Wicked Witch of the West (Philodendron 'Xanadu')

Part Two of the Wizard of Oz series brings us to Philodendron 'Xanadu.' I feel a little bad about this; my only other Philodendron profile to date ('Autumn') was fairly negative, and this one's going to be as well. It's not that I don't like the genus. Quite the contrary, I think they're swell. They, however, are not thrilled with me, apparently. And unlike 'Autumn,' 'Xanadu' doesn't like me at home or at work: most plants only misbehave for me in one place or the other.

But so the question I'm sure you're dying to have answered is, what on earth could the connection be between this plant and this character?


That's right. Philodendron 'Xanadu' melts if you throw water on it. And sometimes when you don't, too.

My first encounter with this was last December. We got in a box of 'Xanadus' from our tropical supplier, and within the box, each plant was in an individual plastic sleeve. (Some growers do this: it keeps leaves from getting entangled during transit, and makes it easier to pack boxes.) When we took the sleeves off, a number of the leaves were basically liquefied, stuck to the plastic, or to one another. And there was an odor as well. Oh, holy Hostas, was there an odor. The best description I can manage is, imagine celery that's in hell and is really unhappy about it. It didn't have the ammonia edge of some rotting plants,¹ which is good, I guess, but it was still profoundly unfriendly.


We did the best we could, stripped off the leaves that had fallen apart, and called it a case of cold damage, that being the only theory we really had to go on. I mean, it was December, so it was cold, and the trip up from Florida always takes at least three days. But the disintegration kept on going for quite a while after that: perfectly intact leaves would develop water-soaked patches at the edges, which would enlarge, and eventually those leaves, too, would melt. A faint angry-celery odor lingered around the plants even after they stopped shedding leaves, in the way that a paroled arsonist might linger in the paint-thinner section of Lowe's.

And amazingly, they all sold, eventually (they're pretty plants, undeniably, when they're healthy and happy), so we ordered more this summer. And it all happened all over again. Vile odors, liquefying leaves, everything exactly the same except the theory. 'Cause obviously cold damage was not the problem this time.

In the end, I concluded that it was a bacterial infection (very likely the same one that caused the Dracaena marginata referenced in footnote 1 to rot), and that they had probably shipped with the infection already fairly widespread, and the only thing to do would be to just not get any more 'Xanadus' until we could either get them from somebody else or figure out a quick and easy cure.

And then I found a specimen that I, personally, couldn't pass up.

It was a big plant, in like a two-gallon pot, for sale at Peck's, yet another garden center in Cedar Rapids, and they (mysteriously, inexplicably) only wanted $5 for it. There were a few leaves that looked damaged, in a burnt rather than melty way, and there was a bit of the angry-celery odor, but by this point I'd kind of forgotten how long and drawn out it had all been during the winter, and the summer problems had basically ended and turned into a different problem (don't worry, I'll get there), so I thought well, what the hell, $5 for a $30 plant -- I'd be a fool not to, right?

And it looked pretty good when it first got home (not that it's the best picture, but at least you can gauge overall size and fullness):


And it's been going downhill pretty steadily ever since. The rotting leaves stopped, but it's still throwing leaves. So now it looks like this:


By the time this gets posted, I will have donated the plant to work, where it will either recover, be priced, and get sold, or continue to decline until it's thrown out. I don't want it anymore, whatever the outcome.

The likely cause of the rot, by the way, is Erwinia, a bacterium which causes rot in a number of plants besides just Philodendron and Dracaena: we've had some Dieffenbachias with it too, and it works the same way: liquefying, noxious-smelling leaves, though somehow each genus produces its own individual eau de yuck, and Dieffenbachia's has a weird sort of burnt note to it that the others don't.² Erwinia bacteria can be spread from plant to plant merely by having them touching, but it also spread if water splashes off of one plant and lands on another (I wasn't kidding about 'Xanadus' melting when you throw water on them.), or via infected hands or tools. The good news is that most of the time, removing the affected tissue, giving the plant better air circulation, allowing the plants to dry out, and separating plants further from one another will take care of the problem.³

The bad news: some plants seem to be able to hang on to their Erwinia potential even when they're properly spaced, watered, and groomed, and as best as I can tell, P. 'Xanadu' is one of those. So that kind of sucks. In fact, it may have caused the continued downhill slide of my plant: I didn't put my 'Xanadu' with the other plants, because I didn't want them to catch the infection,⁴ which means it was in a very un-choice spot: dark, possibly cold (it wasn't exactly in the path of an air conditioning / heat vent, but it was close enough that I had questions about it), and -- although I don't know that this is necessarily an issue -- there may also be a high ethylene concentration there too.⁵



LIGHT: Philodendrons will usually tolerate fairly low light for quite a while, and I'm told by our supplier that 'Xanadu' is usually a pretty good long-term low-light plant as long as you are very sparing with the water. Bright indirect light or filtered sun are probably still best, if available. I wouldn't do full sun indoors if you can help it.
WATERING: Less is definitely more, here. Our supplier said that the Erwinia problem could have been because the plants were shipped wet. (Not that anybody remembers whether they were: it's been almost a year.) Any kind of standing in water, or even heavy soil that dries slowly, is capable of causing problems. She characterized 'Xanadu' as being one of those plants that does best if neglected, and this is, like I said above, especially the case if it's in low light. That said, you are going to have to water it sometime, and although I know you expect me to know, I'm afraid I can't really tell you how to figure out when those times should be, since I've never managed to figure it out on my own plant. Sorry to disappoint. Even in the hot, bright, greenhouse, though, these seem to get by best on very little water.⁶
TEMPERATURE: Normal Philodendron temperatures. Keep out of drafts, don't ever let the temperature go below 50ºF (10ºC), and try to maintain a more or less constant environment between 65 and 85ºF (18-29ºC). The growers' guide says cold damage often shows up on 'Xanadu' as a reddish discoloration, though I've never seen this on the work plants. There are people on davesgarden.com who claim that it will take cold temperatures (to 20ºF / -7ºC !?) and remain alive (though foliage will die back), and will even accept being gradually cooled down (over a period of several months) to 37ºF (3ºC) without dying back.⁷ I wouldn't take these kinds of risks personally, but at least you know that a chill isn't necessarily the end of the world. They actually seem not to mind extreme heat, either: we've had some in very hot, dry spots before and they didn't act like that was a problem. It might actually be helpful, if they're not drying out fast enough.
HUMIDITY: Our supplier says that this is not usually a big concern, and like I said, there have been plants in hot dry spots in the greenhouse before, without noticeable impact.


PESTS: The usual suspects: spider mites, scale, mealybugs, though none of those seem to be huge issues. (Of course, it's hard to get spider mites when your leaves are only occasionally in solid form.) Erwinia is far and away the most serious pest/disease issue with 'Xanadu,' in my experience, and the way our supplier talked, it seems like that's the major problem on the wholesale side too.
GROOMING: I would think this one would be pretty obvious from the text.
FEEDING: Philodendrons as a genus are, according to the growers' guide, relatively heavy feeders, and that is more or less confirmed by my own experience. So it should be okay to feed with every watering, possibly not at full strength.
PROPAGATION: 'Xanadu' is a patented variety, so propagation for sale is prohibited by law. Propagation for personal enjoyment is not prohibited so much as just not really possible: some Philodendron species (e.g. P. selloum) will form offsets at the plant's base, given a healthy plant, favorable conditions, and enough time, but it's not fast, and not especially likely indoors.⁸ I would bet that 'Xanadu' is instead propagated mainly by tissue culture, like 'Autumn,' 'Prince of Orange,' and 'Moonlight,' (also patented hybrid Philodendrons) so the only form of propagation available to most of us is division.

If you find yourself stuck with one of these plants, I suspect there are only two routes to success: one, you can observe it very very closely and see if it drops leaves after you water (in which case you're watering too much), and write things down (dates of watering, what it did afterward) until you figure out what works and what doesn't, or, two, try to ignore it completely and hope to luck into an arrangement that works.

Personally? I give up.


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Photo credits: Wicked Witch photo via shawnnacox.com; "Surrender Dorothy" is from www.wizardstower.co.uk; all others are my own.

¹ The all-time winner, which will hopefully never be equalled or surpassed, is a Dracaena marginata cane I smelled after it had gone rotten. It was described with words and phrases like sharp, ammoniacal, dear Jesus what is that, and I'd rather poke my eye with a sharp stick than smell that again.
² Yeah, that's right: put me in a room with a bunch of liquefied, rotting tropical vegetation, and I can tell you what genus it's from. That, and the ability to visually identify 3-, 4-, 6-, and 8-inch pots, both standard and azalea proportions, from a distance of twenty feet, are the main superhero skills I've picked up from this job. The pot-size thing, actually, has gotten to the point where I no longer even think about it; a pot is just obviously 6 inches across, no way you could think it would be anything else, so now I get surprised, rattled, and sometimes even a little cranky (on bad days) when a customer asks me the size of something.
³ Except in the case of Dracaenas, which don't really come back under any conditions, not once rot has begun.
⁴ Is "infection" still the word if the victim is a plant? I know "infestation" doesn't sound right. . . .
⁵ Ethylene is a small molecule produced by some plants, which acts as a hormone. The particular effect varies according to the situation, but the pertinent part here is that in some genera (notably Ficus and Philodendron), ethylene can induce leaves to drop. Ethylene is also produced by some fruit, notably ripening bananas. The 'Xanadu' is on the kitchen table, where there's often a bowl of apples and bananas. So you see the theory. Even if ethylene was part of the problem, the way that the leaves dropped made me think it was still probably more of a watering, dry-air, or Erwinia issue. Might also be worth noting that if it was ethylene, it didn't seem to be present in a large enough concentration to affect any of the other plants in the area, which is another reason to think it wasn't ethylene.
⁶ 'Xanadu' may be an exception to the general rule about watering indoor containerized plants. Ordinarily, one should always water thoroughly, making sure that the soil is completely saturated with water, then drain the excess and place the plant back in its normal location. This is the case regardless of the plant involved, whether it be cactus or Maranta. The identity of the particular plant becomes relevant when you're deciding how fast the soil should dry out, after this drenching, and for how long: cacti, obviously, will rot out quickly if they remain wet, and need a very lean, sandy/gritty soil and a porous container like a clay pot; plants that like more moisture need a richer soil, and can handle a plastic container. And then obviously plants that like to be dry should have longer intervals between waterings. This is an ongoing frustration of mine, because people seem to have the idea that giving plants frequent small sips of water is the way you're supposed to water. But with 'Xanadu,' frequent small sips might be the better way to go, since it is so intolerant of waterlogging. I haven't tried this personally, so I can't promise that it works, but if you've got a 'Xanadu' in decline, this might be something to try.
⁷ Of course, one of the commenters at davesgarden.com also says that "the leaves have a refreshing aroma," which makes me really question whether we're talking about the same plant or not. Ain't nothing refreshing about angry-celery scent.
⁸ (I've gotten hung up on the healthy-plant requirement, unfortunately.)