Saturday morning Sheba and/or Nina picture

I almost came up with a caption for this, but everything was coming out subtly wrong. Feel free to suggest something.

Nothing exciting with either pet this week, though it appears that Nina's Fittonia, the new one with the pink veins, is not going to root. The cuttings I'd tried to start in the basement didn't work either. Perhaps this is not the way to go about propagating Fittonias.

Random plant events: Assorted little things

I'm working on the Schefflera actinophylla profile, but it isn't done. Or close to done. I'll let you know. (UPDATE: Done!)

Meanwhile, I have a set of semi-recent random plant events; they're all noteworthy to me, but none of them seemed quite substantial enough to warrant its own post.


First up, one of the two very tall Cereus peruvianus plants (photo here) has decided to start growing again. I repotted them in October, which might be why. It could also be because the days have been getting longer (the one that's starting to grow is in the slightly brighter spot), or because I added fertilizer with trace nutrients just before the growth started. I don't know.

I have mixed feelings about this, since there's only just so much room left for them to grow, after which point I suppose I'll have to cut them back and start over. I've had them for seven years, so that will be quite the day.


When I was writing the Ananas comosus profile, I found a number of references to the leaves having spines along the margins, but my personal plant, an A. comosus 'Mongo,' has never had any. I assumed that was just a quirk of the cultivar, until a couple weeks ago.

They're not terribly intimidating marginal spines. In fact, they're pretty marginal marginal spines. But the plant remembers how to make them, I guess.


You're not going to think this is exciting at all, but -- I've had this Monstera for four and a half years, and only at the very beginning of its stay here has it ever grown split leaves. I've tried everything I could think of short of putting the plant outside (there's never been a good place to put it), but it's insisted on producing only smallish, unsplit leaves. Until now. Does this mean it's reconsidered, and is going to be making split leaves for a while? I wouldn't bet on it. But we're getting somewhere.


Finally, I'd started some Pedilanthus from cuttings about a year and a half ago, not long after we moved. By now, they're a respectable size, though some of them have been growing horizontally instead of vertically. (This seems to be on purpose, since they're well-rooted and get plenty of light. I have no idea what they're thinking.) This particular plant caught my eye when I was watering because, in the couple weeks since the previous watering, one of its branches has decided to revert to solid green.

The variegated variety is prettier, but I'm going to encourage and propagate this if I can anyway. I don't have a solid-green Pedilanthus yet.

Elsewhere on the Web

What with the shelf rearrangement and stuff last week, I haven't been keeping a running list of links, but I thought this post at Hort Log was worth pointing out before I forgot about it:

Giant gesneriads

Not an exaggeration, either. They're really big.

Pretty picture: Tulipa NOID

Not really part of the orchid show, but these were also at Wallace's on Saturday. I thought the picture came out nicely.

Fungus Gnats: Like Puppies That Try To Fly Up Your Nose

One of the things that eventually drove me away from the Garden Web House Plant forum (GWHPF) was the way people posted the same questions there over and over. It wasn't the same person asking the same questions, obviously, but, you know, you see anybody asking something you've answered thirty times already for other people, and you start to wonder why people think it's okay to ask you to type out an answer for their problem for fifteen minutes, but it's too much trouble for them to spend three minutes searching the archives.¹ Which leads to irritation.

And then my irritation would bleed through and I'd write subtly hostile, cranky responses, which would just convince the person asking the question that everybody in the Garden Web forums was hostile and mean.² I suspect I started writing PATSP partly so I could have a place to link to for questions I'd seen a million times already, rather than spending half an hour answering them all over again from scratch.

By far, the most frequently re-asked question at the GWHPF went something like, HELP!!!1!!!1!! I just bought this plant and I don't know what it is but there are all these fruit flies flying around it all the time and this is the worst thing that has ever happened to me so please please please can somebody tell me what to do to make them all die because they are ruining my entire life!!1!!!!!1eleven!! (And yes, some of them were actually that dramatic. You would be amazed.)

So.


First, don't panic. Or, if you'd already started panicking, please stop, 'cause it's annoying to read anything with that many exclamation points.

Second: they're not "fruit flies," (Drosophila) they're fungus gnats (Bradysia). I realize you probably don't see a difference or care, but you have to know your enemy in order to defeat them.

Where do they come from? Most likely, they came in with a recently-purchased plant. If you haven't brought in a new plant, but you've repotted something recently, then your potting soil probably contains gnat eggs. Miracle Gro potting mixes in particular are consistently about 67% gnat eggs by weight,³ but gnats are a risk you take with any high-peat mix.

Why? I dunno. They just like peat, I guess.

What do they want? The adults lay eggs on wet soil, the eggs hatch into larvae, the larvae eat (mostly decomposing organic matter, not necessarily fungus per se), grow, pupate, and then they're transformed into beautiful . . . fungus gnats.⁴ Adults don't eat,⁵ so they don't live very long: they're focused on mating and laying eggs. Since the survival of the eggs depends a lot on moisture, adults are very interested in things that strike them as potentially wet. Which means that sometimes, they will try to fly up your nose or in your mouth. Also one will occasionally find them drowned in unattended cups of coffee, or hovering near sinks.

Are they hurting my plants? Probably not. The larvae are capable of feeding on the fine root hairs of plants, but even if they do, this would only harm plants that were very young or very weak. Living tissue is probably not their first choice anyway.

How do I make them go away? You have many options here, with varying levels of ease, expense, and effectiveness.

Personally, I would recommend either watering less often or doing a soil change. If the soil the larvae are in goes completely dry, they die, and then you don't have a next generation of adults. It may take a while, especially if you have a lot of plants, bring home new plants often, or have a lot of plants that will die if they get too dry, but if you're consistent and patient, it should happen.

Letting plants dry between waterings is what I personally do. I bring in new plants often enough that we usually have a few fungus gnats around at any given moment, but considering the number of plants here, a few is as good as none. And honestly, I kind of like them.⁶

Soil change can be thorough (shake off every bit of soil from the roots and replace with all-new soil from a brand-new bag) or partial (shake off some of the soil and replace it with a faster-drying mix, like potting soil cut with perlite, coarse sand, aquarium gravel, aquatic soil, etc.). Thorough soil replacement may be more stressful for the plant, but it should stop the gnats immediately, assuming the replacement mix is clean. Partial replacement is easier on the plant, but won't fix the problem as fast. Some of the old soil will still be there; it'll just be drying out faster.

Another option: sticky traps. I don't like sticky traps. They sound good in theory -- they're just pieces of yellow cardboard with adhesive on them. Gnats land on the cardboard and then can't fly away again, so gradually you wind up with fewer and fewer gnats flying around.

In my personal experience with sticky traps at work, mostly the traps stick to leaves and hands, not to bugs, and when they do function as advertised, you then get to look at a brilliant yellow piece of cardboard that's covered in dead insects, which . . . makes a statement, certainly, but I don't think it's going to catch on in New York.

Soil drenches are another option. If you're going to go this route, a product based on Bacillus thuringiensis ssp. israelensis, or "BT," is probably the way to go. Some brand names are Gnatrol and Knock Out Gnats; several "mosquito dunks" also use BT and can be used instead, if you don't find gnat-specific preparations.⁷ BT is a bacterium that produces a protein which screws up the larvae's digestive systems and kills them. It's organic and safe around people or pets. One may have to re-treat once or twice before the gnats completely go away.

Several people at Garden Web swear by the potato method, which is: slice a potato in half. Lay the cut end on top of the soil. The fungus gnat larvae will find the potato, get excited, and start chowing down. After a few hours, you can pick the potato back up, with all the larvae now on it, and throw it away. Or you can slice off a section and put it back on the soil again. I'm not sure this is sufficient to eliminate a gnat infestation all on its own, but it might speed up the process if you decide to reduce watering, and the more larvae you can get rid of, the fewer adults you have to see.

A simple and fairly cheap solution for small houseplant collections: spread a thin layer (maybe 1/4 inch or 6 mm) of coarse sand on top of the soil in your houseplants. The adults can't get through the sand to lay eggs, and the larvae can't get through the sand to become adults, so the problem disappears in one generation. Plants so treated will stay wet longer, since water will have a harder time evaporating from the soil surface, but I suppose one could always scrape the sand back off again after two or three weeks, if it's really a problem.⁸


Actual pesticides like pyrethrins, imidacloprid, etc. are not, I think, necessary, nor will most of them even be effective, either because of their targets (if the label doesn't specifically say it will kill fungus gnats, it probably won't) or their mode of application (pyrethrins have to make direct contact with an organism to kill, and break down quickly -- they're useless for a fungus gnat larva an inch below the soil). There might be a role for a soil drench of neem oil with dishwashing liquid, if you're going to insist on a pesticide, but I think the other methods will probably work just as well as poison, and some of them are very cheap and easy. I mean, technically, watering less often should save you money. Just not very much of it.

That's pretty much everything I know about fungus gnats and what to do with them. If there's something I haven't covered, or if there's something I did address that you think I got wrong, feel free to leave a question or comment. Alternate methods of dealing with fungus gnats are welcome too.

-

¹ Of course, the people posting questions sort of are being responsible and doing their own research, in a way -- if you have a plant problem, it makes sense to go to a plant-related forum to ask somebody about it. And if you've never been to GW before, you might not be able to appreciate how big it is, you might not be able to locate the search field, you might try to search and wind up getting gibberish back, if GW's code is being glitchy.
Really I was the one with the problem. I wasn't responsible for answering fungus gnat questions, and if I didn't want to answer them, then I could have just not answered them, rather than making it all about me and getting upset.
² Which, last I checked, was mostly true, actually, but it wasn't always that way, and it certainly doesn't have to be. The dynamics of online communities is perhaps a topic for another time.
That, plus feeling obligated to answer people's questions even though I wasn't, made it sort of a bad place for me to be, overall, and I'm glad I'm done with posting there. I do go back every few months to look around. Sometimes I look to see if I can find a blog topic, though I don't remember that ever actually working out.
³ (Exaggeration for comic effect; I'm sure it's less than 20%.)
⁴ Not every ugly duckling becomes a swan, yo.
⁵ (Pretty sure I read this somewhere at some point.) (UPDATE: Aralia left a comment with a link saying that this isn't true; adult fungus gnats do eat. So never mind.)
⁶ Yes, it's alarming to inhale one accidentally, or have one flying around your face for a few seconds like it's trying to figure out how to get in, but it doesn't actually hurt you. I mean, if you inhale a gnat, you're definitely getting the better end of that experience.
Around here, they come and go -- we are presently having a high-fungus-gnat period, which is why this post -- but I kind of think they're cute. Like puppies! Puppies that try to fly up your nose!
⁷ The difference, as I understand it, is that mosquito BT is made to dissolve slowly, over a long period, to kill mosquitoes that attempt to lay eggs in whatever body of water the "dunk" is sitting in, while gnat BT is usually either made to be dusted directly on the surface of the soil or made to dissolve more or less immediately in water. I'm fuzzy on this, though, having never used either product, and I've only occasionally seen the mosquito dunks.
⁸ This might be the place to note that decorative moss or stones on top of the soil will also keep the soil wetter longer. If you have such items on your soil, you should take them off at least until the fungus gnat problem is resolved. (I would actually advise not putting them back on again ever, but that's just me.)

Random plant event: Furcraea foetida offset

Happy Pi Day!

I'll admit that today's subject isn't a particularly exciting photo, but it's one of those cases where what it represents is exciting. This plant had been growing in the parent plant's pot for quite a while; I first noticed there was a pup last May.

At some point this winter, I noticed that it didn't seem to be doing so well -- the parent plant and I haven't figured out this whole winter-watering situation yet. I let it go for a long time, then water, but then when I water, a leaf or two will yellow and die. I haven't figured out whether that's because I watered, or if it's because I let it get really dry first. It's usually grown outdoors, so there's not a lot of information out there about how to do it indoors.

Anyway. So at some point I noticed that the pup seemed to be doing poorly, more so than the parent, so I pulled it out and gave it its own pot. I didn't figure the two-leafed pup would survive the winter -- bad time to transplant, it was already stressed -- but it seemed to be needing more water than what it was getting.

The news today is that the offset is growing a third leaf:


It's still tiny, obviously (the pot is 3 inches along the diagonal), and it's not clear that it's ever going to grow huge, healthy leaves like the parent, but at least it's growing, and I can still have hope that it will grow huge, healthy leaves someday. Considering that I was pretty sure I'd killed it by moving it, that's pretty good news.

Pretty picture: Paphiopedilum esquirolei

So. Went to the orchid show yesterday (it's still going on today, should you happen to be in or near the Quad Cities; check Wallace's Garden Center for hours and directions). I had a surprising reaction to it: I was disappointed.

I don't know why exactly. Some of it may have been that last year, I had basically no expectations (never having been to a plant show before), so what they had was surprising and impressive. This year, I remembered last year, and how it was surprising and impressive, so when it wound up being pretty similar to last year, I was disappointed. Expectations ruin everything, I tell you what.

Quite a few plants I remembered from last year were back again, too. I realize that it's unreasonable of me to expect the people putting the show together to get entirely new plants every year just for me, but I was, again, kind of disappointed. In a few cases, I maybe got better pictures than what I got last year -- as I write this, I haven't looked through all 322 photos I took to see how they turned out, though. Some of the preview photos on the camera display didn't look so hot. We'll see.