Asparagus ferns1 are the horticultural equivalent of a blunt object: they can serve a few very important purposes very well, but without a lot of finesse, and they can, on occasion, create more problems than they solve. Around here, they appear in every store simultaneously, at some point during the spring, and then collectively vanish later in the season. We always have some where I work, but I'm told demand is extremely seasonal for us as well.
The main species being sold is Asparagus densiflorus, though I'm not sure if the actual species is being cultivated: almost all of the plants I see are one of two cultivars. 'Sprengeri' is just a big, sprawling mess of a plant, useful for filling in gaps in a planter or in a garden, but I can't say I like the idea of it anywhere else. 'Meyersii' is a little better; its "fronds" have an elongated conical shape to them, making a large, mature plant look something like a bunch of disembodied, cartoony, green dreadlocks. Two other species we have at work in some form or another are A. plumosus (sometimes still A. setaceous) and A. macowanii, neither of which looks all that much like densiflorus. My favorite is A. plumosus, but it has one major drawback, which we'll get to.
These plants are native to South Africa, like a bunch of other common houseplants we've already covered (e.g. Lithops spp., Sansevieria trifasciata, Euphorbia pseudocactus), and share the same tolerance for drought as the others, though I suspect that they're not, any of them, from the same part of South Africa, and they bear no physical resemblances from one to the next whatsoever. Just so you know.
So if I'm calling these, collectively, a fraternity, then what is life like inside of Asparagus House?
Well. Glad you asked. These are big, brutish, potbreaking slobs, by and large.2 They have thick roots, with even thicker water-storing tubers on them, and under ideal conditions, they can grow fast enough to break a pot open or push the plant up over the edge of the pot (this happened with all the hanging baskets in the greenhouse this summer, which were pretty big plants to begin with, so you can imagine the effort involved). They also drop needles by the millions if they ever decide they've gotten too dry: this is a pretty easy situation to avoid, but since they'll tolerate dryness for a long time before they complain, it's easy to forget that they need water.
The absolute worst of the group is Asparagus plumosus, which has such tiny, thin "leaves"3 that if it ever gets a little dry, it explodes into a fine dust of brown particles that can never be completely removed from anything. I mean, I exaggerate, but even so. My personal Asparagus plant is a plumosus that I got from a customer at work, who brought it in, completely brown, looking for a replacement, and then didn't want it back when she found out that we didn't have any to replace it with. I think she left with a Dracaena marginata instead. Anyway. So I brought it home and then cut the plant back to the ground, which was the wrong order: I rode home in the car in a cloud of Asparagus dust and then spent the next six hours brushing cladodes off my clothing. (The plant, incidentally, has come back, but only barely: four stalks since late September, two of which have died.)
But besides being brutish slobs, they're not even nice brutish slobs: they're invasive (A. plumosus is listed here as being invasive on several Hawaiian islands,4 Norfolk Island,5 Lord Howe Island of Australia, and certain islands in Tonga. A. densiflorus has escaped cultivation in Hawaii, Florida, and Australia, and is rapidly becoming a major pest species. A. densiflorus is banned in some or all of Florida – googling was inconclusive on this point, though if you're in Florida and you're thinking about planting this, I'd advise you not to. Even if it's still legal where you live, it's still not a good idea.), they're even more invasive because they can resist certain herbicides,6 and they have nasty, nasty thorns.
The thorns are what tick me off about Asparagus spp. the most. Not only are they unreasonably sharp and backward-pointing (so you can plunge your hand deep into the plant fairly easily – but the only way to get it back is in little bloody pieces), but of course the whole rest of the plant is totally false advertising. With something like Euphorbia trigona, the thorns are right out there in the open, you can see them, and you can consider yourself warned without having to experience the actual pain. Asparagus densiflorus plays dirty, pretending to be all soft and fluffy until it's too late for you to do anything about it. What a dick.
Ordinary people, under ordinary circumstances, can of course just not mess with the plant, and everything will be okay, but for those of us whose jobs sometimes involve having to divide asparagus ferns, in large quantity, over a number of days, things get a lot less fair in a hurry.
They're not as terrible as Agaves, or maybe I'm biased against Agaves right now because one of them stuck me a couple days ago and is still causing me a good deal of discomfort (I think something broke off in my arm, or possibly the wound got infected – either way it's a long-term kind of wound and I find it very troubling.), but they're still pretty bad. If you try to divide enough plants, some of the thorns will stick you and remain in your skin until you get them back out. This is easy enough (I didn't even usually need tweezers.), but it's annoying and unpleasant. It's just not likely to kill you or anything.
Not that they aren't willing to kill things. If they have to. Oh no.
A. densiflorus, at least, produces small white flowers year-round, which may or may not be self-fertile: individual plants are either male or female, as a rule, though occasional hermaphroditic plants, which are capable of self-fertilization, appear. If successfully pollinated, the flowers turn into small berries, which are orange to red in the case of A. densiflorus and dark purple or black in the case of A. plumosus. The berries are toxic to cats and dogs, and maybe some birds as well.7 Human toxicity doesn't seem to be something people worry about a lot, but obviously, if you see a handful of berries take down a cat, and then a dog, you're maybe kind of a little bit of a moron if you save some to sprinkle on top of your breakfast cereal. And anyway, what with the thorns and all, you really shouldn't have these within reaching distance of your small children to begin with, never mind if they're poisonous or not.
Things get even fuzzier when you look into whether the rest of the plant is toxic. As these are closely related to the familiar edible asparagus, we'd expect that the young shoots (the parts of Asparagus officinalis that are eaten) would probably be edible. I'm fairly certain that there's someone out there who has conducted this fairly obvious experiment with asparagus ferns, but I couldn't find any accounts: either people consider it too obvious to bother writing down, or there are never any survivors to do the writing.
I did find someone who had attempted to eat the tubers. The account is from this site (all grammar, spelling, punctuation, etc. sic):
Asparagus plumosus is a noxious weed here in Australia. It produces many small, watery tubers that have a very bland taste. Despite the bland taste, the fact that it grows in such abundance, would make it an ideal wild edible, however.. I can not find any information on its ediblity or constituents (tubers or berries), and therefore would not reccomend it to anyone as an edible. so far we have had no reactions to eat, in the small quantites we've consumed (raw). amongst its bland watery flavour, there is a very very mild flavour of some alkaloid. sorry i could not provide a conclusive 'yes or no' on this yet.
Considering the nasty temperament of the plant in general, I'd say that these are questions best saved for after the economy completely collapses and we are all digging through the rubble of our fallen civilization in search of anything that's remotely edible.8 I don't know conclusively that they can be eaten safely, therefore I recommend you don't try, even if our Australian friend above apparently got away with it.
There's no point to even thinking about eating them if you can't grow them in the first place, though, so let's get on to how to care for them.
A lot of people, at least during the summer, don't really care for them at all: they just stick them outside in semi-shade and let them fend for themselves, bringing them in only in case of imminent freeze. And that can certainly work, but since we're primarily about the indoor plant-growing here at PATSP, I feel like I should maybe be a little more specific. So here goes:
Watering: Asparagus spp. should get dry between waterings; they can get extremely dry between waterings without lasting damage. If they are too dry for too long, of course, they explode into the aforementioned brown cloud.
Light: Bright indirect light or filtered sun is probably best, but full sun isn't necessarily going to hurt anything. Drastic decreases in light intensity will trigger needle drop.
Humidity and Temperature: Indoor growers shouldn't need to worry about either one; outdoor growers might pay attention to when it's supposed to get cold. These are supposed to be hardy in zones 9 and up.
Grooming: Grooming is a pain, and there's not much way around that. Mostly this involves sweeping up dropped needles; once in a while you may be called on to remove dead stems, which if they are very dead will come out with a tug and if they are not very dead may need a pair of scissors. But either way.
Feeding: These are heavy feeders (in keeping with their quick and rampant growth). You'd expect beer, in keeping with the fraternity theme, but no – the only advice I ran into that was specific about what kind of fertilizer just said "high-nitrogen," and "heavy." Since these are reputed to be fairly salt-tolerant, and since they're likely to grow out of whatever pot they're in anyway, I don't see a lot of reason to hold back if you want a big plant.
For propagation we're going to need a bit more discussion. If you have a plant which is lucky enough to have hooked up with another plant of the opposite sex (insert bow-chicka-bow-bow music here), and has produced berries, seeds from the berries are supposed to be pretty easy to germinate. I haven't done it myself, but standard procedure seems to be, 1) soak the seed in warm water for about 12 hours, 2) plant in soil and lightly cover, 3) keep moist. Germination is supposed to take about a month or two.
I'm considerably more familiar with division as a means of propagating plants. The way I've done it at work goes as follows: 1) cut the plant's foliage back to soil level or just above. This is not mandatory, but it makes the rest of the process a lot easier when you don't have to worry about being stabbed over and over again by the thorns. 2) knock the plant out of its pot. 3) use a large, sharp knife to cut the sort of woody, gnarled base of the plant into sections, keeping some roots attached, or else just cut the whole plant in half a couple times and be done with it: both will work but you can get more plants, potentially, out of the first method. 4) plant up the divisions in their own pots, water in, and set in their permanent location.
And that's only if you really want more of them. Personally, I don't know if I'd bother. You'd think demand for a invasive, potbreaking, poisonous, messy, fertilizer-swilling, deceptively thorny plant would be really limited, but apparently if you're suitably fluffy-looking and easy to grow, all is forgiven. [eye roll] People.
Photo credits: mine unless otherwise noted in text.
1 Not that they're ferns in any sense of the word: the name comes from the way some of them resemble ferns a little bit. I can kind of see it, especially with A. plumosus, but it's not a strong enough resemblance that I would have come up with it on my own.
2 I hasten to point out here that I've known plenty of fraternity guys in my time, some of whom fit the stereotype and some who do not. As always, the stereotype, not the reality, is the point for our purposes, however noble, handsome and kind any individual fraternity guy might be.
3 The "leaves" are not actually leaves, of course, because that would be too straightforward. They are instead modified branches called cladodes, and the actual leaves are either the thorns on the lower parts of the stems (according to one source) or tiny, scale-like projections on the cladodes (says another). In fact, according to a third site, they're both right: what are small scaley things near the tips of the stalks turn into thorns toward the base. I suspect #3 is the actual answer.
4 (Lending further credence to my theory that it is always a bad idea to bring any plant to Hawaii, whatever it might be and whatever your intentions are.)
5 (Which is, yes, where Norfolk Island pines, Araucaria heterophylla, come from.)
6 The official line on this is that they are not affected by Roundup (glyphosate), which is one of the most commonly available herbicides out there. One commenter at davesgarden.com said that s/he had found that Roundup still worked, though it had to be applied in specific ways and at specific intervals to be effective.
7 Not all birds. Part of the reason they're a problematic invasive is that some birds eat the berries and thereby spread the seeds. I don't know what method one could use to tell which birds would be poisoned and which wouldn't, other than the obvious.
8 Kidding, but not. I can't help but think that the reason for all the post-apocalyptic, survivalist stories we've been telling ourselves (including, but not limited to: the books On the Beach, A Canticle for Leibowitz, and the exceptionally site-appropriate The Day of the Triffids; movies like Mad Max 2: The Road Warrior, I Am Legend and 28 Days Later, relatively recent fiction like Girlfriend in a Coma or, God help us, the Left Behind series, and non-fiction like The World Without Us; the TV show Jericho, and so on pretty much indefinitely) is that we're cluing in to the fact that we actually can't live the way we have been for much longer without completely wrecking our entire planet, whether the disaster be from nuclear war, global warming, asteroid impact, overpopulation, a new widespread epidemic, or whatever.
The part I find more interesting than that, though, is that we're more interested in stories that assume that yes, civilization is all over, everybody's gone, and we're not so much into stories imagining how we might live differently and prevent disasters from happening in the first place. Even taking into account that the survivalist option is more drama-friendly, I think this is damned odd.
Is this about denial? Despair? Do we all just hate civilization a lot more than we think we do? Do we all want to change a lot more stuff about the world than we normally let ourselves think about, so a chance to really, really start everything over from scratch is super-appealing? Is it just that we're all way egotistical, and therefore too optimistic about our own personal chances of surviving, enough so to be kind of blasé about the other billions of people who'd have to get corpsified in order to live out this fantasy? Don't know.
It really does seem to me like all this disaster porn getting cranked out of Hollywood lately (including and especially Cloverfield, which I thoroughly enjoyed) indicates that something weird is going on with the national psyche, and maybe that of the world. If somebody told you that they'd experienced Cloverfield as a dream, wouldn't you assume some big stuff was going on in their subconscious? I don't think it's even about 9/11 so much: I think we'd be seeing this even if 9/11 had never happened, though I can't prove that.
As usual, I'm good at raising the questions, but not so much at answering them. Not so great at staying on-topic, either. But hey. My blog, my rules.