Monkey puzzle trees are fun and unusual perennials that add an unexpected shape to the landscape. The branches grow in a parallel fashion with space in between. Native to Chile and Argentina, these plants have persisted on Earth for more than 200 million years.
The International Union for Conservation of Nature classified A. araucana as an endangered species in 2011 due to a decreasing population trend, citing both the decline of mature individuals and the decline of habitat. It’s one of about 20 species in its genus, and quite a few of the other species are dwindling as well.
They are relatively easy to care for, and their growth is slow but steady. The greatest difficulty in growing these plants is providing the right amount of water. They are used to the significant precipitation of the Andes mountains, but they’re also prone to rot in wet soil.
Far from their native land, monkey puzzle trees are now planted in landscapes in mild climates all over the world. If you live in the right zone, you can add one of these striking living fossils to the landscape.
Araucaria araucana Overview
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What Is It?
Monkey puzzle tree is an evergreen conifer known for its symmetrical branches that grow with lots of open space between them. In its native habitat of the Andes mountains in Chile and Argentina, it can live to be more than 1,000 years old, earning the nickname “living fossil.”
This species is the national tree of Chile. Though it’s not naturalized in the United States, it’s often grown in the South and the West Coast in USDA hardiness zones 7 through 10.
Characteristics
This perennial has a pyramidal growth habit. Its branches grow without touching each other and form a unique, geometric shape. Small, triangular leaves spiral densely along the branches. This species does not provide much shade, due to the branches’ sparse growth.
They add unusual texture and shape in the landscape all year long, though their large surface roots may interfere with the lawn, sidewalks, and foundations. Eventually at maturity, the branches widen to form a canopy, with no branches below, reaching 80 feet. This is highly unlikely in a cultivated, landscape plant.
These plants have either cylindrical (male) or spherical (female) cones that emerge in a shade of green before fading to yellow and then brown. The cones drop seeds in the fall. This can be a bit of a hassle to clean up, but they’re actually edible. These seeds are usually roasted similarly to pine nuts.
Native Area
This plant is native to the Andes mountains in both southern Chile and western Argentina. It grows on volcanic hills. This temperate location sees a lot of rain, experiences average humidity, and observes winter temperatures that go just below zero (~-18°C). This species will grow in similar, mild climates down to zone 7 as long as it gets enough water.
Planting
You can purchase small monkey puzzle trees and plant them in the landscape of your home. It’s possible to grow them from seeds, too, but the cold stratification and germination processes can take up to six months. Young plants can be kept in pots but will quickly outgrow them. When planting, consider that these trees can ultimately expand to 30 feet in width and will have sprawling roots.
Transplanting
To transplant a monkey puzzle tree, dig a hole that’s larger than the root ball. Place the plant in the hole and backfill with well-draining soil. Water the plant thoroughly and mulch around it to help the soil retain moisture while the sapling adjusts.
If you are moving a particularly large specimen, you may want to prune any branches you are willing to lose to reduce the overall size and weight of the tree.
Growing from Seed
Seeds must be cold-stratified before planting. Store them in the fridge in a moist sandy mix for two weeks to three months to mimic dormancy.
Then, plant the seeds with the pointy side facing down, leaving the top uncovered. Sow them in a well-draining, loamy mix. Keep the soil moist, but cover the seeds with a humidity dome or gently with plastic wrap. Place the seeds in a sunny window.
The seeds prefer a germination temp around 70°F (21°C) and may take months to germinate. Once they do, move the seedlings into small pots for a few years before transplanting them outdoors.
How to Grow
Monkey puzzle trees are fairly easy to grow and care for as long as you’re in the right zone and plant them in the right spot. These plants like lots of light and plenty of water, but other than that, they’re easy-going.
These perennials are not picky about soil. They handle most temperature swings as long as you stick between 0 and 100 degrees Fahrenheit (-18-38°C). They prefer typical outdoor humidity. Lastly, their fertilization and pruning needs are minimal and usually optional.
When small, this species can be grown indoors in containers. Since they prefer full sunlight, place them in the brightest spot in your home, ideally next to a south-facing window. Consider adding grow lights if the plant seems leggy. Plant in moist but well-draining ground, and do not let it stay dry for long.
Light
This species will grow in partial shade but will flourish in full sunlight. Plant them somewhere where they will get at least eight hours of direct sun for their best chance at success. In particularly hot regions, they may benefit from some midday shade.
Water
These trees prefer a lot of water. Their native region receives lots of rainfall, so these perennials are not used to dry soil. Young trees are especially vulnerable to suffering if their roots haven’t yet established.
Water these plants in times of drought, and mulch around them to keep the roots moist. Don’t forget to water recent purchases or transplants that are in pots.
That said, be careful not to overwater. This species is known to suffer from root rot, which is caused by overwatering, and Phytophthora root rot, which is fungal and spreads in wet soil.
Soil
Monkey puzzle trees are fairly laid back when it comes to soil. They can easily adapt to most areas as long as there is good drainage. You can plant them in shallow, rocky soil, clay, poor-quality dirt, and anything in between. They’re also indifferent to pH levels.
If you plant one of these living fossil in sandy or rocky soil, just note that you may have to water them more often.
Temperature and Humidity
Regarding temperature, this species prefers mild to warm conditions, preferring a range between 68 and 100°F (20-38°C). They will survive winters where the lowest temperature hovers around 0 degrees (-18°C).
Growers in zones 7 through 10 should have no trouble cultivating this species. In zone 7, mulch around the tree to help keep the roots warm in case winter gets chillier than usual.
In cooler zones, you could grow one of these trees in a pot and move it indoors in winter. However, in healthy conditions, they mature to 50-80 feet tall, so they won’t fit in a container for too long.
These trees prefer typical outdoor humidity levels around 50 percent. Lower humidity can cause the tips of the leaves to brown and become a little bit crispy. If growing as a houseplant, especially in winter when dry air is circulating from the heater, consider getting a humidifier to maintain comfortable levels.
Fertilizing
This species generally does not need supplemental fertilizer and can adapt to fairly nutrient-poor soils. However, if you believe that your plant’s growth has slowed down or otherwise suspect some sort of deficiency, you can supply some fertilizer.
Apply fertilizer at the beginning of the growing season. Amend with compost or sprinkle some slow-release fertilizer pellets. You could also use an all-purpose, water-soluble fertilizer, applying it once at the beginning of spring and again in early summer.
Avoid over-fertilizing. These trees aren’t used to a lot of fertilizer, and overdoing it can seriously damage their roots. If you’re not sure about whether your plant needs fertilizer or not, opt on the side of neglect.
Maintenance
These trees are truly low-maintenance as long as you have them in the right growing conditions. There is no real reason to prune them, especially since their natural growth habit has such a fun, geometric design.
If there are dying or dead branches that you’d rather not look at for aesthetic reasons, you can remove them. The best time to prune is in spring, giving the tree a chance to bounce right back.
You will notice that these plants slowly lose their bottom branches over time, which is a normal part of their growing process. This “self-pruning” makes maintenance that much easier.
Propagation
You can grow this species from seed, but the seeds need to be cold stratified first. This process takes two weeks to three months, and then it often takes multiple additional months for the seeds to germinate. For this reason, the best way to propagate these trees is by cloning their growth, through cuttings or air layering.
These methods aren’t difficult, but it will take a long time for new propagations to become sizable trees. During this time, you may enjoy keeping the young trees in pots while they’re still small enough to fit. This gives you the opportunity to move potted trees around the landscape for decor purposes or to easily bring them indoors as a striking houseplant.
Cuttings
Start by selecting a healthy, strong stem to be your cutting. Use a pair of clean pruners to sever the cutting at a 45-degree angle. Prepare a pot with loamy, well-draining potting mix. Optionally, dip the end of the cutting in rooting hormone and then bury it a few inches down.
Keep the soil moist but not wet. An easy way to do this is by placing a plastic bag over the cutting. Alternatively, lightly water or mist the surface just before it gets dry. Place the cutting in a sunny, warm window, and wait.
It may take a long time for the cutting to root and for new growth to show. There is no need to mess with the cutting while you’re waiting.
Air Layering
Air layering is a somewhat similar process to propagating through cuttings. Start by choosing a strong, healthy branch. Make a sharp cut in the branch just below a node. Cut through the center but do not fully sever the branch. It must stay connected to the host plant.
Optionally, apply rooting hormone to the cut. Cover the cut with a ball of moist sphagnum moss, and then cover the moss with plastic wrap to keep it wet. It may take a few months, but eventually, you should see roots growing into the sphagnum moss.
Once you see roots that are a few inches long, remove the plastic and the sphagnum. Now, you can fully sever the cutting from the host. Since it already has its own roots, you can plant it right away.
Popular Varieties
There are no other varieties or cultivars of monkey puzzle trees. One of about just 20 species in the Araucaria genus, these are truly unique plants. A. araucana is one of the hardiest members of its genus, which is possibly why they have become popular over time in Chile and beyond.
Araucaria is divided into four subsections. The only other tree in the same section as the monkey puzzle tree is the Paraná pine, which is critically endangered.
Common Problems
These trees do not struggle with many pests, nor do they have huge issues with diseases, as long as they’re not planted in poorly-draining soil.
However, these trees need fresh air and water to thrive and will not grow well in the presence of urban pollution. They aren’t great options for city sidewalks. They also have large, shallow root systems that can cause damage.
Some growers are put off by the seeds dropped by these trees, but others actively forage for them. Cleaning up these seeds is not difficult, and it only occurs once a year when they fall in autumn.
Pests
Monkey puzzle trees usually do not have a lot of pest problems, but they sometimes suffer from scale. You may see small bumps on the tree, which are actually the insects themselves. Scale can cause slower growth and yellowing leaves. On smaller trees, pop the scale off into a bowl of soapy water with a cotton swab soaked in 70% or less rubbing alcohol. Horticultural oils such as neem oil are effective at controlling scale.
If you’re growing indoors, you may also discover classic houseplant pests, like mealybugs, thrips, and spider mites. Use the alcohol method mentioned above for mealybugs. Neem oil may also be effective. Keep a close eye on your houseplants, and quarantine plants that appear to have pests.
Diseases
Common diseases that impact monkey puzzle trees include:
- Leaf spot, which looks like brown or black spots on the leaves. Remove damaged foliage. Then treat with fungicide or bactericide, depending on the pathogen source if necessary.
- Phytophthora root rot, which causes leaves to droop and curl as well as darker bark above the soil line. There is no cure, but you can prevent this rot by planting in well-draining soil.
- Root rot, which causes leaves to yellow and the soil around the tree to smell. Avoid root rot by planting in well-draining soil. Do not overwater.
- Sooty mold, which tends to look like a black, powdery “sooty” coating on leaves. Sometimes, a spray of water can remove the mold. Scale insects introduce sooty mold, so you can prevent it by controlling them.
Frequently Asked Questions
These trees have existed for hundreds of millions of years, with individual trees surviving for more than 1,000 years in the wild. They typically live for about 700 years. In cultivation, these living fossils probably won’t get that old, but it’s safe to say that they will live for a long time if cared for properly.
Deer and other mammals generally leave these plants alone, considering their sharp leaves.
Yes, you can dig up and replant these trees, but depending on how big they are, it may be a serious challenge. You can remove excess branches and even excess roots to make the process easier.
Part of the natural growth habit of these trees is for them to drop their lowest branches. The oldest, lowest branches will turn brown before they die off. This is no cause for alarm.
These trees tend to have a long, central tap root that’s actually about half its main height. Since this species can get very tall, they could have a seriously long tap root. This species also has a lot of shallower, sprawling roots that are much closer to the surface. These roots can tear up your landscape, so be selective when choosing where to plant.
