Transcript

Episode 160

[music]

Jane: Hello, I'm Jane Perrone and every time I type the word 'houseplant', it comes out as 'houselpant'! The struggle is real, people! Hello! Welcome to On The Ledge podcast episode 160. How are you all doing? This week, we will be looking at plant pigments with Professor Nox Makunga, as the latest instalment in my leaf botany series, and I'll be answering a question about a Silver Ripple Peperomia, plus we'll be hearing from listener Mia.

[music]

Jane: How has your week been? Mine has been variable to say the least, I've been suffering from ABC - that's 'Another Bloody Cold', no doubt caught from my children's return to school, so I've been getting through quite a few boxes of tissues here at On The Ledge towers! In exciting news, my Legends of the Leaf crowd funder is now at, let me just check this, I don't want to give you wrong information, 36% and 220 supporters, so if you're one of those 220, thank you very much indeed for your support. As I've said before, this book means a lot to me, and I really want to make it happen and I hope you do too, so do spread the word about the book. If you can't afford to pledge yourself, then maybe tweet about it or stick up an Instagram post or story, or why not phone a friend and just tell them about the book?

Thank you to Sophie who got in touch this week to tell me what the basic in "basic slag" means. You may remember, from part one of the potting mix ingredients episode, that I talked about the mysterious ingredient called 'basic slag' which I found referenced in a book about epiphytic cacti. Well, it turns out that the basic, according to Sophie, refers to the pH of a substance, more commonly called acids and alkalis now, but an older way of describing them is bases and acids. So the basic in the name is telling you slag is alkaline in nature. Isn't that useful? That's really handy to note, Sophie, so thanks for leading me in on that. Sophie also got in touch about the Meet the Listener question. She's not too keen on the new Mars question because she says, "I just think if I were to take a plant to Mars, I would have to choose something useful or edible. There just wouldn't be space for anything else!" Well, I was assuming that you would have some on-board farm, which would be providing for your immediate physical needs and the houseplant you'd be taking would just be a little bit of an extra for your own mental wellbeing. Sophie has come up with a brilliant alternative question about Dr Hessayon, who is the author of 'The House Plant Expert'. She suggests, "If Dr Hessayon dropped by unexpectedly for coffee and you only had time to show him one plant, what would that be?" Sophie, that's an evil question because, of course, if Dr Hessayon did pop round for tea, one: I would have already fainted by this point with excitement and two: what on earth would I pick? It's a really great question, Sophie, I'm going to stick with the Mars question for the moment, but as I said in my email reply to you, I will change all the Meet the Listener questions at some point. Perhaps we'll set up some new ones for 2021 and I think your question is a great contender for the 2021 questions, so thanks very much for sending it in.

Thank you to KiwiGardenerGuy in New Zealand who left a lovely review for the show on Apple Podcasts, and to Alannah, who says she can't leave a review on Spotify because it's not possible to do that, but if she could she would leave a five-star review. Thank you very much, Alannah! She's been listening for about four or five months now and it's her "Absolute favourite podcast ever!". I feel very honoured! Her four-year-old son has taken a huge interest in houseplants too and has picked out his own plants: a pink Kalanchoe and a Nepenthes. That is awesome that your four-year-old is getting into plants! It sounds a bit like me as a child. That was definitely where I fitted in. Have I got any younger listeners than four-year-olds to On The Ledge? I suspect not, but if I'm wrong, do let me know!

I got a message from Catarina who is referring back to part three of potting mix ingredients episodes, asking whether worm castings can be sterilised in the oven. Catarina says, "I sterilise my ingredients in the oven for half-an-hour at 100C. I can't find good ingredients which I can afford as a student. In this heat, no insects, pests or bacteria can survive?" It's a really good thought and there's absolutely nothing wrong with doing that. I guess, my point of view, the only downside is you are killing off anything in the way of beneficial bacteria as well as anything pest-wise, but I do appreciate your dilemma. If you have got those supplies then why not use them?

Last dip into the email inbox to mention a message from Sarah who got in touch after listening to the silicon episode. Sarah's a horticulture professional and uses a silicon supplement called Pro-tect with great success: "My company mainly does interior plants," Sarah writes, "And we've added it regularly to our fertiliser schedule for years, but the past couple of years I've used it in our exterior mix planters and it has made a real difference. The plants withstand drought better and the foliage is noticeably more shiny and healthier. In some cases it changes how the leaves actually feel. It's hard to describe but they're sturdier and more beautiful." How interesting! Well, I guess that's just because they've got more silicon in them.

Thanks to new Patreons Liz, Hannah and Suzanna this week. Suzanna let me know that On The Ledge saved their String of Pearls. Well, that's great news and that's what this show is all about, saving your houseplants one care tip at a time. Just a reminder to all Patreons that you need to make sure your address is up-to-date on your Patreon profile so that I can send out your festive, December mail out. So, if you're a subscriber of $5/month or more, make sure that address is right. I'll be dropping a message to everybody who hasn't registered their address in the next couple of weeks, just in case you do want to change your mind on that. That way you'll get access to the mail-out, which is in progress as I speak and very exciting. For the $5 tier, the Ledge-Ends, there's going to be a card a bit like last year, the $10 tier, well, it's going to be something super exciting. It's going to be a poster, one that you can put up among your houseplants and is going to look gorgeous. It's been designed by a listener who just happens to be a graphic designer, so I'm very excited to share that with you. That poster, that design, will also become available on my SpreadShirt shop for merchandise.

You may remember recently that I put out a call for Meet the Listener candidates from Scandinavia. Well, I'm very glad to say Mia volunteered herself for the job and here she is answering those five vital questions.

[music]

Mia: My name is Mia, a 41-year-old plant lover living in Stockholm, Sweden. I have always had a great interest in both indoor and outdoor gardening. During summer I focused on turning my piece of old forest land into a garden, which is quite exhausting. Now that we're approaching the colder season, I can focus on my houseplants instead. I think that the much more limited space makes it less stressful and much more enjoyable to me. A couple of years ago I discovered On The Ledge and I'm so happy that I can develop my houseplant skills while trail-running at the same time. That, in combination, has meant a lot to me, especially during the pandemic.

Jane: Question one. You've been selected to travel to Mars as part of the first human colony on the Red Planet. There's only room for one houseplant from your collection on board. Which plant do you choose?

Mia: First of all, I would never go to Mars! I'd rather die, to be honest. Ignoring that, the plant I would bring on this awful journey would have to be big my Peace Lily, Spathiphyllum wallisii, not that it's a rare or especially beautiful plant in any way but because NASA concluded that it's excellent for cleaning the air in a space station, which could be useful. I guess the question is all about which one of my houseplants I care most about and wouldn't want to lose? So, I'd say one of my old, big Hoya carnosas. I've had mine for nearly 20 years. Like many others, I got it from a grandmother, just not my grandmother. She, in turn, got it from her mother and they have both gone, since long, but the plants still remind me of the old lady who I liked a lot and it was also my first Hoya that sparked my interest in the rest of the Hoya genus.

Jane: Question two. What is your favourite episode of On The Ledge?

Mia: My favourite episode of On The Ledge would have to be one of the Hoya episodes and that is 82 and 123, since I love Hoyas. I've actually listened to the same episodes several times. Since I almost freak out every time a small piece of perlite has landed on one of my darlings, dreading that it's a mealybug, I also appreciated episode 143 on the topic of mealybugs. I almost lost all of my orchids in 2019 to mealybugs and it was terrible.

Jane: Question three. Which Latin name do you say to impress people?

Mia: My friends are quite easily impressed by any Latin name I drop, since none of them really share my interest. I do like to say Hoya **subquintuplinervis just because it's so hard to get it right. I believe it's the same as Hoya pachyclada, sothat could be used instead.

Jane: Question four. Crassulacean acid metabolism or guttation?

Mia: I long heard that question without understanding it until it was explained in an episode some months back. I guess I must say CAM because it's simply genius. Nature is so clever and fascinating.

Jane: Question five. Would you rather spend £200 on a variegated Monstera, or £200 on 20 interesting cacti?

Mia: I have never been a big fan of Monsteras, nor variegation, and £200 is a lot of money to spend on one plant. However, if I would see it as an investment, I guess I could easily get the money back since they're sold for much more these days. Since I don't make any money on my houseplants, I would have to go with the 20 cacti. I guess I would appreciate the variation more and cacti can be rather interesting plants even though I must say they come nowhere near Hoyas -- obviously!

[music]

Jane: Thank you, Mia. I'm glad to hear that I'm not the only one who's had a panic attack every time I see a bit of stray perlite on a succulent because that was me this week, checking out my Kalanchoes in my greenhouse. Yes, the fear is real! If you'd like to put yourself forward for Meet the Listener, then drop a line to ontheledgepodcast@gmail.com and my assistant, Kelly, will fill you in on how to take part!

It's time for another instalment in my occasional leaf botany series and I'm joined this week by Nox Makunga, who is a plant scientist working in the department of botany and zoology at Stellenbosch University in South Africa, shining a light on the people of colour who are working in the field of botany around the world. I'll put a link in the show notes to find out more about Black Botanist Week - do check it out. Now, on with the interview!

Jane: Thanks for joining me Professor Nox Makunga and we have got some very interesting things to talk about today. I have been looking at my houseplant leaves for many a year and wondering why on earth they are the amazing colours they are. I'm hoping you're going to be able to provide some of the answers to some of those questions today, in this leaf botany special. I guess the first thing to ask, and this is really something that I thought I knew but then when I thought more deeply I realised I have no idea exactly what they are! What are the pigments that turn our plants different colours?

Nox: There are definitely leaves, well, plant pigments that are in our leaves, and quite a variety, that give beautiful colours. Examples being anthocyanins, which give the red colours that you see during autumn when the chlorophyll degrades, and also flavonoids, which give beautiful yellow and orange colours and these all come from quite a complex type of metabolism which is very specialised, but these colours or pigments are actually in the plant all the time, it's just that when the chlorophyll starts to break down, as temperatures drop and the day length changes during autumn, they become more prevalent and so we need to see them and enjoy them.

Jane: So we've got all these different wonderful pigments contributing to the beauty of our leaves but what are they actually doing to help the plant and to offer different functions?

Nox: They have quite a few functions, actually. The bright red colours, and even the yellows and the oranges, are mainly attractors for pollinators and to assist seed dispersal, when they're sitting in the fruit, but they also serve as protectants, so they perform the function of UV protection and similarly to us, that have pigment in order to deal with the harsh effects of ultraviolet light, plants will use these as protectors. Some plants use, particularly the carotenoids, as additional pigments or accessory pigments to assist with photosynthesis. So there are a variety of different functions and it makes it quite interesting to have plants that have these wonderful colours. Often plants will also express pigments when they're under stress, so when conditions are pretty stressful, these pigments are there as a means to deal with reactive oxygen species.

Jane: There are so many different, wonderful combinations of colours that we get in plants. One thing that I'm often asked is about changes of colour in plants. For example, somebody will report that their cactus or succulent, they moved its location and it's suddenly taken on a red tinge. Is that some kind of retrospective action by the plant to protect itself? Is it a stress response, when you get those red tinges?

Nox: Yes, it actually is and I'm really glad you've mentioned succulents and cacti because they often produce a different set of coloured pigments and these are known as betalains and beetroot has that very deep, red, purple/red colour and this would be betalains that it's actually producing. With the betalains, again, some of them are yellow, some of them are slightly orange and then, obviously, red. It's quite fascinating that a group of plants which belong to the order of Caryophyllales - that's quite a hard one to pronounce, that name - they have evolved the betalain metabolism and some of them also might generate anthocyanins and it's often dependent on which parts of the planet that they're actually found. The reds are really there for protection and to protect the plant from ultraviolet light and it is also related to stress. So when plants are stressed they start to generate the facialised compounds that actually do facilitate their ability to cope with a particular stress. For example, I did a really lovely experiment where I took a plant that I work on, which is actually a succulent, and we placed it on a growth medium, which had high levels of salt and within a few days those beautiful reds started to actually express themselves. So, often those colours, especially the bright colours that are red, orange and yellow, are linked to stress-regulated metabolism.

Jane: That's really interesting and it gives you an insight into our human desire to make our plants do dramatic things. I always think of the very popular houseplant, String of Hearts, which I've seen being sold and they're claiming it's some kind of pink cultivar, whereas looking at it, it's quite clear to me that it's just the plant has been stressed. It's being sold under false pretences, really, as being some kind of pink cultivar, whereas actually, the plant's just stressed and lots of people have reported that when they get it home and after it's been there for a few weeks it's gone green because it's no longer stressed in whatever way they were stressing it. It's interesting how we can manipulate plants in this way to do different things to give them a different appearance. It's certainly something that seems to be exploited to some extent, particularly by cactus and succulent growers in various ways. One of the other things that I've noticed, and certainly a lot of my listeners have noticed, certainly with lots of subtropical plants and tropical plants, is lots of leaves with red undersides. This could be Begonias, this could be lots of members of the Maranta group and I haven't been able to find out one, definitive answer as to why that is a useful thing to do, perhaps because there isn't one overarching reason, but what are the different reasons for a plant to have a lot of red pigment on the undersides?

Nox: Well, I think sometimes they grade their pigment, so the top part might be very green and that will have lots of chlorophylls and those chlorophylls are absorbing the light because it is a top surface of a plant that is generally absorbing lots of light. The green pigment will be sitting at the top and the under-surface will have a different colour because that's not necessarily part of the leaf that's absorbing a lot of light. I think it often depends on their evolutionary trait and environments that they might be growing in. There's lots of different mechanisms that might be responsible for plants to actually have different pigments in different places and even at different times. It is quite complex and I don't think we have all of the answers with regards to this. I would say often it is shade-loving plants that might actually have red pigment and again I would say that's an evolutionary trait to facilitate coping with environments that might result in lots of sun exposure.

Jane: As humans we love to look at these leaves, and the reasons why we love these leaves might be completely different from the reasons why the plants themselves have come up with these different strategies, but it does make them very attractive to us when you get these amazing colours. One of the things that I've noticed on the variegated - often when you've got variegated plants that have got a lot of white where there's just no chlorophyll present - these leaves seem to suffer quite badly from burning. So is that because there's a lack of pigment - this is a very amateur description - but acting as sun protection for the plant and when that's missing, the leaf burns? Or is there some other reason why you get burns on plants with very little pigment in them?

Nox: That's absolutely right. I think those parts that are white generally lack pigment and as a result they're more susceptible to sunburn. A lot of these pigments are often acting as sunscreens and so in areas where there's a deficiency, indeed, they're much more susceptible to burn. The areas that have got pigment are light-absorbing and they are able to actually handle the effects of UV light. So the suite of photosynthetic machinery actually also is somehow acting as a protectant because it is protecting DNA and very sensitive photosynthetic complexes that are involved in photosynthesis. So places that are white are more likely to burn.

[music]

Jane: We'll be hearing more from Nox shortly but now it's Question of the Week and it comes from Kathleen, who wants some guidance for her propagation project, a Silver Ripple Peperomia. It's been in water, in a zip-lock bag, and has sprouted tiny translucent roots but Kathleen's not sure what to do next. Well, we've all been there! You have a mad spree of propagation and then what do you do? When do you transfer those plants to soil? When are they ready and when is that propagation sweet spot? If you're not familiar with this particular cultivar of Peperomia, it's actually a cultivar of the species Peperomia caperata**,with the wonderfully ruffled, or even corrugated, leaves, heart-shaped, very beautiful, and in the case of this cultivar, it's got this beautiful silver sheen, which is lighter, between the veins and the dark vein system running through the leaf. Really beautiful. So, well done for having this beautiful plant, Kathleen. I'm not quite sure how you propagated your plant, Kathleen, but it sounds like you've been using a clear plastic bag, perhaps the cutting has just been sat in there in a little bit of water?

If you've listened to the episode I did with Sally Williams, the national collection holder of Peperomia here in the UK, then you'll know that her hummus pot method is a brilliant way of propagating these plants. So Kathleen's plant has got tiny translucent roots. I guess the key question is how long are those roots? If the roots are merely a couple of millimetres or even centimetres long, anything less than a couple of centimetres, or an inch in old money if you prefer, then I would say keep it in the water and wait a bit longer. Ideally I would say the roots need to be somewhere between two and five centimetres for the plant to be ready to pot up. Why does that make a difference? Well, if you only have tiny roots then once the plant has gone into its potting mix, as opposed to being in water, the surface area of the root will dictate how much water can be absorbed. Tiny roots can't do as much work as larger roots, so it's really worth waiting for those roots to develop a bit more and then your plant will have a better chance of being established. It's worth saying that sometimes Peperomias can be quite slow to propagate this way. I had a lovely Peperomja maculosa - I think I've mentioned it on the show before - this is, in my opinion, one of the most interesting Peperomias there is. It's got these large, large leaves, which can be up to 20cm long and they have a nice smell as well - a spicy-ish smell - and it's actually a medicinal plant in its home country of Guatemala. Unfortunately, I overwatered my plant and I was left with not even just one leaf but a section of a leaf which I managed to save and propagate. The plant's going but it's just being extremely slow to establish any top growth and that's because it's putting all its energy into making more roots. So, for Kathleen, I would say hang in there with your propagation and let those roots get a bit longer.

What do you do then once the roots have reached the required length? Then it's question of transitioning your plant into life in a potting mix as opposed to just being in water. Once it's out of that plastic bag, air humidity is obviously going to drop, so it's very wise once you've potted up your cutting to actually put a plastic bag around the whole thing, pot and all, that way you're creating a little microclimate that these plants will actually love. Higher air humidity means the plant will have to transpire less which means the roots will have to do less work, so it's a really good way of giving plants a slightly less stressful environment to really get established. Then, once you're convinced the plant is happy and settled in, you can start taking that bag off for a little period every day, until the plant is ready to go it on its own - you can take the bag off completely. I'm propagating some Peperomia incana cuttings at the moment, just in water, another one of my absolute favourite Peperomias**, and it's fine to do this propagation at any time of year, it just means that if you are in your winter time and light is lower, then you may find the plant is slower to establish itself and you can offer some extra light or some extra heat, or both, by putting the plant on a heat mat, putting it under a growlight and so on. It depends on how much you want to cosset your plant, really.

The other thing worth saying with these cuttings is, if you're propagating from a single leaf, at what point will that single leaf, that was the originator of the cutting, start to die off? Well, it depends. It may start getting in the way of the new plant developing but you've got to judge it yourself as to when the plant has enough new leaves to be able to photosynthesise effectively. You may find the leaf just dies off of its own accord, or you might need to cut some of it away. It's really a question of using your judgement and not letting that leaf rot because then you might encourage botrytis to set in - you don't want any fungal conditions. So, if anything starts to rot then do nip it off with a clean pair of scissors straight away making sure that you cut beyond the healthy material to make sure that the rot can't progress any further. Just so you don't think that I am some kind of Peperomia genius, I have to say I'm really struggling with my Watermelon Peperomia at the moment. It got stuck behind another plant, and hidden, and thus neglected for a long time and, boy, is it looking fed up. So, send kind thoughts for my Watermelon Peperomia, Peperomia argyreia, because I really need to start taking care of that plant. It's very beautiful and unfortunately it's got neglected for quite a few weeks, so my bad. This is what happens, as I say so many times, if you leave plants in places where they're not being spotted: you won't spot the problems when they start.

Do go back and listen to those two Peperomia episodes if you want to know more about Peperomias. They're a really fascinating group of plants. I do warn you, if you end up getting started on mass propagation of Peperomias**, it is rather addictive, so watch out! You may have to find some friends in need of some new plants before long! And if you've got a question for On The Ledge, drop me a line: ontheledgepodcast@gmail.com

[music]

Jane: Right, now it's time to head back to my chat with Professor Nox Makunga.

Jane: Working in Cape Town in South Africa, I imagine there's so many plants that we grow as houseplants that originate from your part of the world, so it must be an amazing place to be a botanist? Can you tell me about some of the plants that you're researching right now? What things are you working on?

Nox: I work on a variety of different things. Most of them are of medicinal value. We've been doing a project on Rooibos, Aspalathus linearis, and those plants are quite unique in that they come from very restricted areas in South Africa, in Cederberg mountains and certain parts of the Northern Cape. So they are uniquely developed to be able to handle the climates around those areas. I had a conversation with someone the other day and they thought that Rooibos is everywhere in South Africa just because Rooibos is now found all over the world as a tea, and in actual fact it comes from a very unique set of environments. So I prefer to work on medicinal plants of South Africa, and especially those that come from Cape Flora, and the reason for this is because this Cape Floristic Region is really fascinating for a botanist. It's a small area, it's a non-tropical part of the world, it's got a Mediterranean climate, the ecology of this region is really quite spectacular and, for a plant scientist, creates lots of interesting ecological, physiological questions and even questions linked to the molecular biology of these plants that have radiated and dispersed in this part of South Africa. And many of the plants that are found here are actually very strict endemics, but horticulturally they're found all over the world. I would say Pelargoniums, for example, have become loved in all types of areas and you often see them on windowsills in Europe. They belong to the family Geraniaceae and people love those plants but they actually have an African origin.

So, other plants I work on happen to be succulents. So I started a project looking at a species known as Sceletium tortuosum and in South Africa it's been utilised for centuries to create happiness. It has a set of mesembrine alkaloids that are antidepressants and Sceletium is sometimes taken as part of a tea and it has these compounds that actually are mood-alleviating and make you feel happy. So that's one species I've been working on and it's one of these plants that also starts to turn red once it's actually stressed. Something else that's quite fascinating about it is that in a field it likes to hide underneath a little shrub. Again, I think it's that idea of hiding away from sunlight that might be causing deleterious effects on its growth form. When it is exposed to sunlight it pops out these betalain pigments that happen to be red. I work on this because it's been commercialised as being an antidepressant and it's got a really long history of use amongst the Khoi and San People of South Africa. So those are just two examples of plants that I work on. Do you want to know about more?

Jane: I'm fascinated by this! First of all, I guess I knew somewhere deep in my consciousness that Pelargoniums were from The Cape, but really, that's blown me away because that is a plant that has spread all over the world! I'm sure that if you ask most people they would have absolutely no idea! They might think it came from the Mediterranean because so often they're associated with a beautiful white washed Mediterranean house with a balcony of Pelargoniums, but it's so interesting to remember that they're actually from your part of the world and what a fantastic plant! Tell me about one more plant that you're studying if you would?

Nox: I also work with a plant called Sutherlandia frutescens and this is legume, it's a medicinal legume. In Afrikaans, it's called Kankerbos, which means cancer bush. It has a history of being used as a treatment for cancer and we've been working on this species for quite a long while now and we're interested in it because, again, it has been commercialised in South Africa. It is known to have anti-diabetic effects. It has immunomodulatary effects and it also has a stress-relieving effect. You have various different products that are made here, so, again, you find it as tinctures that you can take as little drops, you also have it being incorporated into cosmetics and a variety of other products, teas, gels, all kinds of different products. That particular species actually has a much broader distribution here in South Africa and where it is found, it's basically used. So, in areas like KwaZulu Natal at some stage they were using it as an anti-HIV treatment and in The Cape it is used mainly for cancer treatment by local people and sometimes it's just included in plant herbal mixtures, just to boost and lift their immune system. So it's a species I've been working on for quite a while and some of the work that we've done is to try and look at different chemo types that you find in these variable geographic areas and what's really interesting is that plants from different regions have different pharmacological activity and this is probably a genetic variation rather than an environmental, controlled process. So those are the kinds of questions that I'm interested in my laboratory and we also have created a system where we grow these plants in tissue culture and we torture them a little bit by changing the environmental conditions, to see how they're going to respond. We may change nitrogen and phosphate and we monitor to see how they express their medicinal properties. We think that this information is really useful for the commercialisation of a species but also by applying tissue culture and growing these plants en masse and thus actually saving populations that are found in limited numbers in the wild.

Jane: Well, that is really fascinating, isn't it? It's amazing what plants can do and this is why we need botanists like you, Nox, to bring us this fascinating insight into the plants around us! Nox Makunga, thank you so much for joining me today. I've learned loads and it's been a real pleasure to chat to you!

Nox: Thank you so much for this wonderful conversation. It's a wonderful day in the Cape. I'm looking at the mountains at the moment while I'm doing this, so I'm hoping that you are having a good afternoon and I love to talk about plants and love to talk about South African plants and it's been a wonderful conversation and I really appreciate the invite!

[music]

Jane: Do check out Black Botanist Week it's a wonderful way of discovering people of colour working in the field of botany and I'll include all the relevant links in the show notes. That's all for this week's episode, I will be back next Friday with episode 161 and the following week I'll be taking a break for my children's half-term holiday, so, no episode on October 30th. Thanks for joining me this week! Whatever you get up to, remember to stay hydrated, feel the sun on your face and make sure you get plenty of fresh air. Bye!

[music]

Jane: The music you heard in this episode was Roll Jordan Roll by The Joy Drops, An Instrument the Boy Called Happy Day, Gokarna by Samuel Corwin and The Encouragement Stick by Doctor Turtle. All tracks are licensed under Creative Commons. Visit janeperrone.com for details.

Subscribe to On The Ledge via Spotify, Apple Podcasts, Player FM, Stitcher, Overcast, RadioPublic and YouTube.

Professor Nox Makunga of Stellenbosch University in South Africa joins me to explain the pigments that give houseplant leaves their colours, I answer a question about a ‘Silver Ripple’ Peperomia and we hear from listener Mia.

This week’s guest

Professor Nox Makunga works in the Department of Botany and Zoology at Stellenbosch University in South Africa. She’s on Twitter as @noxthelion and on Instagram as @nox_makunga.

Want to find out more about Black Botanists Week? They’re on Twitter as @BlkBotanistsWk and their website is here.

Check out the links below as you listen…

The main pigments found in leaves are chlorophylls (greens), carotenoids (yellows and oranges) and anthocyanins (reds).
Betalains are red/yellow pigments found in plants of the order Caryophyllales, which includes cacti and beets.
Prof Makunga mentions various research plants she is researching: specifically rooibos aka Aspalathus linearis; kanna aka Sceletium tortuosum; and the legume Sutherlandia frutescens aka cancer bush.

Peperomia caperata ‘Silver Ripple’. Photograph: Steve’s Leaves — *Peperomia caperata* ‘Silver Ripple’. Photograph: Steve’s Leaves

Question of the week

How does Kathleen know when her Peperomia caperata ‘Silver Ripple’ cutting is ready to be planted up? Roots should be around 2-5cm long before they are ready to go into soil: that way they will be big enough to help the plant access the water and nutrients it needs. Give your cutting a helping hand by wrapping a clear plastic bag around the cutting and pot once you have put it into your soil. The other Peperomias I mention in this episode are P. maculosa and P. incana.

Do listen to my Peperomia episodes (parts one and two) for more on Peperomias and their propagation including Sally Williams’ hummus pot method.

Want to ask me a question? Email ontheledgepodcast@gmail.com. The more information you can include, the better - pictures of your plant, details of your location and how long you have had the plant are always useful to help solve your issue!

HOW TO SUPPORT ON THE LEDGE

Contributions from On The Ledge listeners help to pay for all the things that have made the show possible over the last few years: equipment, travel expenses, editing, admin support and transcription.

Want to make a one-off donation? You can do that through my ko-fi.com page, or via Paypal.

Want to make a regular donation? Join the On The Ledge community on Patreon! Whether you can only spare a dollar or a pound, or want to make a bigger commitment, there’s something for you: see all the tiers and sign up for Patreon here.

The Crazy Plant Person tier just gives you a warm fuzzy feeling of supporting the show you love.
The Ledge End tier gives you access to two extra episodes a month, known as An Extra Leaf, as well as ad-free versions of the main podcast on weeks where there’s a paid advertising spot, and access to occasional patron-only Zoom sessions.
My Superfan tier earns you a personal greeting from me in the mail including a limited edition postcard, as well as ad-free episodes.

If you like the idea of supporting On The Ledge on a regular basis but don't know what Patreon's all about, check out the FAQ here: if you still have questions, leave a comment or email me - ontheledgepodcast@gmail.com. If you're already supporting others via Patreon, just click here to set up your rewards!

If you prefer to support the show in other ways, please do go and rate and review On The Ledge on Apple Podcasts, Stitcher or wherever you listen. It's lovely to read your kind comments, and it really helps new listeners to find the show. You can also tweet or post about the show on social media - use #OnTheLedgePodcast so I’ll pick up on it!