Dracaena marginata is right up there with Spathiphyllum cvv. and Sansevieria trifasciata as a common indoor plant that everybody grows at some point, but almost nobody ever grows well. A lot of this is because of the way they're sold: they're a common component of mixed "tropical plant" containers, where they are typically planted with things that need entirely different care,1 but even when they're on their own, retailers tend to portray them as good, dependable, low-light plants that are super-easy to take care of.
And they kind of are super-easy to take care of. Or at least they're about average.2 But there's the kind of super-easy that means you can do whatever you want to them and they'll be fine, and there's the kind of super-easy that means that their very specific requirements aren't hard to meet and mostly involve pretending that the plant isn't there. Dracaena marginata is firmly in the latter camp.
Hence our "person" for this profile. Dracaena marginata is the plant that gets blamed when people say they can't grow houseplants, it's the first plant in a group planting to die,3 it's the six-foot-tall (2 m) stick with the tiny tuft of limp leaves at the top that nobody wants to look at but won't throw out, either, for fear of feeling guilty.
I was unable to find much trivia: they're native to Madagascar, and according to Lynn P. Griffith (see sidebar for who he is), they're called "money tree" in Hawaii, because the first ones brought to Hawaii were planted around the Bank of Hawaii. Which is only just barely interesting. The usual common names are "dragon tree" and "Madagascar dragon tree."
I'm not aware of very many cultivars, but there are a few:
- 'Tarzan' is similar to the species but with larger leaves, slower growth, and supposedly more reluctance to drop its old leaves. The odds are pretty good that any floor-sized specimen of a green D. marginata you encounter is a 'Tarzan,' though the species is still sold here and there.
- 'Magenta' has wider and darker marginal stripes on top of the green: despite the cultivar name, they're not magenta in any sense of the word. Dark purple, maybe.
- 'Bicolor' is a slower-growing variety with mostly cream-colored leaves, which have green and pink stripes.4
- 'Colorama' is the only variety I personally own, and was the hot seller at work as well: its leaves are pinkish red with a few green stripes underneath. New growth on 'Colorama' is sometimes slightly cream-colored.
"Character" plants have been manipulated so that the different canes grow in different directions, with crooked stalks, and are more interesting to look at (in my opinion) than the strictly vertical plants, but they also take up a lot more room, and not everybody is a fan of long stretches of bare cane. I've also seen plants with stems that had been tied in an overhand knot. I don't understand why anybody thought that was a good idea. (No pictures, alas.)
Care for any of the varieties, sizes, or shapes is essentially the same.
LIGHT: Though often listed as a low-light plant, and although they will tolerate low light for a while before showing any ill effects, this is not a low-light plant and should not be treated as such. Plants which are not getting enough light will produce small, limp new leaves.
Outdoors in tropical areas, they can be grown in full sun; however, the plants you purchase as houseplants are usually shade-grown, to prepare them for indoor light levels. Plants so grown will burn up and die if suddenly exposed to long periods of full-strength, outdoor sun.
I also don't recommend full sun, or even afternoon sun, for indoor plants. Direct sunlight seems to be a spider mite aphrodisiac.5 Filtered sun, a couple hours of morning sun, or bright artificial light should be fine, though.
WATERING: Sites talking about Dracaena marginata as an outdoor plant will tell you it needs a lot of water, and to keep it moist. If you're keeping one inside, forget this completely. I probably shouldn't even have mentioned it.
This plant is very easy to overwater. Never ever ever ever ever leave it to stand in drainage water or put it in a pot without drainage holes. Soil should be very quick to drain (no peat!), and don't water if the soil feels even remotely wet, as far down as you can get a finger. This is especially important if the plant is in a large pot, and super-especially important if it's in a large plastic/glazed/ceramic pot: soil can stay moist at the bottom of such a pot even when the top is very dry. When in doubt, don't water.
Ignoring the above advice is just begging for a visit from the Fusarium fairy. Whom you do not want to meet. (see PESTS)
HUMIDITY: See PESTS.
TEMPERATURE: No colder than about 60F (16C) or warmer than about 95F (35C). Plants that are exposed to temperatures below 60F/10C are not necessarily dead, but it's more dangerous to the life and appearance of the plant the colder you go. Cold temperatures are more dangerous if accompanied by extremely dry air or high winds. (Also the case for other Dracaena spp.)
If you have exposed your plant to extreme cold, there's really nothing you can do except get it back to desirable temperatures as quickly as possible and hope it forgives you.
PESTS: This part's going to be long, so brace yourself.
Most Dracaena species are pretty good about pests, in my experience, but not Dracaena marginata.7 They're especially bad about getting spider mites, but I've also recently spotted plants with mealybugs at multiple garden centers in my area. (They all looked like 'Tarzans,' too, by the way.) This could mean that there's a single supplier somewhere in Florida that's having a really bad mealybug infestation right now, or it could mean that mealybugs are a bigger problem with D. marginata than what I had previously thought. Either way, it's a good idea to watch your plants for signs of infestation, and check plants carefully before you buy them. Neither spider mites nor mealybugs are particularly easy to eliminate entirely, though spider mites can be kept under control by spraying foliage with soapy water and giving the plant a good shower every so often.
Also, overwatering tends to bring on bacterial and fungal infections. The most common bacterial infection for D. marginata in my experience is Erwinia, which produces mushy stems with a horrible odor. (Seriously. The worst smell I have ever smelled in a houseplant-related context was from a D. marginata cane at work that we'd been trying to propagate. I tore the stem open and got hit with a blast of . . . well, it smelled like pain. The only specific comparison I remember is "ammonia." The rest of my impressions were, I assume, wiped from my brain as the noxious gases dissolved the responsible neurons.8)
This was probably brought on by us keeping the cane too wet while waiting for it to root. Erwinia is not usually a problem indoors: it needs very moist conditions, and tends to happen primarily during propagation (when the plant is injured and more susceptible to infection), Griffith says.
With Erwinia, by the time you smell the smell and feel the mush, the plant is probably already too far gone to try to save.9 If there's a non-mushy section near the top of the cane, you can try to cut that off with a clean knife and root the top (see PROPAGATION), but you're probably best off to cut your losses and throw the whole thing out, rather than try to save it.
A fungus called Fusarium oxysporum is much more common indoors, and also caused by overwatering. With Fusarium, the plant will continue to look more or less fine, except for a dark spot on the cane. The dark spot is subtle: it's not an oozing black mess or anything, just a slight darkening at one particular point, usually about halfway up the stem. As things progress, the stem gets slowly and invisibly hollowed out, leaving just a thin layer of bark. The top of the plant will continue to grow, albeit a little sluggishly. People typically don't notice anything is wrong until they happen to grab the cane and feel a weird hollow spot, or the stem actually bends over.
There's not really any treatment for Fusarium either, though it's slower, so the odds of being able to salvage something are higher.
PROPAGATION: The most typical way (maybe the only way) to propagate D. marginata is by taking a tip cutting. Planting a cutting directly into soil is, in my experience, a good way to lose it to Erwinia, but damp perlite or vermiculite make good rooting media for a lot of things, and are sterile,10 so one might try that. I've never water-rooted this particular plant, though I've done so for similar and related species (Yucca guatemalensis, Dracaena fragrans) and had that work out relatively well.
Whatever you decide to root it in, to get the cutting, just take a clean, sharp knife and cut straight across the cane, then stick the cutting in whatever rooting medium you've chosen, and wait. With water-rooting, you'll be able to see when roots begin to grow, and you can pot the cutting into soil, preferably in the smallest pot the roots can fit into, once the roots are a couple of inches long. With perlite and vermiculite, wait a couple months after planting, keeping the medium damp but not soaking wet, then gently pull the plant out to see if it has roots (it very likely will). If it does, you can plant it in soil immediately.
Air-layering is also done with this plant, I'm told, but I've never air-layered anything and don't want to explain how to do it. So I won't. It's my blog and you can't make me.
GROOMING: Something that occasionally freaks out D. marginata owners, especially owners of large, floor-sized plants, is the appearance of clear, slightly sticky droplets on the underside of the leaves. This will usually be mostly on the topmost leaves, not all of them, and the droplets themselves will be close to where the leaf attaches to the stem. I don't have pictures, sorry.
This is just guttation. It doesn't mean much, though one should keep an eye on plants that do this because 1) it may indicate overwatering, and 2) insects (particularly ants, Griffith says) are occasionally attracted to the droplets.
It's normal for a few leaves to drop every so often, as the plant grows, so there is a little actual grooming required occasionally.
Plants also have pretty thick, quick-growing roots, and will typically need to be repotted every year or two. Don't repot just because the year is up, though: make sure the plant actually needs it.
Plants that have gotten too tall for their space (Depending on who you believe, mature plants can get between 6 and 20 feet tall, with most sources saying 10-15.) should probably be cut back and/or air-layered. This is kind of a high-class problem to have, since most Dracaena marginatas don't get old enough to outgrow their space.
FEEDING: Feeding is sort of a tough topic. Outdoors, Griffith tells me that these are fairly heavy feeders, but indoors, a lot depends on how much your plant is actually growing. There's no point in supplying nutrients that your plant isn't going to use, and Dracaenas can get tip burn from excess fertilizer, so too much is actually worse than not enough.
My recommendation would be to go with a normal houseplant fertilizer, ideally something with a 3-1-2 NPK ratio11 and micronutrients,12 and mix at about 1/4 of the strength recommended on the package. I don't follow this advice personally, because for reasons of historical accident, cost, and convenience, I currently use a 14-14-14 time-release Osmocote fertilizer on everything. (It's a long story, and nobody ever believes me once I reach the sentence that starts "So Scott Baio is all, 'I thought you were going to spray-paint the goldfish, and I was going to hold them down,'" so I'm going to skip the retelling. Another time, perhaps.)
I suspect this profile makes D. marginata sound like a bigger pain than is actually the case. I have seen a lot of plants that got mealybugs, spider mites, or Fusarium (in fact, probably 90% of the specimens I've seen with a problem had one of those three), but I've also seen plenty that didn't have any problems at all, and my own personal plant at home has never really given me any trouble. I'm just not a huge fan of the way the plant looks,13 and I was also frustrated by the way the customers at work always seemed to settle on either one of these or a peace lily, even when shown plants that were way easier or more interesting. The customers' behavior isn't really the plant's fault, of course. But it's tempting to blame the plant anyway.
Photo credits: All mine, except the one from BotBln.
Another site of interest: http://www.hear.org/starr/plants/images/species/?q=dracaena+marginata (many pictures of outdoor-grown plants, including inflorescences)
1 The point, with a mixed planting, appears to be to cram a pot full of a number of different plants in a way that resembles a flower arrangement. Which is to say, the point is not whether they are mutually compatible plants, but whether they fill up all the available space and fit a certain kind of stereotyped, overfull look. Generally there's a tall thing, a trailing thing, and a medium-height thing, one or two of which may also contain some kind of non-green color which matches, or at least harmonizes with, the pot. Dracaena marginata, when used, typically fills the "tall thing" spot. The pots for group plantings typically have no drainage either, making the whole situation a death trap for any plants involved.
I dislike pretty much everything about group plantings of indoor plants. I don't like the concept, I don't like the execution, I don't like the aesthetic. I mind less with outdoor group plantings, in large part because from here it looks like it's easier to match cultural needs for outdoor plants, and also because outdoor container plants usually aren't expected to stay together for more than a season. Though outdoor group plantings still often look crammed full of plants in a way I don't like.
2 "Average" difficulty, as measured by the PATSP difficulty levels, is consistently in the range of 3.5 to 4.0, though it varies slightly depending on which average I use (mean / median) and whether I'm looking at the original set of numbers or the expanded set I came up with recently. Dracaena marginata, at 3.0, is slightly to the easy side of average.
3 Because the tendency is to kill new plants by overwatering and old plants by underwatering, the plant that's most sensitive to overwatering in any group planter is generally the one to kick first.
4 'Bicolor' sounds like it would be pretty, from that description, but I'm not a fan: unless you're right up next to the plant, all the narrow stripes of color blur together into the average of cream, green and pink, which is sort of a tan.
5 It's actually probably more the heat sunlight generates, instead of the light itself. Spider mites love heat. (They are adapted to the conditions in their native habitat, which is Hell.)
6 Unless you're an ant, in which case some of them do shoot candy out of their butts.
7 Dracaena thalioides, sad to say, appears to be another one of those: my plant at home has been having ongoing troubles with spider mites since I bought it in June, and those troubles have gotten really serious since I stopped being able to take it outside to water. I'm told the other specimen they brought in at the same time at work (which has since sold) also had an ongoing spider mite problem.
8 "Did I fall asleep?"
"For a little while."
"Shall I go now?"
"If you like."
9 (And if you've smelled the smell, there's a good chance you're pretty far gone yourself.)
10 One warning, though: perlite does usually contain some fluoride, to which Dracaenas are sensitive, so if you're given the choice, go with vermiculite over perlite. If you don't have a choice, wash the perlite first by putting it in a colander or strainer and running cold tap water through it for a few minutes. It won't work miracles, but it's better than using perlite straight from the bag, and also makes it a little less dusty to work with. Distilled or reverse-osmosis water would be even better than tap water, but they're also a lot more expensive than tap water.
If it helps, D. marginata seems to be a little less touchy about fluoride than D. deremensis varieties or D. fragrans.
11 NPK ratio: the three numbers on a package of fertilizer which tell you what percentage of the product is nitrogen (chemical symbol N), phosphorous (P), and potassium (K), respectively. They should be prominently displayed somewhere on the packaging.
Theoretically, any numbers that total less than 100 could be used, but in practice, most fertilizers sold for houseplants have ratios of either 1-1-1 (most commonly 20-20-20) or 3-1-2 (usually 24-8-16).
12 Some fertilizers will contain, in addition to nitrogen, phosphorous, and potassium, trace amounts of various micronutrients like iron (Fe), calcium (Ca), copper (Cu), manganese (Mn), boron (B), and sulfur (S), though these are present in much smaller amounts and are reported differently on the packaging. Micronutrient deficiencies are rare in indoor plants, though they're not unheard of, particularly iron deficiency. I keep meaning to write a post about this, but it has the potential to be really technical and contentious, so I've been putting it off.
13 'Colorama' gets a pass because of its color, which I find pleasant, especially when backlit. I also came close to buying a small 'Magenta' while writing this, but managed not to. Yay me.