Episode 188: getting started with terrariums
An InSitu Ecosystems terrarium.
Transcript
Episode 188
[music]
Jane: If you want to hone some new skills this Spring, check out Learning With Experts, the global classroom community that brings people together to learn from the best in the business. Their range of courses covers everything from food and drink, to photography and gardening, so why not become an accredited garden designer and learn with world-renowned experts including influential Dutch garden designer Piet Oudolf and multi-award-winning British designer Tom Stuart-Smith or take a course on herb gardening, natural beekeeping or growing veg? You can start whenever it suits and you get to meet other gardening enthusiasts in the sociable online classroom. Visit learningwithexperts.com/ontheledge now for 10% off your first course. That's learningwithexperts.com/ontheledge. Learning With Experts: online learning that's guaranteed to lift the spirits!
[music]
Jane: Come with me to a steamy place full of plants, yes, we're talking terrariums this week in On The Ledge. I am your hard-working host, Jane Perrone, and this is the show that brings you the houseplant info you need. This week, Jacob James from Grow Tropicals joins me to talk about starting terrariums, the best plants, lighting, substrates and more. And I answer a question about toxic Aroids. I don't mean the high prices for rare plants, although that is quite toxic, I mean the chemicals inside your favourite Aroids that might make you or your pets poorly, if you decide to eat them.
[music]
Jane: The big plant news around here this week is that my daughter has finally started to show an interest in plants! Result! She's a teenager and she's just started asking me if she can have plants for her room. So far, she's got a succulent and a cactus and she's asking for more. She has given them names, which she says is helping her remember to water them, so, yes, my influence is beginning to have an effect. Mwah ha ha! Sorry - got a bit over the top there!
Anyway, we're talking about terrariums today. I can't help when I think of #talkingterrariums of that Bananarama song, which was actually called Talking Italian, but many of you may be too young to remember that. Thanks for all your love regarding the Snake Plant episode. And Dr Colin Walker - what a star - has packaged up some of the Sansevieria species he was talking about that are not in my collection and is sending me a load of plants. Colin, you are a hero! Thank you so much for that. I've also been doing some propagating and getting ready to give away more plants because that is what gives me a big kick. I love to give away plants! I recently did a swap with somebody and they were worried that the plant that they were sending me as a cutting was not as valuable as the plant that I was giving them and I said, "Well it's a bit of an arbitrary figure, really, what the market rate for my Hoya cutting is, versus the rate for your C**eropegia cutting! It's all immaterial for me because I've got something you want and you've got something I want, so that's all that matters!" That's my philosophy and I'm going to stick by it.
Alright, enough preaching to the converted! It's time for today's interview, with Jacob James covering all things under glass.
Jacob: I'm Jacob James. I'm one of the founders of Grow Tropicals. We're a specialist nursery that specialises in rare tropical houseplants and also plants for the terrarium hobby as well.
Jane: I'm very glad to have you here talking about terrariums, Jacob, because it's one of those issues that I tackled right back at the beginning of the show I haven't really come back to in any depth, so this should be a real treat. Jacob, could you just start off by telling me whether you were like me and this was something that started as a child, a passion for terrariums, or is it something that's developed later in life?
Jacob: I think I actually came into terrariums maybe slightly differently even than the other guys that I work with here. The reason I got into terrarium and terrarium plants, it came about as I was collecting bigger, rare tropical plants, Aroids and these things, and I hit a limit of how many plants I could fit in my house. So then I started to look for smaller and smaller species. I started to look at miniature Philodendrons**, M**arcgravia, this kind of thing and that actually led me down a rabbit hole to meeting a whole new community of people who mostly came in from the reptile hobby or the dart frog collecting hobby and it met in the middle with this real fascination for particularly miniature, rare and most often neo-tropical terrarium plants.
Jane: I get rather upset, Jacob, by looking online at some of the terrarium pictures and advice out there because a lot of it is really quite poor. So I'm just wondering if you can start off by giving us an overall outline for anyone starting out with terrariums about what you need and how to get started?
Jacob: I think the obvious bad advice, and the one that you see a lot, is people putting things like cacti and succulents into terrariums and that's probably the opposite to the ideal environment for those plants. So the ideal plants really for terraria are your small species that are found in the understory of a rainforest or the small climbing, shingling plants that you'll find at the base of large trees in the rainforest. Those are the ones that we're interested in and cultivating for terrariums because they're often tolerant of low light, they need a high humidity coming from the tropics they often require reasonable temperature and what you find, inside a terrarium, the temperature tends to be, at least as a minimum, a couple of degrees above the ambient temperature in your house. So even if you're not heating them and putting too much light on them, what you'll find is the temperature tends to hang around, say, 20C and then as soon as you start putting lights and things, that can go higher, so you really want plants that are tolerant of warm temperatures, tolerant of high humidity and also don't need lots and lots of light. I think, what we often forget when growing plants in general indoors, is that what feels like a lot of light through a grow light or an aquarium light or whatever you're choosing to light the terrarium with, it's actually very minuscule compared to bright, outdoor full sun, so yes, it's really these understory plants. I think the key components to actually growing in a terrarium is, you want a really nice, fast-draining substrate. So a lot of people originally, probably in the last ten years, particularly coming through innovations in the reptile and dart frog hobbies, developed substrates such as one that's called ABG, which is a mixture of peat, bark, tree fern fibre, all of these things. I think what a lot of people have realised, probably over the last five years, is that often the conditions you find on the understory of the rainforest is actually the soil and the substrates that plants are growing in is incredibly nutrient-poor, actually, because what happens is it's always wet, it's raining a lot, and that causes the nutrients to leach out the soil really fast. So there's been a move more towards inorganic substrates in the last few years, so a lot of people are using things like clay, akadama, pumice, lava rock, all these things that really just help to give the roots structure but also hold in a little bit of nutrient, but also allow the water to drain out really fast. In a sealed terrarium environment, a lot of people will have a basic drainage layer at the bottom and this just gives the excess moisture somewhere to run off to so it's not always sitting in the substrate because, even though a lot of these plants are used to growing in very wet environments, they don't want to be boggy around the roots because that just leads to root rot. It's really about having fast-draining substrate, high humidity, lots of warmth and a reasonable amount of light, but you don't need tons and tons of light.
Jane: Just going back to the cacti and succulents in glass boxes thing - I know I'm a bit obsessed with this topic but is there a reason why this is so popular, even though it's really not a great practice? Is it because cacti are just more available than the plants that actually work in a terrarium, or is there something else going on?
Jacob: No I can't either. I think it's probably a little bit of everything. I think one of the benefits of things like succulents and cacti is they're quite slow growing and I guess this is one point that I didn't touch on in the last answer, was we also often look for plants that don't grow too fast. Because I think what you find is, if you put a fast-growing plant in, within two/three/four months it's going to fill your terrarium. A lot of people go to terrariums because they're relatively minimal maintenance and care and the last thing you want to be doing is chopping away plants every week just to keep it free. So I think some of it's to do with slow growing and I think the other is probably somebody, who was not very knowledgeable at some point, made one with a cactus or a succulent posted on something like Pinterest and this received wisdom just gets passed down, whether it's correct or not. Then you've got retailers. Recently, I think Primark did one with cacti in, or a succulent in it, so I think probably the cost is an element as well. Slow-growing miniature plants are still hard to source, they're still quite expensive, relatively speaking, so yes, I imagine it's a little bit of all of those elements coming together.
Jane: I'm showing my age here, but when I was a kid I used to make terrariums out of those big sweet jars. You'd go to the corner shop and buy a quarter of cola cubes and if you asked nicely you might be able to take a jar or two home. They were great because they had really wide necks, obviously times have moved on, and there are many other things to make terrariums out of. What are the characteristics of a good vessel to use as a terrarium?
Jacob: I think there's two ways of approaching terrariums. There's the larger set-up, where people are using the same terrariums as you would keep reptiles or dart frogs in and these enclosures really allow you to create something a little bit bigger, a little bit more complex. You can hook them up to misting systems and light systems and all this but, equally, there's also the school of terrariums where it's, as you say, it's building them in small vases, in fish bowls, in bottles. I think there's some really easy ways to get started with terrariums that doesn't require huge investments in your vessel. I've personally made them in small vases. If you go to places like Homesense and these kind of shops that they do a little bit of everything for homeware, you can often find nice fish bowls, style vases, you can find square vases and then, very cheaply, you can get small pieces of acrylic cut to size to sit on top as a lid and that can be a really low-cost way of getting into terraria. I think more and more, we're now seeing also garden centres and traditional garden retailers getting into the terrarium idea as well. So I know a lot of garden centres I've been to recently have had terrarium areas, with vessels and whatnot, and I think as the hobby grows and interest in it grows, I think we'll start to see that: vessels and terraria available in lots of places.
Jane: Some listeners might not be familiar with that substance akadama. Can you just tell us a little bit more about that and what it's used for?
Jacob: My understanding is it's basically a clay-based substrate. Originally, it was developed in Japan for the Bonsai industry, actually. So my understanding is the difference between akadama and some of the other clay substrates is, actually, akadama is mined and depending on how deep they take it from the ground it gives different grades. So the more expensive stuff is harder, so it doesn't break down as fast and then you can get the cheaper one, which is slightly softer. The good thing with clay-based substrates is they have, it sounds a bit science-y, they have what's called a high cation exchange capacity, which basically, in layman's terms, means that it can hold a lot of nutrients and slowly release them. So the more you use it, the more it can basically become charged with nutrient without burning the roots or anything. So even though it's an inorganic substrate, over time each one becomes little sponges. They also hold quite a lot of moisture but also are fast-draining, so it has a nice oxygen to soil substrate ratio, so you get a lot of oxygen, a lot of air to the roots, while still staying moist and what that does is that also helps to prevent rot when it's constantly damp. A lot of people use akadama a lot for sensitive Begonia, small, really expensive terrarium Begonias. I personally have an interest in a group of plants that are known as Rheophytes, so they're plants that grow along the banks of rivers, in the rainforest and in the monsoon season, often grow submerged underwater, then, in the dry season, grow immersed. So by 'immersed', it means the roots are under water, or are very wet, but the foliage is above water. So I often use a mixture of akadama, charcoal, maybe a bit of pumice, because it allows it to stay wet but without causing rot problems. For that reason, it makes a perfect substrate for terraria as well because it allows it to be wet regularly but without breaking down, without creating anaerobic conditions which rot the roots of the plants.
Jane: If you're just starting out and you maybe don't have access to loads of different substrates, is it mainly just a case of having a drainage layer and a potting mix, maybe divided by some kind of mesh, is that the basic stuff that you need?
Jacob: Yes. To be honest, the beauty of a terrarium, should I say, is that the high humidity and warmth is ideal for growing conditions for most plants. So even the rarer plants will thrive in the same way that your cheaper, more accessible plants will. In terms of substrates, probably the cheapest and easiest way to get started is to use something like grit, or if you can, buy small Leca, the small clay granules that you can get from most garden centres, as your drainage layer. Then either something like weed stop fabric or the material that they use for sun blinds on cars, basically, a really fine mesh and what that will do, is that will help keep your substrate layer out of your drainage layer. Then the substrate layer can be anything that doesn't stay too wet for too long. So I tend to stay away from your traditional houseplant compost because it tends to hold, probably, a little bit too much moisture, but what you can do is you can create a mix very easily with bark, with a bit of perlite to help drainage, if you can find it, pumice, some garden centres have it, some don't. A little bit of sphagnum moss on the top of the substrate layer can help to keep a bit of moisture in and humidity up, but as long as it's staying moist but not too boggy, the actual substrate can be pretty much anything that's fast draining. A lot of the time in garden centres, you can find Bonsai soils or you can find soils that are designed for cacti or for orchids. These all tend to be fast-draining and any of those will be pretty good. If it's a simple bottle style terrarium you can control how moist that is simply by how much you spray water into it. So the trick, really, is to keep the humidity in the vessel high and the substrate not soaking wet. So even just spraying the glass every now and then can keep the humidity up without saturating the substrate layer.
[music]
Jane: If someone's got, say, a small fish tank and they want to start off planting it up without resorting to any very rare and hard to get plants, what kind of things are we talking about? Small ferns? Mosses? Where do we start?
Jacob: In terms of affordable plants to get started with, one of the best places to look is stores that sell aquarium plants. A lot of aquarium plants are, as I said before, Rheophytes. What that means is they don't naturally always grow under water but when they grow immersed above water, they need high humidity. So they're really good for terrariums, so things like bucephalandra, cryptocoryne, all of these plants are slow growing, really amazing foliage and you can pick them up £5/£6 each and they're pretty much perfect for these vessels. I think where a lot of people often go wrong with terrariums, is they see small versions of big plants at garden centres, or in houseplant shops, and think it's a small plant and suddenly it's growing at the top, you really need the species that stay smaller. There's also some plants which you can get hold of relatively easy now, species like M**arcgravia, which are shingling, climbing plants, and Marcgravia sintenisii and umbellata. Those two are relatively affordable, relatively accessible, but you'd probably need to go to a terrarium specialist for those kind of plants. Then, also, plants like Bromeliads. There's quite a lot of cheap Bromeliads available now. Often stores designed for terraria, actually for reptile keeping and dart frog keeping, often stock the smaller species of Bromeliads because dart frogs actually spawn inside the Bromeliads, so they're used a lot in those terraria. Even things like air plants work really well in terraria, as long as you mount them to, say, a piece of wood, so they're not sat in the substrate, they thrive in that high humidity environment.
Jane: I do love those shingling vines. They just look so awesome. Is the key trying to mix it up in terms of different colours, shapes, forms and so on, when you're choosing plants?
Jacob: Yes, I think there's a couple of schools on how people tend to do this. My own, personal taste is I often find in-situ pictures of rainforest and try and recreate a slice of rainforest. So my taste tends to be quite naturalistic in how I want it, so I don't tend to use super-colourful plants. I maybe have one or two with lots of colour and the rest is green in texture. Some people like really colourful plants and will fill it with the brightest Bromeliads and fern species. So I think it really depends where you want to go with how you want it to look.
Jane: Yes, I do love those brightly coloured Bromeliads. They are just so cool. Another thing that some people spend an awful lot of time and money on is growlights, but are they an absolute essential or can you get away without using them? Does it depend on what set-up you've got and what plants you're using?
Jacob: I wouldn't say lighting is essential depending on your conditions. I think if you've got a spot that is close to a window where you're growing normal houseplants that doesn't get direct sunlight, that will be probably enough light to get started, but I think you'll really see an improvement from having a light on the terrarium. Now, it doesn't necessarily have to be a really expensive growlight or a super expensive aquarium light, or one specifically for terrariums, it can be anything from an IKEA bulb. They, at one point, and I think they still do them, they were actually doing growlights for around £10 that fit into normal light fixtures and I think that's a really good way of getting started. Then, over time, you can invest in better lighting and I think you will see better results with better lighting, but there does come a point of diminishing returns. So I know, for example in our shop, we tend to only stock the mid-range stuff because once you get above that, it's really quite specialised and lights can go for thousands of pounds.
Jane: Those IKEA lights are great. I've got a couple which are working absolutely fine. I don't think they're available in every IKEA around the world. I think, possibly, they're not available in North America, so sorry to disappoint you if any listeners are there. So let's assume we've set up a terrarium and now we need to keep our eyes peeled for things going wrong. What are the main things we need to be watching out for?
Jacob: The main thing that tends to go wrong with terrariums is either too much moisture, so particularly on sealed bottle style terrariums, if you start with too much moisture then there's nowhere for that moisture to go, so you will just end up with rot. I think with more complex terrariums, things that can go wrong is plants start to grow really fast and out-compete each other. So I think one of the things that will really benefit those terrariums is just regular pruning just regularly cutting everything back because what you'll find is that will help stimulate new growth but also keep control of the individual species and really help it settle in and grow as best as you can. I think, very occasionally, a little bit of fertiliser, if it's just a plant-only terrarium, will really help the plants to sing because in a closed environment, there's no nowhere for nutrients to enter into that system. I think the only thing you have to be wary of with nutrients in terrarium is that there's also nowhere for it to go, so you have to use it very sparingly because it builds up quite fast. So I tend to use the slower-release fertilisers, like your osmocote pellets and things like these, just a little bit into the substrate, just to give the plants something to feed on and grow from over time.
Jane: I know I've been guilty of not reading the application rate on the fertiliser packet. That is really important, particularly with a terrarium, presumably, where there's actually not that much soil inside it.
Jacob: Yes, it would not be a lot at all. I think with fertiliser, I always err on the side of less is more, initially, and then watch the plants, and if the plants start to fade in colour, or get a little yellow, then you know that maybe you need to add a little bit of fertiliser extra. I think it's very easy to add more fertilizer; it's very hard to take it away once you've added it.
Jane: So let's talk about some of the stars of the show. There are some gorgeous Begonias and some of those semi-aquatic plants that you were talking about that really are head turners. Can you talk us through some of those?
Jacob: For me the ones that really capture my interest are, like I said before, the Rheophytic species. So a lot of these come from Borneo. You tend to be able to get them from specialists like us, or from specialist aquarium stores. Then you also have plants which are relatively new to the hobby in the last couple of years, which are the miniature Philodendron species. So anyone who's familiar with your large Philodendron houseplants you can actually buy really miniature species with leaves that get no more than 3 cm/4 cm in size and I think these are really great for terraria because one of the difficulties with good terrarium design is scale. You want smaller species so that it looks like you've got a bigger slice of the rainforest than just the bottom of one big plant, so any plants that stay really small and compact. I think other plants which are gaining a lot of interest at the moment are, as you say, the rare terrarium Begonias. Again, most of them are from South East Asia. There's some really incredible ones of those. The only thing with the Begonias is that they tend to be a little bit more sensitive than some of the other terrarium plants, so, often you can have a beautifully grown plant and then the next day it's melted back to just the stem, so it takes a little bit more finesse to grow them really well. I touched on the Marcgravia species, there's some really common ones like sintenisii and umbellata, but then there's some incredibly rare ones as well. I think we cultivate about 40 species of Marcgravia, some with colourful leaves, some with almost neon margins on the leaves, some with serrated leaves, but all of them are climbers, some that grow really quite big and some that stay incredibly small, so I love Marcgravia, as a genus, for its diversity. Then the other plants that I personally really like are the miniature ferns. So, particularly in South America, there's some really great ferns that are in the M**icrogramma genus, with almost, like, snake skin texture, real crazy venation. Then there's also some in the Elaphoglossum family which have the most beautifully ornate fronds. They grow no more than maybe 4 cm/5 cm and they really are incredible. The only problem with the ferns is they tend to be slow growing and they tend to be hard to source. We've been trying to cultivate them for the last year or so and even in a year of growing we maybe end up with three or four plants from one plant, so they're nowhere near as prolific as some of the other species. So I think probably, over the next couple of years, they'll become more available and more readily available. I think the one other family of plants which I'm really interested in at the minute are the piper family, so the same family that we get black pepper from. There's a lot of really beautiful piper species that are actually undescribed in science at the minute. So they often go by names like species Indonesia, species Borneo, species Papua, but some that have really beautiful, almost black, foliage with pink venation and they look incredible offset against some of your more standard green foliage. I think it's really about mixing and matching and having a few star plants in a terrarium and a few more background texture plants as well.
Jane: I know that your company, Grow Tropicals, really majors on sustainability. Can you just talk a little bit about why you decided to put those sustainability goals at the heart of your business?
Jacob: When I started out the business, just over a year ago, there's a real rise in demand for these tropical plants and, as with anything that's slow growing like a lot of these plants, suddenly the demand outstripped the supply and that led to an increase in poaching, particularly in places like Indonesia and when you've got a crazy demand, reduced supply, the prices were going up and up and up and then, I would never blame the locals, but if they were out of work from the Covid pandemic and they could go into the jungle behind the house and cut out a plant and sell it to a westerner for a few hundred dollars, we would probably all do it in that situation. We made the commitment to, hopefully, work really to increase the supply of some of these rarer plants in the UK and I think, coupled with what was happening at the time with Brexit and, obviously the Covid pandemic was affecting logistics of getting plants into the country, it also made sense, from a business sense, to stabilise our supply of these plants as well. So it was as much a business decision, sustainability, but really, what we wanted to do was bring in some of these rare plants, cultivate them here and be able to offer them to customers in the UK. I think what we also realised was that plants that we were growing in our own conditions were much hardier, much stronger and, ultimately, better quality plants than the ones that were just imported and sold straight away. I think as that's evolved from the middle of last year, we've also started working with nurseries in Asia. So we recently started a project with nurseries in Indonesia, where we actually commit to buying plants in larger numbers and what that's allowed them to do, is to put in the infrastructure to propagate these plants and employ the local farmers - they call them farmers, often locals who were collecting plants from the rainforest - to actually bring them into employment, to use their skills to propagate and farm these plants which, before, were being poached. Also, the investment that's been made there has meant that they can also invest in things like tissue culture, to produce the plants on the larger scale. So, where we originally started out as UK propagation was our idea, it's ended up being more of a hybrid model, where we are still importing but we're importing from growers that we're working with to be more sustainable and then also propagating the plants which we can't get a good quality supply of from the tropics, bring them to the UK and propagate them to, hopefully, fulfil demand here as well. The third angle that we've taken, is we've started to work with people that we've become friends with over the last year or two in this space, who are serious hobbyists, people who have no intention of opening a store or becoming a nursery, but working with them to propagate the incredible species they have. I have a number of friends who enjoy propagating the plants they have, they enjoy growing them, they enjoy pollinating Begonias and chopping up miniature feelers and it's really been working with them to also create another area of propagation in the UK, so that we can also keep up with demand when we're stretched here because demand is still quite high and we can't physically grow the plants at the pace that we need them. So that's been another great way of reducing import demands as well.
Jane: That is so fascinating and are you still looking for new people from the UK to help you with this? I know I've got so many listeners to the show who are really keen and propagate some very unusual things that might be of interest to you.
Jacob: Particularly we're looking for really special plants. I think for us it has to be plants either we don't have or don't have somebody else growing for us or we can't get through the programmes that we started working with in Asia. I think, in the UK, there's a lot of hobbyists which have collections which rival botanical gardens, so yes, if you have these amazing plants that are pretty special, we're always open to chatting and discussing it. There's a few logistical overheads to work with when we do this, in terms of setting up people for planning inspections and things like that, which is becoming more necessary as time goes on, but if people are interested, just drop me an email or reach out on Instagram and we're always happy to explore these options.
Jane: Just going back to terrarium basics for a moment, is there one pitfall that everybody who builds terrariums falls into that you can help listeners avoid?
Jacob: I would say, and it's something I personally still struggle with to this day, is when I'm growing plants, often I grow a lot of plants outside of the terrarium to then put into the terrarium and I grow them in small plastic storage boxes for humidity and I always end up putting too much moisture in. What I've learned, over time, is that the plants need very little moisture at the roots as long as there's enough humidity in the air. It's really about that almost dry substrate but really humid air which is the key to growing these plants really well and it's been working with people who grow these plants way better than I could ever dream of, where I've really started to understand this idea of almost dry substrate. So, it should be a little bit moist but on the edge of being dry and then really high humidity and you can often achieve that by spraying the container that the plants are in, rather than directly spraying the plants.
Jane: Thanks for joining me today, Jacob, and for giving us all your brilliant terrarium info!
Jacob: Thanks for having me!
[music]
Jane: Thanks to Jacob and do check out the show notes for more details about Grow Tropicals and terrariums more generally. Do send me examples of your incredible terrariums! I love to see them and I know that you've got some cool things to show me, so do send me a note with some pictures, so I can drool.
Legends of the Leaf update: I'm writing as fast as my little fingers can manage and my little eyes can do the research and it's wonderful to be able to be writing this book. Helen Entwisle, my illustrator, is hard at work on the illustrations too. If you have already pledged but would like to upgrade your pledge, you can use code UPGRADELEAF15 for 15% off your upgrade to a higher reward. Maybe you've got no idea what I'm talking about! What on earth is Legends of the Leaf? You may be a new listener and not aware of this, but I am writing a book! It's going to be profiling 25 iconic houseplants and telling their stories and telling you how to make them grow really well in your home. I'm uncovering loads of cool facts about the plants that I'm covering, including Swiss Cheese Plant, Venus Flytrap, Aloe Vera, many of your favourites will be in there, so do check that out! You can visit my website janeperrone.com and you'll see a link called "I'm writing a book!" and just click on that and you'll get all the information about how to pre-order your copy.
I'm really hoping that I'll get some more pre-orders because once I get to 115% of my target for crowdfunding, that unlocks a new reward, and this is a really exciting reward - it's a 25 pack of postcards consisting of each of Helen's illustrations. This is the reward that I am so excited about because I really want these postcards! I love postcards and they're going to look awesome,! You're going to be able to frame them, or give them away to people, or use them as cards. They're very exciting. So if I get to 115% - and I'm at 107% at the moment - that will unlock that stretch goal, so please do support the book if you can. Thanks to everyone who's already done so. I've been doing some wonderful houseplant consultations with some of you on Zoom, checking out your houseplants and answering questions and basically everybody's got spider mites on their Maranta group plants, is the summary so far! I've got loads of those coming up. That reward level is now closed because I've had such a good response.
Oh, it's just started raining very heavily here, I don't know if you can hear that in the background, but the rain is pouring down, which is good because my water butts were getting empty and, as you know, I love some rain water for my houseplants! Anyway, where was I, yes so please do pledge if you can - loads of great rewards still there and if you pledge and I manage to get to 115%, that will unlock the postcards. 125% and there'll be a private author update video and if I get to 150% - this is really exciting - there'll be a bonus PDF of an extra chapter not included in the book. So there's amazing rewards out there! Please do support me if you can. If you can't support me, I totally understand and you will be able to get the book in all good bookshops once it comes out. How nice to have your name in the back of it - that would be pretty cool, right?
Patreon subscribers, keep your eyes peeled this week coming because I'm going to be putting out not one but two Extra Leaf episodes, one of which will be with today's guest, Jacob James, so if you are a subscriber at the Ledge-end or Superfan level then those extra bonus episodes will be coming in the next few days! That's one of the great things about being a Patreon subscriber, you get extra stuff which you pay for, so that's fantastic and these people help to keep the show going. If you want to find out more, check out the show notes at janeperrone.com where there is full information on how to become a monthly Patreon subscriber or make a one-off donation. If you don't fancy that kind of commitment, I'm cool with that, you can just give a one-off donation via ko-fi.com or PayPal.
[music]
Jane: Question of the Week is upon us and it comes from Stacey, who wants to know if anyone anywhere in the world is working on breeding non-toxic Aroids. I think Stacey has some pets and is concerned that they might be affected by nibbling all those beautiful Aroids. It's a really interesting topic because, of course, many Aroids are well loved food staples around the world. So we're thinking of things like yams and dasheens and Taro, which is from Colocasia esculenta - in fact, the oldest cultivated crop in the whole wide world! So some Aroids produce things that we can eat but we have to remember always with Aroids that they contain chemical components that can very much disagree with us and, indeed, our pets.
So, Aroids have got various things in them that are going to disagree with you. There are various things and I don't have the time or, indeed, expertise to go into the full chemistry of the Aroids but what I would say is raphides are the things that you'll hear mentioned when we're talking about Aroid toxicity. These are little, needle-like structures which hold calcium oxalate and if you consume the raphides then you're going to get an unpleasant feeling in your mouth. It's probably going to feel like burning and the throat's going to swell and it's not good for your kidneys either. As you may remember from way back in the Swiss Cheese Plant episode, if you eat the unripe fruit of the Swiss Cheese Plant, Monstera deliciosa, known as ceriman, before it's properly ripe, then it's those raphides that are going to give you that incredible acrid taste and cause your mouth and lips to swell. So there's clearly an issue.
I would be fascinated to know if Stacey's right and there is somebody, somewhere who is trying to breed an Aroid that is non-toxic. I have not heard anything of that kind and I would imagine it would be difficult because it is one of the central parts of the Aroid family's characteristics, that it has these raphides in it. Toxicity between different Aroids varies a lot though, so I wonder if there might be some species which have very low toxicity which would work. Of course, this is only a concern if your animals are munching on plants or you've got children who might be putting leaves in their mouth and therefore it is a live issue for you.
Why do Aroids do this? Well, it's obviously a strategy that they're using to stop things eating them in the wild. They do not want to be eaten by passing bugs, mammals, whatever, so they make themselves unpalatable and that's how they do it, by having this acrid taste which presumably would put most people off at the first bite. If you want to delve more into this world of Aroids and toxicity, Denny Baum's excellent book on Aroids is worth looking at. Unfortunately, it's very hard to get hold of and very expensive. Denny is writing a new edition of this book, which I'm very much looking forward to, but, if you can get hold of a copy, it's got loads of great information about various Aroids and their toxicity.
I think the other thing to say is maybe look for plants that are similar-looking but non-toxic. It's probably a much quicker way of dealing with it than trying to breed a non-toxic Aroid. I'm thinking of maybe things like the Banana, which you can grow indoors, it's usually Musa acuminata. The Dwarf Cavendish is popular because it's obviously dwarf. So those are worth thinking about because they have that jungly feel but they are, as far as I know, not toxic to any pets. Also, many of the Palm family, like the Areca Palm, Dypsis Lutescens, Kentia Palm, Howea forsteriana, are non-toxic to pets, as far as I know, so those are worth considering. Yes, it's a workaround that might mean that you can't have a load of Aroids if you've got nibblers in the house, but you can have these plants that look equally jungly and wonderful. And, of course, if you are somebody studying and working on the Aroids, in terms of their toxicity, I'd love to hear from you. Perhaps there's a project that I know nothing about? Do shoot me a line and tell me all about it at ontheledgepodcast@gmail.com which is also where you can send me your questions for the show.
[music]
Jane: That's it for this week's show, I will be back next Friday. Until then, my plant friends, have a great week. Bye!
[music]
Jane: The music you heard in this episode was Roll Jordan Roll by The Joy Drops, The Road We Used To Travel When We Were Kids by Komiku and Time to Move and Motivate by The Insider. The ad music was by the Heftone Banjo Orchestra, with the tracks Dill Pickles and Whistling Rufus. All tracks are licensed under Creative Commons, visit the show notes for details.
Subscribe to On The Ledge via Spotify, Apple Podcasts, Player FM, Stitcher, Overcast, RadioPublic and YouTube.
Terrariums offer endless possibilities for growing, but where do you start? Jacob James of GrowTropicals joins me to discuss containers, substrates and of course - the plants. Plus I answer a question about Aroids and toxicity.
This week’s guest
Jacob James is co-founder of GrowTropicals, a UK-based firm selling rare plants and terrarium supplies. You’ll find them on Instagram and Facebook.
Check out these notes as you listen…
You may see lots of pictures of terrariums containing cacti and succulents, but this is best avoided - they don’t do well with no drainage! It can work for a while if you are very careful with watering, but it won’t make for a long-lasting setup.
Instead, looking for tropical or subtropical plants that grow in the understorey - that means they can cope with lower light conditions you’d find behind glass.
If you’re starting out with terrariums, your substrate can simply be a drainage layer made of pebbles or leca (expanded clay pebbles) and your potting mix: in between should be a fine mesh layer to keep the two layers apart. This can be made of weed control fabric or the material used for sun blinds on cars.
Make sure the potting mix is fast-draining: create your own by adding bark, perlite, pumice to regular houseplant compost, or use bonsai soil or succulent soil. Some sphagnum moss on the surface can help things to stay moist. aim to keep the humidity in the vessel high, but the substrate fairly dry.
The substrate Jacob mentions - ABG - was first developed for Atlanta Botanical Gardens. There’s a useful post on Terrarium Tribe that goes into detail about the recipe, but it’s a mix of charcoal, tree fern fibre, sphagnum moss, orchid bark and peat moss.
Akadama originates in the bonsai world, and is made from baked volcanic clay. There’s more on it here. It has a high cation exchange capacity, which means it can hold onto nutrients well. More on cation exchange capacity here.
When it comes to choosing a glass vessel, you can use a larger setup - a similar enclosure to those for dart frogs, say. These can be hooked up to misting or light systems. Or you can set them up in smaller vessels such as fish bowls or glass vases. Check out places like Homesense in the UK to source these. Get some clear acrylic cut to size to act as a lid.
Rheophytes do well in terrariums: these plants spend part of the year submerged so they are used to be wet regularly.
If you’re looking for terrarium plants, check out aquarium plant suppliers: they tend to sell rheophytes that do well in terrariums, such as Bucephalandra and Cryptocoryne. Don’t just buy baby specimens of popular houseplants such as parlour palms and spider plants - they grow way too fast and too big to be suitable.
Shingling plants - which grow stuck to a vertical surface - are a good choice, such as Marcgravia umbellata aka monkey paws and rainbow marcgravia, M. sintenisii. Bromeliads also work well: heck out reptile and dart frog supply shops for these. Air plants also get on well, as long as you mount them to a piece of wood.
Grow lights are not essential, depending on your conditions. If you have a spot near a window that doesn’t get direct light, you can manage without, but you’ll see better growth by using a grow light. A single bulb that fits in a normal fitting can work fine. Check out GrowTropical’s growlight 101.
What can go wrong? The main thing is too much moisture, especially on sealed bottle-style terrariums, which induces rot. With more complex terrariums, some plants can grow fast and outcompete others. Cut back regularly to keep them under control. Use fertiliser sparingly, and ideally use a slow release pellet such as Osmocote placed in the substrate. It’s easy to add more, but not easy to take it away!
You can check out GrowTropicals’ terrarium plant range here.
Question of the week
Stacey asked about breeding programmes for non-toxic Aroids. Most aroids contain varying amounts of raphides, which are needle-like structures that contain calcium oxalate and make the plant taste very acrid, causing burning and swelling. As far as I know, no one is trying to develop non-toxic aroids, but tell me if you know different! YOu may have more success trying to grow jungle-ish plants that are not aroids, such as Musa acuminata, the banana plant, or the palms Dypsis lutescens (areca palm) and Howea forsteriana (Kentia palm). Check out Deni Bown’s book Aroids: Plants of the Arum Family for more on toxicity and aroids.
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!
THIS WEEK’S SPONSORS
LEARNING WITH EXPERTS
If you want to hone some new skills this spring check out Learning With Experts - the global classroom community that brings people together to learn from the best in the business.
Their range of courses covers everything from food and drink to photography and gardening. Why not Become an accredited garden designer and learn with world-renowned experts including influential Dutch garden designer Piet Oudolf and multi-award winning British designer Tom Stuart-Smith? Or take a course on herb gardening, natural beekeeping or growing veg. You can start whenever it suits and , you get to meet other gardening enthusiasts in the sociable online classroom.
Visit www.learningwithexperts.com/ontheledge and use promo code ONTHELEDGE to get 10% off your first course.
GREEN CHEF
This week’s show is supported by Green Chef, the The #1 Meal Kit for Eating Well. Green Chef makes cooking easy, with hand picked ingredients delivered right to your door, so you can get on with life while Green chef does the meal planning and grocery shopping.
Go to GreenChef.com/90ledge and use code 90ledge to get $90 off including free shipping.
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!
CREDITS
This week's show featured the tracks Roll Jordan Roll by the Joy Drops, The Road We Use To Travel When We Were Kids by Komiku and Time To Move and Motivate by The Insider. The ad music was Dill Pickles and Whistling Rufus by the Heftone Banjo Orchestra. All tracks licensed under Creative Commons.