Sunday, April 27, 2014

Random plant event: NOID NOID

The scale infestation continues. It is in fact looking like what people say is true: once you have scale, you always have scale. It's never very many insects, they're never on very many plants, I can occasionally even remove an infestation from an area entirely by repeated spraying with rubbing alcohol.1 But it always seems to move somewhere else, and always seems to return to the plants I removed it from. Between the scale and the sunburn and rot caused by putting plants outside before they were ready, I'm on the verge of throwing out all my Agaves, Furcraeas, Manfredas, and Mangaves and being rid of those genera forever, the same way I abandoned Hedera and Codiaeum to the spider mites years ago. I mean, look what happened to my Agave lophantha 'Quadricolor' after two days outside:

September 2013:

April 2014:

I did salvage an unrotted offset from it, and I had a previous offset (taken over a year ago, when I'd thought the scale might lead me to throw the plant out), but that's small consolation for losing a specimen as large and pretty as it was. Especially since the offsets will likely die or get thrown out before reaching that size themselves.

But we're not here to mourn the Agave; we're here to marvel at the recuperative powers of my NOID fern.2

I discovered scale on several of the fronds around the beginning of March, maybe the end of February. I started cutting off any fronds that had obvious scale, and any fronds that were close enough to have had honeydew dripped on them. As I progressed, I realized that 1) this would result in me cutting off most of the fronds, and 2) any fronds that I left would probably have enough undetectable scale on them to launch a new round of infestation, so I'd have hacked my fern to bits but accomplished nothing. So, I cut all the fronds off down to the rhizomes. Maybe the plant would come back, maybe it wouldn't, but at least the scale would be gone.3

I'm not certain about the date, but my best guess is that I cut the fronds off on 28 February. By 18 March, new ones were coming up all over:

And by yesterday morning (26 April), it was back to what it had looked like before, pretty much:

That's an incredibly fast comeback.

I don't know yet whether this had the intended effect of getting rid of all the scale. I haven't seen any yet, but then I've also been too busy and too scared to look for it. I'm impressed with the plant's recovery either way, though.


1 If you want to recommend that I try pesticides, especially imidacloprid: been there. Done that. More than once. It costs too much for something that works as slowly and incompletely as it does.
2 It was a hitch-hiker in a Rhipsalis I bought years ago. Took it out, nursed it along, and it is now much, much larger than the Rhipsalis ever dreamed of getting. Because the fern wasn't supposed to be in the pot, though, there was no ID for it. My best guess is that it's a Phlebodium of some kind, possibly P. aureum. When I expressed this opinion in a previous post, someone popped up to tell me that it was cleeeeearly a Hawaiian wart fern (Microsorum scolopendria or Phymatosorus grossus) and not a Phlebodium at all. Based on the lack of scent (M. scolopendria fronds are supposed to smell like vanilla.) and the less-orderly arrangement of its spores, I'm pretty certain it's not that particular Microsorum (or Phymatosorus). Though I don't rule out that it could be a Microsorum (or Phymatosorus).
3 In theory. I was assuming that the scale wouldn't be able to survive on the hairy rhizomes long enough for the plant to grow new fronds. This may or may not be a good assumption.


Anonymous said...

Too bad about that agave. It's a hazard of having them inside all winter and then moving them out for the warm months. They seem to lose something during winter and react badly even if the foliage was initially grown outdoors. May not entirely be from the sun, though. I find aloe vera and sansevieria will collapse in the middle of the leaves like in your photo when moved outside if overnight temps drop below 50F. Even if they aren't exposed to sun. Which is weird because exposure to the same temp drops in the fall have no effect. At least that seems to be the cause of the collapse.

Texas Anon

Paul said...

Ferns are weeds, IME. Not surprised at all that it came back from being leveled.

Sorry to hear your scale battle continues ... albeit on a smaller scale than before. (Play on words intended. heh) Though if the scale keep reappearing on the same plants, at least you know which ones to check.

Man, that is tragic about that agave ... though, let's be honest, you have no one to blame but yourself for any sunscorch or freeze damage. Plants need hardened off -- you know better.

danger garden said...

Oh the poor agave...

mr_subjunctive said...


I thought I was hardening it off, though, is why it hurts. It definitely didn't get exposed to any temperatures below 50F, it wasn't out for more than 36 hours, and it was in a spot where it wouldn't have seen much direct sun. My mistake, I presume, was in leaving it out for such a long stretch at all, even if the conditions seemed pretty moderate. Last year, I was doing stuff like moving everything out for two hours in full shade and then bringing them back in, then three hours in full shade the next. That seemed excessively cautious to me at the time, but I guess it wasn't.

Wade said...

I agree, it looks like Phlebodium aureum (formerly Polypodium aureum). That species is a very common and agressive greenhouse weed, so it's not surprising that it was a stowaway on a Rhipsalis.

Julie said...

I thought I got rid of scale once with just spraying with soapy water? No??? I thought so, but I'm getting old and can't remember for sure! I want to say I did though!

Anonymous said...

I'm sad for you that the scale is still there. Maybe it would help if you write a post detailing what exactly you've done so far and the hive mind can help come up with other ideas.

Is there anyway that you can isolate the plants that have scale or are at risk of haboring them? Im thinking of things like putting them at a friends house temporarily, your husbands office, a makeshift greenhouse in the backyard. Once you have all the infested plants isolated then maybe you can truly eradicate it instead of plants passing it back and forth.

I'm also wondering if you have tried soaking the plants in a solution of alcohol or insecticide to make sure scale can't hide in any nooks or crannies.

As a last resort, maybe you could use this summer as a chance to spray stronger insecticide on the infected plants outdoors. Like I'm talking get suited up and put a respirator on chemicals. It is drastic but man you've been dealing with this for so long. I know I would have a hard time enjoying my plants with this going on.

mr_subjunctive said...


I appreciate the sentiment, but after trying to write out the details of what I've done several times, the ways in which none of it has worked, and the ways in which your suggestions are not practical given the size of the collection, I am moved to despair and don't want to think about the scale anymore.

The most effective approach for me so far is: 1) if a scale-affected plant can be thrown out without anguish, throw it out, and 2) if a plant is affected by scale but cannot be thrown out without anguish, spray all surfaces of the plant with 70% rubbing alcohol a couple times a week, with optional hand-wiping of the leaves with a paper towel afterward. This doesn't remove the scale from the collection entirely, but it keeps the problem manageably sized, is less expensive than imidacloprid or other insecticide-based approaches, and is occasionally successful in removing the scale entirely, which is better than the imidacloprid ever seemed to do.