Bonsai trees can take a multitude of forms depending on what species is grown as a bonsai.
Some people prefer to grow succulent plants as indoor bonsai trees, or flowering plants for color, but one of the most popular trees to cultivate as a bonsai is the pine tree.
It’s one of the most well-loved and versatile plants to grow as a bonsai, as there are so many species of pine to choose from, and all can be wired into different bonsai growing styles.
Here’s everything you need to know about growing pine bonsai trees.
At a Glance: What You Should Know About Pine Bonsai Trees
Pine trees are conifers which make up the Pinus plant genus. There’s around 126 species which are currently accepted within the genus.
Some pine tree species are better suited for growing as bonsai trees than others.
While they are among some of the most beautiful bonsai trees you can grow, they aren’t generally recommended for beginners (see also Bonsai Care For Beginners), as they can be demanding plants, difficult to diagnose when there’s a problem.
However, they are very long-lived, rewarding plants when given the right care. A pine bonsai tree can live for a hundred years or longer.
Depending on the style and species selected, a pine bonsai can reach anywhere between 150 and 200cm tall, and between 30 and 80cm wide.
Can You Grow Pine Bonsai Trees Indoors?
The mistake that many people make when trying to grow a pine tree as a bonsai is that they attempt to grow the tree indoors. Pine trees, even when cultivated as bonsai, need to be outside in order to survive.
The atmosphere in our homes is too dry and too warm for pines, and without the outside weather and temperatures, the plant cannot tell when it should go dormant. Without this period of rest, the pine tree will die.
Should You Grow Pine Bonsai Trees from Propagation or Grow Them From Seed?
You can grow pine trees for bonsai cultivation from seed or by propagation. Pine trees are one of the easier types to grow from seed, but you’ll notice quicker results by growing them from cuttings.
You can air-layer pine trees, but this is one of the most difficult types of tree to propagate by air-layering, so you have been warned!
Types of Pine Trees You Can Grow as Bonsai Trees
It can be difficult to know exactly where you should start when it comes to growing pine trees as bonsai. Here are some of the most popular types of pine tree cultivated as bonsai.
Pinus mugo ‘Dwarf Mountain Pine’
One of the hardiest pines you can grow as a bonsai tree, this characteristic is very helpful if you live somewhere with fierce winters, as you cannot keep pine bonsai trees indoors and expect them to thrive.
It also helps that the dwarf mountain pine can withstand fierce sunlight, much better than other types of bonsai.
This is one of the easier types of pine to grow as a bonsai, as it is a more compact variety, making the care just a little bit easier.
There are many cultivars to choose from, so there’s bound to be a variety that fits into place with how you want the pine bonsai to look.
For the most part, the dwarf mountain pine grows in rocky soil or even bedrock, which makes it a very suitable species to grow as a bonsai, as the roots are tough.
Most cultivars feature small green needles, arranged in pairs along the dense branches, setting a good contrast against the deep brown trunk.
Pinus parviflora ‘Japanese White Pine’
One of the advantages of growing a Japanese white pine as a bonsai is that the branches stay flexible for a prolonged period as they age, making this species an easy one to wire.
You’ll also see it labeled as the five needle pine. It’s very easy to care for, as the plant is robust and not easily troubled by pests.
It also helps that the growth rate of a Japanese white pine is very slow, so you won’t have to tend to them very often.
You can easily recognize this bonsai by its long, blue-green needles, growing in groups of 5, and its brown cones produced in autumn.
When the plant is young, it has more of a conical shape, and as it matures, the growth spreads outward.
Pinus sylvestris ‘Scots Pine’
A favorite of many bonsai growers, the ‘Scots Pine’ is easily recognizable with its orangey-red trunk, small green-blue leaves, darkening in winter.
The reddish hue of the bark becomes more pronounced further up the trunk of the tree.
Pinus thunbergii ‘Japanese Black Pine’
The Japanese black pine is one of the most difficult species to grow as a bonsai tree (see our dedicated Japanese Black Pine Bonsai Guide here), but it’s also one of the most popular species to try.
It features long deep green needles which form in pairs, and a near-black trunk. It has a reputation of being difficult to style, and its slow-growth rate can make things a little more tricky.
How to Make Sure Your Pine Bonsai Thrives
It’s worth knowing that pine trees can have one or two flushes of growth per year, and this is dictated by the species.
This doesn’t affect their care too much, but for best results, you will need to alter it slightly depending on the tree species you are growing.
Sunlight and Position
Pine bonsai trees need plenty of light in order to thrive. This is one of the biggest requirements in order to ensure that your bonsai lives a healthy and happy life, so somewhere with lower light levels will not do.
If a pine bonsai tree doesn’t get enough light, the needles will elongate, and the bonsai may drop its branches.
They also require a sheltered position, away from winds. While they can weather freezing temperatures quite well, one thing that they are particularly vulnerable to is freezing wind.
As for the soil, use a specially-formulated bonsai mix to make sure it can drain well.
When to Water a Pine Bonsai
Getting the right amount of water for a pine bonsai tree can be tricky. You’ll need to be free enough to check the soil at least once a day.
Only water a pine bonsai tree when the soil is nearly completely dried out, and water it generously.
Keep in mind that pine bonsai trees hate water pooling at the roots for too long, and there’s an equal dislike for completely dry soil, too.
Should You Feed a Pine Bonsai?
Pine bonsai trees don’t require a lot of fertilizer. It’s best to give them less than other bonsai trees, as a lot of fertilizer can mean the needles grow too long, which makes maintaining the shape more difficult than it needs to be.
Once the growth starts in early spring, feed the pine, and then hold off until the end of spring to feed it again. From summer until the start of autumn, use a fertilizer every two weeks.
Don’t feed the plant at all during winter months.
Use a balanced bonsai fertilizer (see our Bonsai Fertilizer Guide), avoiding those which contain high levels of nitrogen. Always use fertilizer just before you water the plant. Don’t water it and leave it with dry soil, otherwise this will cause root burn.
How to Repot a Pine Bonsai
Repotting only needs to be done every 2 to 5 years. Always repot a pine bonsai in spring once signs of new growth appear.
When you remove the old soil from the roots, leave about half of the roots untouched. This will help retain the naturally occurring fungus mycorrhizal in the roots, which will help keep your bonsai tree alive.
Cut any roots which have gotten too long, but don’t prune more than a third of the root system.
When putting the new soil into the container, first add a layer of grit to help improve drainage.
If you’re growing a mountain pine as a bonsai, it will respond best if you repot it during summer.
Problems to Look Out For
One of the biggest ways to keep your pine bonsai tree healthy is to make sure you place it in an area where it will get a good amount of sun, and avoiding over watering the plant.
This will prevent a myriad of pests and disease, as a healthy pine is very robust.
That’s not to say that your pine bonsai will always be trouble-free, however. Keep an eye out for aphids, caterpillars, scale, and spider mites.
As you’ll be keeping this bonsai tree outside, you’ll need to check regularly for pests, as it’s more likely to get pests than bonsai trees you keep inside.
How and When to Prune a Pine Tree Bonsai
You should wait until autumn to heavily prune your pine tree bonsai. The reason for this is that the tree will lose less sap, keeping it healthier.
Don’t be too hard when cutting back your pine. Do it gradually, otherwise you risk killing the plant.
If you don’t plan on taking a lot of growth off your pine tree, you can do this during the spring or summer.
Remove old needles, and avoid the pine from getting top-heavy, which, if left unchecked, will compromise the stability of the whole tree.