine when to water your black spruce bonsai.

When to Fertilize Picea Mariana Bonsai Plant

Because bonsai do not have access to the same range of nutrients as their native counterparts, fertilizing is essential. I normally recommend a balanced fertilizer (one with equal NPK levels) for most bonsai, but spruce can benefit greatly from a fertilizer with a higher nitrogen content, which promotes foliage growth.

I’d recommend fertilizing sparingly; you can always add more if necessary, but too much fertilizer can harm your plants, and there’s no easy way to get rid of it if you accidentally add too much.

For your Picea mariana bonsai, consider using a liquid bonsai plant food. From spring to autumn, fertilize every two weeks. During the hottest part of the summer, you may need to stop fertilizing for several weeks, but you can resume fertilizing once the temperatures have cooled down.

Despite the fact that spruce trees are evergreen, you do not need to fertilize them throughout the winter.

When to Repot Picea Mariana Bonsai

Bonsai must be repotted on a regular basis. You should expect to repot young Picea mariana every 2 to 4 years, depending on the rate of growth. More mature bonsai require less frequent repotting, so as your Picea mariana plant grows older, you will only need to repot it once every 5 years.

Spring is the best time to repot Picea mariana. When repotting, you can remove up to one-third of the roots. Depending on how much growth has occurred, you may or may not need to pot up (or move the plant to a larger pot). Spruce have large root balls, so plan on using a deep container to give them enough room.

Of course, whether or not you need to pot up, you should always repot with fresh soil. You should also keep your plant out of direct sunlight for a few weeks after repotting.

How Do You Bonsai Picea Mariana?

Because spruce bonsai are low-maintenance and slow-growing, you might think they’re the ideal beginner bonsai plant. Unfortunately, they are difficult to style, so Picea mariana is better suited to those with prior bonsai experience.

Having said that, spruce makes extremely attractive bonsai, so learning how to style them is worthwhile.

Picea Mariana Bonsai Styling

Almost any bonsai style will look good with black spruce. A broom is a sole exception. Straight-trunk, curved trunk, windswept, and multi-trunk are the best-looking styles.

Wiring is difficult because it can only be done in the fall and winter. Using wires in the spring and summer can cause branch death. Spruce branches are pliable and easily shaped with wires. However, if the wiring is removed before the spring, it will sometimes return to its original shape.

Nursery spruce styling can be particularly difficult. You’ll have better luck if you buy spruce plants that have been grown specifically to be displayed as bonsai. This will provide you with a stronger foundation upon which to build.

Pruning and Trimming

Despite the fact that black spruce is a slow-growing bonsai, it still requires pruning and trimming to maintain its bonsai shape. This procedure can also be challenging.

Picea mariana has whorled growth, which means that several branches on the tree grow at the same height. Except for one branch on the bottom half of the tree, you should remove all of the whorls. This means that extra branches should be pruned in the spring while the growth is still new and soft.

Any major pruning that is required should be done in the fall. You must, however, exercise caution and plan ahead of time. On old wood, spruce does not back-bud. If you don’t plan ahead, your bonsai may end up with bare branches.

Other Spruce That Bonsai Well

Black spruce is a popular bonsai tree. Because of its gray-green needles that grow to about 12 inches in length, dwarf black spruce (Picea mariana ‘Nana’) is especially sought after. However, not everyone lives in the right climate for this lovely specimen.

If the temperature regularly exceeds 90 degrees Fahrenheit during the summer, you will not have success with black spruce. But don’t worry, there are some other appealing spruce options.

Here are some other spruce species that might work better for you.

Picea abies, also known as Norway spruce, is probably the first tree that comes to mind when you think of a Christmas tree. This species is hardy to zone 7A, so it can grow in areas where other types of spruce cannot.

Picea abies ‘Pygmaea’: This is a dwarf Norway spruce. It’s another good option for those who live in hotter climates.

White spruce, Picea glauca conica, is hardy in zones 4-6. For spruce, it’s a popular bonsai option that can withstand heat and drought fairly well. Spider mite infestations are common in white spruce, so keep an eye out for them!

For those of us who prefer not to live in places with long, cold winters, there are several spruce options. However, if you don’t have any winter (i.e., you can wear flip-flops every day in December and January), you might not be able to keep a spruce bonsai alive. However, you most likely have a plethora of other plants that no one else can grow.

Picea Mariana Bonsai FAQ

Can spruce bonsai grow inside?

Indoor temperatures will almost certainly be too warm for spruce bonsai. Because black spruce requires long, cold winters, it’s unlikely that you’ll be able to provide that environment inside. However, if you have spruce that can withstand warmer temperatures, such as a Norway spruce, you can bring it inside for a couple of days during the Christmas season to decorate. But, for the most part, you should keep your spruce bonsai outside.

Is spruce good for bonsai?

Spruce can be difficult to style as a bonsai, but that doesn’t stop it from being a popular bonsai tree. Spruce grows slowly and does not require much care on a daily basis.

Does Picea back-bud?

Picea mariana rarely back-buds on old growth. Keep this in mind when trimming your bonsai and planning for new growth; otherwise, you may end up with a bonsai that appears more sparse than desired.

What pests are attracted to black spruce?

During the summer, spider mites can be a problem for black spruce bonsai, as they are for many spruce trees. Spider mites, which can quickly destroy a bonsai tree, can be difficult to detect at first and even more difficult to eradicate once they have reproduced a few times.

Prevent spider mites from appearing in the first place by spraying water on your bonsai’s foliage on a regular basis during hot weather. Once spider mites have attacked your bonsai, you have two natural options for dealing with them: the first is to use neem oil, and the second is to attract ladybugs, which are spider mite predators.

If none of these options work, you may have to resort to commercial chemical solutions. Spider mites can become resistant to common chemical solutions because they reproduce quickly. If you don’t get rid of all of the spider mites in two or three applications, you’ll need to try something else because the majority of the spider mites left will have developed resistance to that chemical after several reproductive cycles.

Do you have another question about how to care for your Picea mariana bonsai plant? Please leave a comment!

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