Thaumatophyllum xanadu
The xanadu philodendron (Thaumatophyllum xanadu) is a type of tree philodendron with an upright growth habit that sets it apart from the vining types.
Though it can grow tall with a substantial trunk, it will still behave as an epiphyte, clinging and climbing into any nearby trees, making it a secondary hemiepiphyte.
The name “xanadu” conjures visions of an idyllic paradise, somewhere luxurious to escape to, and you better believe when I first heard of this particular philodendron, images of a plant befitting utopia filled my mind.
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And since my idea of heaven doesn’t involve fussy plants that never look healthy despite my best efforts, xanadu has a permanent home in my houseplant collection.
In this guide, we’ll help you make your xanadu philodendron look as stately and dramatic as we all know they can.
Here’s what we’re going to talk about to make that happen:
Stately xanadu was originally called ‘Winterbourn.’
It was named for Veronica and Barry Winterbourn who patented the plant in 1988. As far as we know, it was first sold by an Australian Nursery, House of Plants, in 1983.
It was patented in the United States under the name Xanadu™, but the patent has since expired. You’ll also see it sold under the name ‘Aussie.’ Or it might be misspelled as “Zanadu.”
The history of the xanadu philodendron is wild. It’s like it appeared in commercial trade out of nowhere one day and everyone had a theory as to where it came from.
Quick Look
Common name(s): Xanadu philodendron
Plant type: Epiphytic aroid
Hardiness (USDA Zone): 9-11 (outdoors)
Native to: Brazil
Bloom time / season: Evergreen, flowers in spring
Exposure: Partial, dappled shade; bright, indirect light
Soil type: Loose, light, well draining
Soil pH: 5.5-6.5, slightly acidic
Time to maturity: 10 years
Mature size: 5 ft wide x 5 ft high (depending on cultivar)
Best uses: Hanging plant, houseplant, specimen
Some botanists believed it was a cultivar, sport, or hybrid of the tree philodendron, Thaumatophyllum bipinnatifidum (syn. Philodendron bipinnatifidum).
Others say it’s a recently discovered species from Australia.
The latter are wrong, since it’s not a native species from Australia. We know that there aren’t any indigenous Philodendron or Thaumatophyllum species there.
There are also gardeners who have been growing xanadu philodendrons from seed from plants collected from the wild in Brazil.
Like other members of the Thaumatophyllum genus, it most likely originated in South America.
In 2018, the Philodendron subgenus Meconostigma was reclassified as its own genus, Thaumatophyllum. This plant was assigned its own species: xanadu.
Tree philodendrons (T. bipinnatifidum) and xanadu look extremely similar. Only experts and serious hobbyists can tell the difference.
For example, the petioles of xanadu have a cupped, c-shape. On bipinnatifidum, they lack the cup.
Large, deeply-lobed glossy green leaves emerge from a wide central stalk which can grow up to four feet tall.
At maturity, the xanadu philodendrons will generally reach about five feet wide in cultivation. Wild specimens can reach almost double these dimensions.
When grown as a houseplant it’ll generally stay a lot smaller unless you repot regularly into larger containers and provide lots of bright sunlight.
In USDA Hardiness Zones 9 to 11 you can grow it outdoors and in spring it’ll bloom with a white spadix and spathe, followed by seeds in the summer. Indoors, the plant is unlikely to flower.
Xanadu makes a versatile houseplant either in a small decorative pot to keep it petite or gracing a large entranceway in a sturdy urn.
You can even grow it in a hanging container, where it looks super cool, though don’t expect it to weep.
Fun fact: Xanadu is a color reference for an off-gray color on the RGB scale. It has a color coordinate of #738678, and it was named for this plant.
There’s another tree philodendron known as ‘Xanadu-II’ which has larger and more deeply lobed leaves, but it has never gained the popularity of its parent.
How to Grow
Keeping xanadu happy is quite straightforward, provided you give it the conditions the plant requires.
Let’s start with growing medium.
Growing Medium
Aroids like xanadu philodendron need a chunky, loose potting medium with water retentive properties.
If you’re growing indoors in a pot, I’d recommend you purchase an aroid mix formulated for these types of plants.
Molly’s Aroid Mix is a good choice. It’s made up of bark, coco coir, worm castings for nutrients, biochar, and clay pebbles.
Molly’s Aroid Mix
You can find five-quart bags available from Very Plants via Amazon.
Or if you prefer to make your own, combine four parts orchid bark, two parts perlite, one part coconut coir, and one part worm castings.
Outdoors, amend your soil with plenty of coconut coir and bark, so that it is loose and airy.
You can also grow xanadu attached to a tree or other support. This is more difficult to do indoors because of the amount of space it requires.
But if you want to go this route, attach the roots using twine or glue – or both. Then, affix sphagnum moss over the roots.
You’ll need to keep the moss consistently moist at all times.
Light
Grow xanadu in bright, indirect light or morning sunlight.
Direct sunlight isn’t necessarily a bad thing, so long as it isn’t for more than a few hours in the morning or some dappled light throughout the day.
Providing plenty of light will help the xanadu philodendron grow large and bushy.
Outdoors, a part-shade location works best. If you’re growing in a sunny spot, make sure you provide some protection during very hot periods.
Water
Keep the soil evenly moist at all times. It should consistently feel like a well-wrung-out sponge and should never be allowed to dry out.
You should reduce the amount of water during the winter and allow the surface of the soil to dry out between watering.
It’s hard to say how often you’ll need to water, since how quickly the soil dries out will vary with environmental conditions.
Either use your finger or a moisture meter to check the soil every few days.
Temperature and Humidity
Xanadu likes it nice and warm. In their natural environment, they tend to thrive when the temperatures are in the low 80s.
But they’ll be perfectly fine in temperatures that range from 65 to 90°F.
You should avoid exposing your xanadu philodendron to anything below 60°F, though temperatures in the 50s for short periods are unlikely to do severe damage.
It might kill off the foliage but the roots will likely survive so long as the temperatures return to normal fairly quickly.
Xanadu grows in tropical rainforests so the plants are used to lots and lots of humidity. But they aren’t too fussy about the lower humidity found in most homes.
If you can keep the humidity to about 50 percent, that’s perfect. If you need to raise humidity, you can always keep your plant in the kitchen or bathroom, or use a small humidifier.
Fertilizing
For vigorous growth, feed your plant once a week or every other week using a mild, balanced, or all-purpose food.
If you’re looking for ideas, Arber makes a nice all-purpose option made out of chicken manure, biochar, and organic compost. It’s the product I use for all my aroids.
Arber All Purpose Fertilizer
You can pick up three-pound bags at Arbico Organics.
Reduce feeding to once a month during the winter months.
Where to Buy
You can find xanadu at lots of different retailers because it’s such a popular plant. You’re not going to have to hunt too hard to find it.
Xanadu Philodendron
If you’d like to start with something small, snag a live plant in a one-quart container from Nature Hills Nursery.
If you’d like something a bit older and larger, you can find a specimen in a 10-inch pot from the American Plant Exchange via Amazon.
Maintenance
Xanadu is a “self-heading” type, which is a term that philo lovers use to describe types with stiff, rigid stems that form a sort of trunk allowing the plant to grow upright rather than as a climbing or trailing variety like heartleaf or ‘Brasil.’
Left to their own devices, eventually they might become so large that they can’t support themselves.
This is the point when, in the wild, they would attach themselves to a tree to continue their lifecycle.
The lower leaves will shed naturally, leaving a bare stem.
Pruning
You don’t need to prune these plants unless any of the leaves die, become diseased or discolored, or there is a broken or deformed leaf you want to ditch.
To do this, sanitize a pair of pruners in isopropyl alcohol, a 10 percent bleach solution, or hot soapy water and cut the leaf off at the base close to the stem.
You can learn all the details about pruning philodendrons here.
Repotting
As the plant grows, you’ll need to repot it into a larger container. You’ll need to remove the original plant and brush away the soil before placing it in a new, larger container.
Choose a pot just one size up from the existing one. Remove the plant from its container, and gently loosen up the roots and brush away the excess soil.
Set the plant in the new container, and gently fill in around the roots with potting medium.
Water, add more medium if it settles, and you’re good to go.
Our guide to repotting tree philodendrons has more details.
Propagation
You can grow xanadu from seeds if you can gain access to them, but that’s a serious challenge.
Instead, we’ll focus on the more commonly available options of taking stem cuttings, air layering, offsets, and transplanting a purchased plant.
You can also separate offsets, but these don’t form and become viable for planting until the plant has developed a trunk.
From Stem Cuttings
To take a stem cutting, look for a healthy stem that is at least the diameter of your thumb and has several leaves. It should ideally have some aerial roots developing.
Grab a pair of sterilized pruners and fill a four- to six-inch container with aroid potting mix.
Cut a four- to six-inch length about an inch below a leaf or root node at a slight angle.
Remove all but one leaf and dip the cut end in rooting hormone. Make a hole in the potting mix and insert the cutting an inch or two deep, enough that it can remain upright.
Firm the soil up around it. Moisten the medium.
Move the container to a spot with bright, indirect light. Keep the soil moist at all times while it roots.
It will take a month or two, but eventually, the plant will start to grow new leaves and stems. That’s when you know your cutting has taken and roots are developing.
By Air Layering
Aroids develop aerial roots and we can harness these for propagation. Look for a branch with an aerial root node.
Place a stick next to the branch you’re going to propagate. This will support the branch as it grows.
Take some sphagnum moss and moisten it. Wrap this around the node and cover it in clear plastic. Secure this moss and plastic to the support stick using tape or twine.
All you need to do now is keep the moss moist and wait for roots to develop. When you see a mass of roots forming in the moss, it’s ready to go.
Remove the plastic cover and moss, and cut the plant just below the roots.
Plant this in a new container or spot outside. The container should only be slightly larger than the root mass.
From Offsets
When the plant is mature and has developed a trunk, it will start to form offsets.
These look different from newly-developing leaves, because they will have their own central stem and several small leaves.
Offsets develop from the underground portion of the meristem. All you need to do is dig down with your fingers along the stem until you find the point where the offset joins the main stem.
Take a knife or pruners and gently cut this away, taking any roots attached if you can.
Plant the offset in its own small pot.
Managing Pests and Disease
Xanadu is one tough cookie. In a group of friends, this would be the one that never cries, walks it off when they break a bone, and can handle pretty much any challenge.
Mealybugs, scale, and spider mites will all feed on xanadu philodendrons, but they usually won’t cause much damage. Yellowing foliage and some reduced growth are the main symptoms.
Mealybugs and scale can resemble the symptoms of a disease, since these pests are fairly flat and they don’t move once they hunker in and start feeding.
You might see fine webbing on the plant if spider mites are around, but the arachnids themselves are so tiny that they’re not really visible.
Otherwise, root rot is your biggest concern. Root rot is a common problem for houseplant growers, in general. Learn about how to prevent, identify, and control root rot here.
Welcome to Paradise
If your own personal paradise involves lots of pretty tropical plants, you should absolutely include stately, elegant, eye-catching xanadu.
Are you growing xanadu philodendrons? Let us know what you love about this plant in the comments section below.
If you have a hankering to learn more about philodendrons, we have a few other guides to keep you busy. Check these out:
