Episode 321: Peperomia variegation, a top-heavy Homalomena and a fern called Judy
Peperomia argyreia aka the watermelon Peperomia. Photograph: Montrealais via Wikimedia Commons.
Transcript
[0:07] Welcome to On the Ledge podcast. It's a Q&A edition. Your questions answered by me.
[0:18] First things first, I have had in the wake of episode 312, in which I included a little trip in the TTM, the Terrarium Time Machine, a number of questions from you about this wonderful contraption. So I thought I'd just tackle those here because it's not going to be long before we're stepping back into the terrarium time machine for another trip. If you haven't listened to episode 312, then let me give you a very brief introduction to the terrarium time machine. The clue's in the name. It's a giant terrarium that I can use to travel through space and time and visit different planty locations. And in episode 312, we went back to Loddage's Nursery in Hackney, London, to find out that moss poles are not such a new invention, and nor is a love of big tropical leaves. Where and when are we going next? Are we going to be going to the village of broad chalk in Wiltshire circa.
[1:33] 1960 ish if any of you can figure out where we might be going, then give yourself a pat on the back because you're clearly a very well-read and cultured person but for those of you who don't know well you'll just have to wait and find out but in the meantime, yes, terrarium time machine specifics. Some of you wanted to know whether the terrarium time machine was carbon neutral. I would have thought the answer to this was obvious, but just like our plants, the TTM is solar powered. So we are not using anything that's going to cause damage to the environment. And we keep our trips going. Short and sweet to avoid any potential paradoxes, time slips and the like, which are obviously a bit of a risk with time travel.
[2:33] Also, you may be wondering how on earth I managed to fit the entire On The Ledge podcast audience inside a large terrarium. Well, if you've read any of the time machine literature or are immersed in the culture of the time machine, you will very well know, that quite often the inside of the time machine is quite a bit bigger than the outside. And this is the case with the TTM. There's plenty of room for everyone.
[3:09] Some of you have asked about the fern that lives inside the terrarium time machine one of the many plants inside there actually but let me tell you a bit more about her, because she's an icon she's a legend she is the moment and, living in a time machine that's kind of literally true her name is Judy, and she's a bird's nest fern. Now, if Judy was a Boston fern, or maybe a Terrace critica, you know, she could survive being.
[3:44] Semi-sat on by visiting listeners, but she's not. She's a bird's nest fern, and that kind of damage can be catastrophic, which is why we have to be extremely careful with Judy that she doesn't get stepped on because those beautiful, ribbon fronds are delicate and we have to respect her space so that's why I mentioned the fern in the first episode above all things we have to respect Judy so just to put that out there.
[4:19] And one final thing to mention about the TTM that does distinguish it from some other, can I say, inferior time machines you may have come across. Bear in mind that the TTM is made of glass. So when you are traveling through time and space, you will potentially feel a little bit of vertigo because you'll be able to see decades, centuries, millennia. Flipping past you as you go. So just a little tip next time we're traveling. If you keep your eyes on Judy, you won't go far wrong. You will not suffer from any dizziness or time travel related sickness. So yeah, Judy's just the focus and she helps us all to.
[5:11] Arrive at our time travel destinations in good shape, now on to a question from listener Jonathan I would certainly classify Jonathan as one of the OG fans of the show, and I much appreciate that Jonathan thank you for sticking around and Jonathan's question actually comes from his 13 year old son he admits that his kids have got little interest in houseplants he says, other than to sometimes jokingly imply I care more for the plants than them. This is of course not true, but I will note that the house plants never leave their shoes all over the floor.
[5:52] Jonathan, I can relate. I mean, as somebody with one adult child and one older teen, I can contest that it does start to get better and it's all worth it.
[6:05] And just the fact that your child asked a question about a house plant is a really good sign. Now this question in particular looks at the watermelon plant. Ethan, the kid in question, out of the blue at dinner the other night, asked why the watermelon plant has variegation on its leaves, that silvery variegation, and wanted to know what it was all about. Jonathan was interested to know if there was any current hypotheses that I could pass on to his suddenly interested teenager. We're talking here about Peperomia ardurea, the watermelon plant, a very popular peperomia with beautiful with fleshy shield-shaped leaves with silvery variegation that occurs between the veins of the plant which are arranged, in a kind of a starburst pattern so, the first thing we need to know is what kind of variegation is this.
[7:11] You'll note that this variegation is the same from one leaf to another, so it's not like, say, a Marble Queen Epipremnum or a Thai Constellation Monstera. The variegation on those is random and every leaf is different, but on the Watermelon Peperomia it's pretty routinely the same as the plant pushes out leaf after leaf. And it's what we call structural variegation, also known as blister variegation, also known as airspace variegation. I think those are the main three names I've seen given to this type of variegation. And it's not caused by pigmentation. So usually with variegation, we can say that there's a lack of chlorophyll, for example, which might give us a creamy color to a leaf or, a shortage of chlorophyll, which might give us a mint colored leaf or section of a leaf. Or we get red variegation caused by anthocyanin pigments in leaves and combinations of those different pigments give us leaves of different colors.
[8:27] No, indeed, this variegation is caused by a lack of something. So, and the word blister is giving us a clue here there are air spaces in the leaves so gaps between cells which produce this silvery effect when viewed from above i did find a really interesting paper which i'll link to in the show notes, called a revised classification of leaf variegation types which came out in 2020, and this is well worth looking at if you want to delve deeper into the world of variegation because it's got loads of detail. And they split different types of leaf variegation up in by different categories. So they have fishbone shaped, they have blotched, v-shaped, spotted, striped, reticulate and pinnate. And they would class the variegation of the watermelon plant as blotched.
[9:24] And they describe it as the pattern of variegation is blurry and irregular, often located between primary lateral veins or in some species located across the veins. And they found 881 species with this type of variegation. Now, blister variegation does occur on loads of different plants. So we see it a lot in Hoyers. It's what's known amongst Hoyer grows as Splash, where you see these irregular splotches of silvery areas. And again, it's caused by gaps in between cells below the epidermis, below the surface layer of the leaf. And in this paper, there's a microscope image from a species called Sonorilla cantonensis. Now sonorilla are popular terrarium plants so this might be one that you see occasionally in terrarium setups, and if you look at the image you can actually see the air spaces that are creating the silvery areas on the leaf when you look at a cross section of the leaf it's kind of fascinating to see that where the pigments are where the air spaces are.
[10:38] And where the cells with the chlorophyll lay, it's very illustrative of the, idea that leaves can arrange themselves in all different kinds of ways to produce this kind of blister variegation. And the paper makes it clear that different species can have a couple of different types of variegation going on at the same time. So they can have air spaces and they can have pigments going on in one leaf so that you get multiple different effects.
[11:11] And why do these areas of blister variegation look silvery? Well, as sunlight passes into the leaf and moves through these spaces, it causes the light to reflect and scatter about. And to our eyes, that comes out as silver. So we know the type of variegation. It is blister or airspace or structural variegation. And what we don't know is why this plant has chosen or evolved to display in this way. Now, I do mention in Legends of the Leaf, in the chapter on Begonia Immaculata, one theory about blister variegation and its purpose. One is that it mimics damage from pests, particularly the leaf miners, which go under the surface of the leaf and eat out the material there, creating their own airspaces and thus creating this kind of silvery effect. So the theory goes that the plant is creating this kind of variegation so that actual leaf miners think oh gosh that leaf is already occupied I'm not going to lay my eggs there because, I need to find a leaf that's got more real estate for my larvae to work on and there are other theories as well to do with providing a bit of a, sunscreen for plants to protect them from the sunlight by scattering it around the leaf.
[12:39] Those air spaces reflecting and sending the light around the leaf so that the plant is not damaged by the radiation of the sun, because much as plants need the sun, they also can be damaged by too much sun. I don't know the reason for the variegation in peperomia argyrea and I haven't found despite quite a lot of academic paper searches anyone, finding definitively what causes the variegation in that particular plant and it's worth bearing in mind that peperomias as a whole well not all of them have this kind of variegation some of them, have no variegation at all some of them have red, bottoms to their leaves some of them have leaf windows.
[13:26] For example, Peperomia graviolans has leaf windows, which are meant to direct the light in a particular way through the leaf. So, yeah, even within this particular genus, there are different ways of arranging themselves. And we just don't know enough. As far as I can see from the research, I can access to know exactly what's causing the watermelon plant to grow as it does. Bear in mind this plant comes from Brazil, and is going to be growing underneath other plants and is generally growing not in full sun it's usually growing either on the ground or as an epiphyte, covered by other vegetation so that needs to be borne in mind when we're thinking about how it might be dealing with light but also the fact that it is growing in a place with a lot of sun. So I would love to know if anyone has any more information about Peperomia Argyrea and its variegation and the causes. Every day is a school day. And so I'm keeping on learning and hopefully you are too. So Ethan, I'm sorry that it's not a total answer, but hopefully that gives you a bit of an insight into that.
[14:52] Next up, the question comes from Lois, who is delighted to hear that On the Ledge is back on the air. Thank you, Lois. It's great to be back. And Lois, who describes herself as an anxious plant mum, is worried about her beloved homolumena maggie. What a good plant, a really wonderful house plant. And I highly recommend this to anyone who just wants a really nice, big architectural plant that's easy to take care of. And Lois has had her plant for quite a few years and says that it's about four times the size it was when they got it. But unfortunately, all is not well in Maggie's world because Maggie has started to lean over.
[15:42] And the plant, like many of these, is in a cluster and there's separate shoots coming up from a base. And a couple of these shoots have just keeled over. and are leaning right out, to one side and others are bending over. So the beautiful architectural look of the plant is being somewhat spoiled, but worse than that, is Maggie okay?
[16:07] Lois has been working on this by repotting into a larger pot, but the plant's starting to grow sideways and canes that have been tied in aren't helping either. So Lois is convinced that it doesn't have anything to do with light because it's leaning away from the window. And Lois comments, it doesn't get much light at all. As I gather, it grows naturally in dappled shade, but it's never been a problem before. So I'm not sure that's the reason. And Lois also notes that the lovely maroon colored stems that they loved are gone pale green. And there are some pictures which I'll add to the show notes. So what's going on? Lois is convinced it's not light. What do I think? Well, the first thing to say with this kind of situation is that we often, make the mistake when a plant suddenly starts looking miserable of thinking that something has recently happened that has impacted the plant and made a problem.
[17:18] I very strongly suspect in this plant's case that the problem has been happening for a long time and this very tough plant is only now starting to show the signs that it's suffering and I'm going to disagree with you Lois because I think it's all to do with light so the shield plant as homilomena rebessens is known comes from, South Asia comes from, Asia it's native to, Bangladesh and the parts of eastern India, and it's growing on the forest floor underneath.
[18:01] Other plants and trees in a, tropical in a subtropical forest and it's got these beautiful shield-shaped leaves as the name suggests held up on these maroon stems and I think the main thing to say about this plant is that, just because something lives in, and I'm putting big inverted commas around this, in shade in Southeast Asia doesn't mean that it's going to like a very dark corner, in your house because those two types of shade are radically, radically different.
[18:41] And the reason why houseplants are chosen as houseplants is because they can put up with suboptimal conditions for a really long time. In the case of plants like this, they can make do with low light levels for a great deal of time before they start to become affected. But affected, they will be in the end. And in this case, the plant is over time becoming more and more etiolated, more stretched out. Those red stems are losing their pigmentation because of the lack of light. And the ultimate effect for Lois's Maggie is that eventually the plant becomes top heavy and falls over. So what can Lois do? Well, obvious answer is more light. But this has to be done gradually because this plant is used to low light conditions.
[19:34] And will burn if put straight into a south facing window but it could definitely benefit from more light so moving gradually towards a larger window would really help, I used to have one of these not quite in a south facing bay window but not far from it about probably a meter away and it absolutely loved it so you know I would say that you know an indoor window bay window like in my house a 1930s semi-detached house like we have in here in the UK.
[20:08] It could go in that window with some time to adapt and would be perfectly happy the other thing to bear in mind when you're giving more light gradually is that it will need more water, but plants that are in low light will, survive on virtually nothing because they're not really photosynthesizing a lot so my advice would be to lois to gradually get this plant into some more sun uh, you know you're not gonna unstretch those stretch stems but hopefully the plant will start putting out some more compact growth i've seen this, this summer with some tradiscantia some inch plant that i have put into an outdoor pot and it started off the year, with quite long internodal spaces the gap between each sort of, node each section of leaf, but now that it's been outside for a while.
[21:03] Outside not in direct sun but still in much higher light levels those internodal spaces have gone down to nearly nothing.
[21:11] But that's just new growth that's changing the look of the plant so this is what has to happen with the maggie, repotting it won't really help it has to get more light and then the new growth will reflect that in the way it grows and also the, addition of those beautiful maroon stems once more. So I hope that helps, Lois. And good luck with your plant. It's such a good house plant. It's testament to how good a house plant it is that it's done so well in staying alive for as long as it has. But just find the nearest window and get it closer to it. That really is the key. Well, I hope that helps, Lois, and let me know how you get on with your plant. And for those of you who haven't grown a homolomena maggie, I do recommend, provided you give them enough light, they are really good plants.
[22:07] Now, the final question I wanted to answer comes from Jackie, and Jackie, you really made me laugh with this one. Sorry, this has been sitting in my inbox for an inordinate amount of time, but I wanted to come to it because it just made me laugh. Now, Jackie tells me that Norman is a large Dracaena that was rescued 10 years ago from my brother's dungeon.
[22:37] You don't say, Jackie, why your brother has a dungeon, what kind of dungeon it is. But I don't know if I want to know more about that. It sounds a little bit sketchy to me. So we'll just move swiftly on because you tell me that Norman has suffered because you moved house. And this involved Norman being placed on a hand truck and pushed down a long icy driveway, covered like a hostage in a black garbage bag.
[23:08] Poor Norman this sounds terrible I mean I know house moves can be traumatic for house plants but that sounds a lot for Norman to cope with that said Dracaenas I'm guessing this is a Dracaena marginata, although it could be one of the other dragon tree species it could even be if you're up to date with your taxonomy what we used to call a Sansevieria which have now been reclassified as Dracaenas but I'm not sure you don't send me a photo although you do send me a photo of the icy driveway, anyway Jackie's question is this Norman says the least I can do is give him a drink of filtered water as opposed to hard should I indulge are Dracaenas one of those plants that require filtered water he's such a brat, uh well first of all poor Norman I mean indulging him brat I think this is the kind of talk that leads to you, not taking good care of your houseplants Jackie I think houseplants should always be indulged uh where possible and giving them, water that is not hard is I would say going to benefit all houseplants generally uh plants are, Given rainwater, love it. All mine get rainwater because I'm just that girl.
[24:38] But I do take your point. Should filtered water be used instead of hard to keep Norman that bit healthier? If you have a water filter jug, it's fine to use that to water your houseplants. And it will take out some of the chlorine from the water as well as fluoride and heavy metals and mineral salts that can harm houseplants. And Drasenas in particular, yes, they are sensitive to fluoride, chlorine and therefore filtered water might be a good choice. I have a zero water filter, which is rather useful because it comes with a TDS meter, total dissolved solids, which tells me when my water has been completely.
[25:26] Filtered from all of those things that might cause problems to the more sensitive plants. Also useful when I run out of rainwater for carnivorous plants. So yeah I would say filtered water would do Norman some good and, it's not an indulgence but if you can collect rainwater, or even just get some of that snow if it's the right time of year and melt it down and you will be able to use that just make sure it's not absolutely freezing cold um, the issue with dracaenas is also comes up with other house plants it's not going to kill them to give them hard tap water because they're tough house plants see the homilomena maggie story of earlier, but if you want your plant to look its absolute best then yes probably uh, filtered water or ideally rain water is the best for them, And yeah, when you're moving house, plants will always suffer a bit. They're also likely to suffer from the change of location. It might be a good move in that they're getting more light closer to a window, or it might be a bad move in that you're moving somewhere with less light.
[26:43] So the shock of going down that icy driveway will have been felt by Norman. And I mean, living in a dungeon for 10 years isn't going to help either. But Dracaenas are so tough. I'm looking at mine right now and it's not a plant that I spend hardly any time looking after. It officially belongs to my husband and it does absolutely fine. So I'm sure Norman will be OK. But yeah, give him a treat. Give him some filtered water.
[27:13] You know, why not treat your house plants like the kings and queens that they are, Jackie? That's what I would say. But at the same time, like if you're giving them tap water and that's what life allows right now. I'm not going to tell you off for that either, because sometimes life is bigger than house plants. There, I've said it. Oh, and just to say also, because this does come up sometimes with watering. If you have an in-house built-in water softening system, don't use that to water your plants. It's not good for them. It's got a lot of sodium in there, which is not ideal for plants. So again, another reason to get a water bath so that you can use that to water your houseplants. In this current drought we're suffering in the UK, I have seen people talking about using grey water on their houseplants. And much as I would advise trying to get the most out of your water by reusing that grey water, maybe from your bathtub or your washing up sink, I would not use it on your houseplants. Why? Well, because unlike the plants in your garden, potted plants have nowhere to send all of the...
[28:32] Extra bits that are in your grey water so that water is going to contain soaps food debris and that's just going to sit in your plant and make it unhappy at the very least grey water is fine to use outside so I often use it to water my fruit trees in the garden my crab apple and my quince.
[28:55] But I tend to move it around so I don't water in the same place with the grey water every time I move it to different parts of the garden that way you're not overexposing any particular plant to all of the, surfactants and other materials that are contained in soap and so on and that way you can use it without uh affecting your garden too badly, but not on your house plants please with the gray water um i've, yeah i've seen a few things uh of people talking about doing that and it's just, it's not a good idea it goes in the same folder as people using menstrual blood, to fertilize their house plants. It's just it's not a good idea. Don't do it. Why do that when you've got perfectly good fertilizers that you can purchase?
[29:55] You don't have to use that particular body.
It’s a Q&A special! I answer listener questions about the Terrarium Time Machine and its ferny inhabitant, why the watermelon Peperomia sports silvery marks and more.
Timestamps
3:08 Judy, the fern icon
6:11 watermelon Peperomia variegation
14:58 Maggie needs more light
22:06 Norman the Dracaena and filtered water
CREDITS
This week's show featured Whistle by BenJamin Banger (@benjaminbanger on Insta; website benjaminbanger.com) and The Road We Used to Travel When We Were Kids by Komiku.