Episode 203: A visit to the Millennium Seed Bank
Seed germination experiments at the Millennium Seed Library. Photograph: Jane Perrone.
Transcript
Episode 203
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Jane: Kerching! It's time to talk banks in On The Ledge podcast this week. Before you switch away to another podcast, fear not, because I'm talking seed banks, not the boring, money kind! In this week's show, I visit the Millennium Seed Bank, home to seeds from more than 190 countries around the globe, plus I answer a question about stuck leaves.
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Jane: Before we get started with my visit to the Millennium Seed Bank, let me get my virtual dustpan and brush out to do a little bit of housekeeping. Thanks for all the fantastic feedback on last week's Jewel Orchids episode and if you've been inspired to give Jewel Orchids a try, Reshma has been generous enough to offer a discount code for On The Ledge listeners. Visit uglyplantling.com and use the code ontheledge10 for a flat 10% discount across all Jewel Orchids until 5 December, 2021. One use per listener and there's no minimum order. So thanks to Reshma for that and I do hope that some of you are going to be starting an exciting new collection of Jewel Orchids from now on!
A heads-up if you are in the UK: one of our listeners, Tom Cranham, has organised a fantastic event on Saturday 11^th^December, at midday, at Thornbridge Hall and Gardens, where he happens to work. If you've not heard of Thornbridge Hall, it's in the Peak District - beautiful part of the world - and there's going to be a talk by none other than James Wong and a rare plant sale by Grow Tropicals and you'll remember that Jake and James, of Grow Tropicals, joined me to talk to terrariums on the show a few weeks ago. So if you want to go along to this amazing event, do check out the show notes, where I will include a link. The tickets are £15 each, with all of that going to charity. You can get tickets direct from Tom - again, details in the show notes for that if you don't happen to be on Facebook.
On the Patreon scene, thank you to Molly, Anna, Raymond and Eva for all becoming Ledge-ends, Sara, who became a Crazy Plant Person. Just remember today, 19^th^ November 2021, is your deadline for getting your address up-to-date in Patreon. If you are a member at the Ledge-end or Superfan level, end of the day today, get it done! That'll make sure that your mail-out will go to the correct address and if you have any problems please, please do drop me a line - I will help you.
I do love it when I get messages from listeners, reminding of things I've forgotten, and one of these came from Anne this week, who reminded me that back in episode 79, quite some time ago, I talked about the Soil Sleuth. That was my gadgets episode and I talked about this tool, the Soil Sleuth, which is kind of like a big stake that you can stick into plant pot substrate, to tell if the plant needs watering. I said I would update you on how I got on with the Soil Sleuth and I hadn't done so, so apologies for that if you've been hanging on for that information. If you didn't hear the episode, as I say, it's a big, plastic, red spike that you poke into the soil and it's got little notches along that spike which allow you to take different depths of soil samples to see whether your pot needs watering. Anne wanted to know whether it was any good because she wanted to buy one as a Christmas present for a friend. What I would say, is it is good for big containers. So if you have containers over, I would say, 30 cm diameter, it's really excellent because you can get down deep into that root ball and really see what's going on. You're not relying on a soil moisture meter, which can go wrong to be fair, and sometimes often doesn't work if you're using particularly airy substrates. With this, you're actually getting a piece of the soil and each of those depths out, which will give you a real indication of how dry it is. So it's really good on big plant pots and I think that's what it's designed for, for interior landscapers to use when they're going 'round and they're looking at really big plant containers. If you've got smaller pots, it's not so useful because it's quite a chunky thing. It's like a very thick pencil width. It could be too big for some of your smaller pots. I guess you could make one of these, a smaller version, by just making some notches into something like a wooden kebab stick, if you fancied getting crafty. That would definitely work. So, maybe experiment with that, but if you want to buy it as a gift, I would say definitely go for it if you know that person had a lot of really large pots. Other than that, yes, my advice is always use your finger or just stick a kebab stick in there or a wooden lolly stick in for a few minutes and see if it's damp when you pull it out, that's the easiest way, and while you're doing that, you're also adding a little bit of extra air around the roots which is no bad thing.
Alistair got in touch about the Q&A on a cold conservatory in episode 201. Alistair was full of useful suggestions for what could be grown in this cold conservatory, suggesting citrus. It's a really obvious thing for a cold conservatory. I don't know why it didn't occur to my brain! They will do very well in a cold, but not frosty, conservatory. They really don't like central heating in the winter, so it would be much, much happier out in that cold conservatory than they would be either outside or in your warm house. Other things that Alistair mentions, along the same lines, are things like olives,Acacia**, Bougainvilla, Brugmansias. So if you've got those on the patio and they need somewhere to go, a conservatory is a great place for them. He also suggests Cymbidium orchids. That day/night temperature difference that you'll get in a cold conservatory actually helps to initiate flowering, so that's a useful thing. Alistair writes: "She could also grow some of the showier forms and varieties of hardy orchids, such as *Calanthe and Cypripedium". Awesome. He also mentions Clivia. Gosh, another obvious one there! Really good choice. Begonias, especially the hardier ones, such as Gryphon and Carolineifolia* are okay with low temperatures, as long as they aren't kept too moist. What excellent suggestions! Thank you, Alistair, for your thoughts.
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Jane: If you've been listening to On The Ledge for any amount of time at all, you'll know that I'm pretty enthusiastic about seeds. Sowing houseplant seeds is an annual event. Well, actually, a year 'round event here, at On The Ledge, so I was delighted to receive an invitation to visit the Millennium Seed Bank at Wakehurst Place, which is Kew Gardens' sister site in West Sussex. I got the chance to go deep underground inside the side vault, to find out how, why and what seeds are being preserved to make sure that whatever happens to the world, we don't lose that genetic diversity. It's worth pointing out at the beginning that, of course, Britain has a bit of a history of going out around the world and trashing places and taking what we wanted with very little care or attention of the indigenous people or the indigenous plants. The issues around ownership of these seeds and that genetic material is absolutely vital and this is something that Kew and the Millennium Seed Bank are starting to address. So this was one of the first questions I had for Lucy Taylor, who is seed collections assistant at Millennium Seed Bank, to find out how things are being done differently today.
Jane: The first thing I want to know is where are you getting the seeds from? Have you got intrepid people going out into the wild? People sending seed to you?
Lucy: Indeed we do, but we also have to absolutely, really carefully say that this is a partnership. We've got seeds from over 190 countries and it's a global partnership. It's a 50/50 exchange. So we will go out to countries, we'll have partners on the ground, we'll agree a target list with those countries and when they bring the seeds back to Kew, we do not own them. They always stay under the ownership of the partner country. They can decide what we do with them, so they can choose to make them available for research, or they can just choose to keep them safely banked. It's always up to them.
Jane: That's really important, isn't it, because in the United Kingdom we have a bit of a track record of going to other places?
Lucy: Yes, the good old bad days of the British Empire, which Kew was involved in and we are extremely aware of that.
Jane: It's really important, isn't it, that that kind of ownership is something that is thought about and thought through and also granting the nations that these seeds are coming from?
Lucy: Absolutely. The partnership extends to things like resources and training. We often host our partners over here for training, we will share knowledge and ideas and research and the latest and best techniques we have in conserving seeds.
Jane (studio): It's absolutely paramount that the seed that arrives at Wakehurst Place, to be banked in the vault, is viable, free of pests and able to last for as long as possible. So now, I'm going to find out what happens to the seed when it first arrives.
Jane: We're in the X-ray room. I'm seeing some pictures on the wall of X-rays of seeds. This is so cool because, what blows my mind about seeds, is just the sheer variety of shapes, sizes, colours and structures.
Lucy: Absolutely and there are days when I don't know what will arrive. I might have a package from Madagascar that turns up or I could have something from South Africa or Mexico. It's quite exciting to open the box of a new batch and see what we've got. When a batch arrives, I will unpack the box and I'll check it to make sure that everything's safe, everything's nice and clean and dry, there aren't anything wriggling or moving around.
Jane: Does that sometimes happen?
Lucy: Yes. I think we had giant earwigs from America once, but they have to be dispatched humanely and immediately. We can't possibly risk releasing anything out into the Sussex countryside.
Jane: No, indeed. So you've got rid of any insects. What do you do next?
Lucy: I will open up the collection and I will see what state is it in? Is it in the entire plant, which we really don't want, or is it just pure seed? What we want to do is clean away all the debris, leaves, twigs etc. Space in the bank is limited, so it's much easier for us if we just have pure seed. Once I've cleaned up all the debris, I need to find out what the state of the actual seed is, what's the contents like, is it full and nice and healthy, or is it infested with a bug, or infested with a fungus, for example? So the quality matters but, as you can imagine, collected from the wild, it's not controlled conditions, so trying to clean seeds is quite a long process, yes. It's a very manual process. They haven't yet invented a machine that completely does all the work we do. We might use sieves and bungs to separate all the different size seeds, we have machines called aspirators which separate things based on weight, so a heavy full seed will fall into the heavy fraction and empty seeds will just blow off into a light fraction. There's some videos online, I've seen, of homemade aspirators as well, which are quite cool.
Jane: I suppose you just want the seed. You don't want anything else that goes with it.
Lucy: No and not always possible to separate out all the infested ones, but if you've got a nice juicy bug inside, it probably weighs the same as a full seed, so we might not be able to aspirate it out, but the importance of X-rays, we will then find out the potential quality. This won't tell you if they're alive but it will tell you if it's potentially viable. If you have 10,000 seeds but 9,000 of them are infested that's very important to know because you need to know how many seeds you've got for the future.
Jane: Yes, that's true. I'm just looking at the shapes of these different seeds that are pictured on the wall. There's ones that look like feathers, there's ones that look like little kidney beans, there's round ones, sausage. Yes, it's amazing!
Lucy: This one, you can see a little, mummified bug in there.
Jane: Oh yes! Look at that! It made its way in.
Lucy: If you'd like to, we can do one quickly now?
Jane: Yes, that would be great.
Lucy: So, this is our marvellous, luxury machine. It's absolutely fantastic. It's all enclosed. It's safe for us to work here.
Jane: So we don't have to go out the room, like the dentist does?
Lucy: Absolutely not, no. It's actually designed for hospitals, X-ray and tissue samples, which is why it asks for patient names.
Jane: So do you put whatever this genus name is?
Lucy: Yes, we do.
Jane: That's brilliant.
Lucy: So we'll just open it up. What we've got here is a legume from Madagascar.
Jane: It's beautiful. It's like a round, shiny, red ladybird almost. Isn't that a beautiful seed?
Lucy: I love legumes. They're really good for seed banks.
Jane: Yes, nice and big size: you're not dealing with dust.
Lucy: Nice and big, no... There we go, so we've just popped it in and I'll just start up the machine. It should only take a few seconds. This isn't quite so good for small, tiny things like Begonias. I know there are a lot of houseplant people, but I'm afraid I twitch when I see them.
Jane: Their seeds are really dusty, yes. Just a big pile of dust. It's not very helpful.
Lucy: So I can't X-ray them. I have to actually physically cut-test them, i.e. slice them open with the scalpel.
Jane: Oh, wow! Presumably under a microscope?
Lucy: Yes.
Jane: That's amazing. I always worry when I get a packet of seed and you look at it and you go, "There's nothing in here," and you have to look really closely and go, "Oh yes there is! It's just so small, I can't hardly see it!"
Lucy: That's my life here sometimes. So what we've got, if I just change the contrast, we've got lots and lots that are good, but can you see here?
Jane: Yes.
Lucy: These are not so good, so there's something going on in them and I don't like that.
Jane: They've got some sort of shadows there, haven't they? Which, I suppose, could be they've dried out too much?
Lucy: I think it's probably infestation. Legumes are very popular with bugs. So here's a nice good one. It's nice and round and solid and consistent. Not so keen on these ones! But overall, that's a very nice collection, actually. That's not bad at all. We can never really eliminate all infestation from wild collections.
Jane: Do you ever X-ray and think, "Every single one's got a bug in it!"? Is it quite common to get a lot of infestations?
Lucy: It's not very common but it does happen. It's just part and parcel, really. What we can do is because this is a digital image, we can save it and send it to our partners to show them and say, "This is what happened. Perhaps could you try and collect a bit earlier next time? Could you put some kind of net around the developing seed pod to prevent infestation?" So it's a two-way communication. Quite often they'll try again the next year and next time I'll get a nice batch. So if we're happy with the cleaning and the X-ray, we then count them to find out how many seeds we've got and how many potentially viable seeds we've got, so then we can work out how many to make available for research etc, but once we're all happy with that, we can then take them down to our bank vault.
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Jane: I can't tell you how excited I was, heading down the spiral staircase to the vault and I wasn't disappointed because the door of the vault looks like a massive bank vault door, just like you'd see in the movies! Of course, it's there to protect the seeds from any natural disasters that might happen in the area. Once we got through the airlock and into the vault itself, Lucy showed me some of the treasures within. Apologies for the background noise but, as you can imagine, there is a lot of machinery going on to keep the conditions right in here.
Lucy: So this is our bank vault and this is underground dry room and it's very dry because we need to dry the seeds below 17% relative humidity to get them ready for banking. In here you can see these cold rooms coming off and these are where the seeds are stored. So you can just have a quick look through.
Jane: Yes, wow. I see loads and loads of shelves with what I would call mason jars; glass jars full of seeds.
Lucy: Actually, my colleague is in there right now. So it's -20C in there, -26C with the windchill.
Jane: Oh, okay. That's chilly. What's the biggest seed? Have you got any seeds that you have to store in a big, giant...
Lucy: Oh we've got massive, these Kilner jars, because we've got palms that are about this big. The thing is we've got to store everything from an orchid to a palm.
Jane: You've got different size jars.
Lucy: We're moving into these tri-laminate foil bags now. We think they're much better long-term, so we've got really teeny, tiny ones.
Jane: For the dusty ones. Oh yes, look at those.
Lucy: So when a collection is ready and it comes downstairs, we'll leave it here for about a month to make sure it's dry enough, test it to make sure it is indeed dry enough and then what we'll try and do, is we'll split it into two. We'll split it into what we call an active portion and a base portion. So the active portion can come in and out the bank if someone wants to research it, for example. Other universities, for example, can order seeds, so we'll get them out the bank and send a sample for them, or they might be used to grow on some plants for education purposes. Basically, they're coming in and out, but we don't want all the seeds to come in and out the bank, so we have a base portion that goes in and stays in. We don't want them coming in, warming up, cooling down again etc because we're not sure that's great for longevity.
Jane: So we've got an array of different seeds here. I'm immediately blown away by these blue seeds?
Lucy: Yes, these are fantastic.
Jane: So this is the Traveller's Palm. I know that palm. The Traveller's Palm is a beautiful palm, a really structurally beautiful palm, from Madagascar, pollinated by lemurs. The seed, it's bright blue!
Lucy: You see that so rarely.
Jane: That is an amazing colour for a seed, isn't it?
Lucy: It's really beautiful and some of my colleagues have been lucky enough to see this plant in the wild.
Jane: Wow and it's quite chunky. It's about the size of a haricot bean, I suppose? It's just this amazing colour of blue. That is a rarity though, not many seeds of that colour. I don't think I've ever seen a seed that colour.
Lucy: No, I've seen grey but not that kind of blue before. I'll be interested to know if there are any more out there.
Jane: Behind it, that looks to me like a piece of old-fashioned telephone wire, that you had on your dial phone, the bright yellow coil. So this is Prosopis** strombulifera, Chile.
Lucy: It's a legume. It was collected in 2005. So, along through the coils there are little seeds at different conditions all the way along.
Jane: Wow! Research into analgesic pain relief and antibiotic properties, that's just the most... I mean it looks like a bead or something?
Lucy: So I have to deal with all of this variation and work out what to do with it and how to bank it and keep it as safe as possible. We're going to keep this one in the jar because that one is deadly poisonous. That's called Obras preparatorias.
Jane: What's in the plastic bag and is that something to keep it dry?
Lucy: Yes. So this is a little silica gel sachet. So we want to keep the seeds dry but, unfortunately, in the cold rooms it's wet. It was a trade-off with the technology at the time. I believe they're now building seed banks where actually the chambers itself are dried. So we have to put them into a completely sealed vessel and this little silica gel sachet will go green if moisture gets in. Then we get it out and change the bottle.
Jane: These seeds are bright red and black. I'm presuming is it really quite toxic for us? I'm presuming you're not going to get it out for that reason?
Lucy: Yes, although funnily enough, if you eat one and swallow it whole you're probably going to be fine because it's a legume. It's really hard to break, but if it's cracked and you eat one, one of the symptoms is death.
Jane: Symptoms: Death. That's not a good sign, is it?! That is not a good sign.
Lucy: This is a neat one. It's showing you the longevity of some of these collections. This is all kind of new. We don't know how long some of these will survive, but this is a little Amaranthus that was probably collected maybe at Kew Gardens itself, in 1969. It was last tested in 2017 and 100% germinated.
Jane: Wow! It is amazing how long-lived some seeds are and I guess, particularly in these great conditions, obviously, that allows them to last the maximum possible length that they can.
Lucy: Yes, we're trying to give them the perfect conditions to last as long as possible, really. I've got a couple of houseplant ones here.
Jane: Yes, I'm seeing some familiar names here. It's interesting that you've got Mimosa pudica because that is one of listeners' favourite seeds to grow for our sow-along.
Lucy: I have to admit, I am too.
Jane: It's such a fascinating plant. I can quite see why that is.
Lucy: Mine are about 5 cm now and they're already doing the opening and closing, so I'm excited.
Jane: So fascinating. These were collected in 1971 in Nepal. Wow.
Lucy: Yes and they were last tested in 2006 and again they were 100% germination.
Jane: So you take a small sample of the seed out for that testing and then try to germinate them in their ideal conditions?
Lucy: Yes. We need to know these seeds are alive and stay alive and we also need to be able to turn them back into plants for restoration, so we need to figure that out. We will do that about a month after they've been banked and then we'll test them every ten years to check they're okay. You can see from this tiny, tiny little Begonia there, there's hundreds of seeds in there, but they take up such a small amount of room.
Jane: It's just a tiny, tiny amount, isn't it?
Lucy: So you can imagine how you can keep a huge amount of genetic material in such a small space. We reckon it takes about £2,000 to make a collection, but they're worth... you can't put a price on the collections that we've got here. If you were trying to have 200 Traveller's Palms, can you imagine the amount of space you'd need in a botanic garden and the watering and the care? But, no, they just sit here, sleeping.
Jane: That's why the seeds are such incredible things, isn't it? The sheer potential that is there and just waiting for that moment when conditions are right for them to burst forth. What about these big fellows at the back here? They look like chocolate truffles but I doubt they're edible.
Lucy: If only!
Jane: So these are Dioon Edule and they're from Mexico. Wow.
Lucy: I think some people do grow them as houseplants. I haven't come across them myself.
Jane: I can't picture that particular one but I love those seeds. They're the size of a small chocolate truffle. Those big seeds breaking open and germinating must be an exciting sight, but they are amazing.
Lucy: That one is also under threat from habitat loss and poaching, for the horticultural trade again. So you can see why we've got such a big door on the front. We need to be ever so careful. Do you think there's anything missing from the labels on these jars?
Jane: Well presumably you don't advertise what they are individually? You've got a bar code, so that you know, but other people might not be able to go, "Oh, I need to..."
Lucy: Yes, there's no names. We don't put names on a) because if anyone did manage to break in, we'd hope they'd freeze to death before they found what they were looking for. But also plant taxonomists, they do like to change the names.
Jane: They do!
Lucy: So we don't want to label a lot of plants and if they change it, then have to go into -20C and do all the labels again.
Jane: I can imagine that in itself must be a lot of work.
Lucy: So that label tells me the location, so I can go and find it in the bank. We have some collections where even if I go into the record it won't tell me where it was collected; the location data is kept secret. Well, if I can drag you out of the bank, perhaps we can go and see some things germinating.
Jane: Yes, let's go!
Lucy: This is our germination lab. Once we've banked the seeds, we then need to work out what they need to germinate. You can imagine, seeds in the wild, often they don't just spring up here, there and everywhere. They need the right conditions and the right cues before they germinate. This is the most exciting bit of my job for me, to find out what they need and try and crack it. We can do lots of things here. We've got incubators, as you can see all around us, and they range from 0C to 40C. We can do a day/night temperature difference, we can do a dry season and then a wet season. We can mimic a winter going into spring, anything to try and convince these seeds to germinate. We need to be able to germinate them because if we can't get them back into plants, how can we use them?
Jane: So that must be a real sort of detective work sometimes? You must have an idea from, possibly, the climate, but are there any particular seeds that just take you a long time to figure out what's going on?
Lucy: Absolutely, like, for example hollies, Ilex. We've got loads of them in the UK, but it turns out you've got to put them through two or three years of warm/cold stratification mimicking the seasons before they'll germinate.
Jane: Oh really? So they need those several stratifications in order to...?
Lucy: Absolutely.
Jane: That's so interesting. When do you give up? After the seeds, for about three or four years, you've been giving it this cold... there's still hope, you keep going?
Lucy: We don't. We still keep going. I think the longest germination test we've had running was about 500 days. We'll just keep going until we'll eventually... we need to work it out. We have some things that are harder than others and then we might have one of our germination specialists who will try and work on it and see what they need, but we usually get there in the end.
Jane: Well, it puts into perspective my own little home efforts at growing things! It's comforting to know that it's not always easy to germinate things though.
Lucy: No and sometimes it's not you, it's the seeds. We've even X-rayed commercial packets of seeds and there's not been anything in there, it's just been an empty husk, so it's not always you and sometimes they can look perfectly fine but, actually, they're not alive, so take heart that we struggle as well!
Jane: That's good to know. That is very good to know.
Lucy: Absolutely.
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Jane: More from the Millennium Seed Bank shortly, but now it's time for Question of the Week. I'm afraid I'm going to download a little bit in this answer, so apologies in advance for the upcoming rant. The question comes in from Sally. Don't worry Sally, I'm not going to rant at you because your question is perfectly reasonable! The question is regarding the unfurling of leaves and those leaves getting stuck. Sally has heard various plant YouTubers mention this and had some experience herself with a Philodendron Prince of Orange. The plant has been potted up to a slightly larger container and Sally thinks that the problem may have happened when she was moving the plant out of an IKEA greenhouse cabinet, as the new leaf was emerging and from the photos we can see that the leaf does appear to be rather stuck.
What does that actually mean? Well, a lot of these Aroids have leaves that emerge from cataphylls which are a kind of a rudimentary leaf. They don't really do photosynthesis. They're more there as a bud scale for the actual leaf and when the plant is ready to unfurl that leaf and get it out there in the world, it starts to emerge from the cataphyll. Some plants have persistent cataphylls that stay in place after that leaf has exited, some have cataphylls that fall off. This is often a thing mentioned on social media: "Ooh, how do you remove the leaf from the cataphyll?" I am the world's biggest fiddler! I call this me being 'barnacly', which means if I see something like a barnacle, I want to rip it off, but even I exercise extreme self-control when it comes to "stuck leaves"!
Please, please, do not use tweezers, your fingers, a knife, anything else to fiddle about with leaves that are taking their time to come out of a cataphyll. Why? Well, it's like imagining, "My baby is a bit overdue, therefore I'm just going to have a little wiggle around up there with a set of forceps to see what's going on!" As we all know, things take their own sweet time and the leaves will emerge in due course. What can happen, and I think this is what's happened with Sally's plant, is that a drop in humidity can cause the leaf to slow down in its emergence. So, best thing to do in this scenario, really, Sally, if you can, would be to put that plant back into the IKEA greenhouse cabinet, if you can. If you can't, you could always just stick it in a more humid place, or maybe even stick it in a clear plastic bag for a few days. You will find that that leaf eventually slips out lovely and has no problems. The risk of damage when you start fiddling around with those very, very young leaves is enormously high. Oftentimes people will think, "Oh, I've successfully removed it from the cataphyll. Oh great!" but then, "Why has my leaf got these funny marks on it, or this strange random hole?" Well, it's because you fiddled around with it when you shouldn't have done, so, sorry! That would be my strong advice.
Try to increase humidity around the plant in a way that makes sense to you. As I say, those are the methods I would recommend: moving it to somewhere more humid etc. I wouldn't keep the plant constantly sprayed with water, although that may help as well, it depends what your substrate is and how much light it's getting and so on. Humid air will solve this problem for you. As I always say, check the substrate, make sure it's not bone dry or waterlogged, so that water is reaching that tender young leaf as it develops. Do all of those checks and just wait. Just be patient. The leaf will emerge. If you've got stories of successfully removing leaves from their cataphylls, please don't @ me! Just be very smug and glad you've managed to do it, but really it's one of those jobs that people like to fiddle with. If you're looking for more jobs to do with your houseplants, and God knows I'm not because I've got enough on my plate without creating work for myself, then maybe do some propagation, maybe do some root pruning, maybe examine every inch of your leaves with a hand lens looking for pests, but please don't fiddle with unfurling or "stuck" leaves. Okay, rant over!
I hope there was some helpful advice in there, Sally, as well as my rant. I think it's one of those things that people get very worried about but, as I say, I've got a Philodendron, I think it's Imperial Red, and it's not getting enough humidity really. Sometimes the leaves do get stuck, but it does resolve itself and the plant is fine. As a result of me not fiddling around, the leaves, when they do emerge, are intact and okay. So there you go. That's my advice on "stuck leaves". If you've got a question for On The Ledge, drop me a line: ontheledgepodcast@gmail.com is the address and I would love to hear from you. I'm currently collating questions about Christmas-related issues. I've had some Christmassy Q&A questions. I'm asking for more of those to put together a Christmassy episode, so do get your Christmas-related questions to me. Maybe your Christmas cactus is already in flower? Maybe you are wondering how to stop your Paperwhite Narcissus from falling over. Whatever your festive inquiry is, do let me know and I will endeavour to help.
Now, let's head back to Wakehurst Place, where I'm finding out more about how the Millennium Seed Bank is helping communities around the world conserve their seeds.
Aisyah: My name's Aisyah Faruk. I'm a, what they call a conservation partnership for the MSBP.
Jane: So tell me what that involves. That's your official title. In practice, what do you end up spending your working day doing?
Aisyah: My typical working day is very varied. What I take care of is MSBP, which is the Millennium Seed Bank Partnership. MSBP is essentially a global partnership. I think we've got 155 city participating institutions from about 95-97 different countries and territories. My essential role is to coordinate and take care of those kind of partners around the world. My particular region is actually Europe and Oceania, those very similar continents that are very close together. What we tend to do is we work with partners to try and help them, or support them, in conserving their plant diversity, through seed-banking and also through training and knowledge exchange, so I do a lot of travel to my partner countries to talk to them about troubleshooting, talk to them about how to work with what they've got and also build capacity within countries to conserve seeds.
Jane: What are the challenges in that work? I presume there's so much habitat pressure around the world and competing demands?
Aisyah: Yes.
Jane: Does that impact on seed populations and taking care of endangered species?
Aisyah: Yes. We tend to focus, or, essentially, our partners tend to focus, on things that are extremely threatened within their particular countries, particular habitats that they're interested in. So we used to say the 3Es - endemic, endangered, economic importance - and we use as much of the tools that we have in our arsenal to actually cope with some of these big challenges. While populations are being extremely threatened at the moment, we're going through mass extinction, two in five plant species are in threat of extinction which is a big major issue and they're coupled with food security issues, so people who are dependent on some of these plants, or useful plants, are seeing that it's diminishing and knowledge is not being exchanged. So we do a lot of work not just in conservation, not just seed conservation, but also livelihoods as well, setting up community seed banks, for example, and, more recently, I've got a project looking at conserving useful, wild-harvested fruit and nuts in South Caucasus and Georgia and Armenia. So we're working with local communities to see what they find important in terms of the things that they harvest from the wild, bringing some of them into cultivation, storing them in seed banks, duplicating them here and things like that, really, and making them aware of sustainable harvesting. So we do a varied amount of things around here. I do have some things growing in the nursery. That's from that project as well.
Jane: Should we go and have a look? Let's go and have a look. I'm so excited! You've got a vial there?
Aisyah: Yes, there's loads of different seed banks around the world. Essentially, yes, we're storing seeds, but there are so many different seed banks out there and so many different purposes. So, if you think about seed banking, it's been around since, oh god, whenever people started growing food. You've got your European botanical garden seed bank and they have their own cultivated collections, for example, and a lot of their purpose is actually to grow on the collections and also to exchange with other botanical gardens through the Index Seminum, which actually started in the beginning of the 18th Century, which is fantastic. Then you've got agricultural seed banks, obviously, and that depends on which country you're in. So in the Caucuses', for example, they're big on their wheats and their breads and their pomegranates. I didn't realise how many pomegranates there were! They're really on that. Then, in Asia, you have the rice and the bananas and things like that. So it's very different... essentially agricultural foods seed banks and then you've got your doomsday seed banks, which essentially is the Svalbard crop seed bank and then the Millennium Seed Bank, which is all to do with wild species. We tend to say that we are like a bank, in that a lot of collections - although we are essentially a kind of doomsday seed bank - our collections get used quite regularly for research and restoration. It depends on the agreement that we have with our partner countries, obviously, because sometimes we have really, really threatened species and our partners are, like, "Yes, these are not to be touched" which is fine, but most of them are available for use. I know you've got quite a following in Australia, is that right?
Jane: Yes, lots of listeners in Australia, yes.
Aisyah: We've got a really, really strong relationship with the Australian Seed Bank Partnership. They're called the ASBP. They're fantastic, they do amazing work and they do a lot of active restoration as well. They duplicate their seeds to the MSBP, so a lot of the seeds that we have are actually duplicates of emerging collections which are within the partner countries. After the 2019 bushfire, the fire intensity was really out of this world. It was really, really bad. So, obviously, I think you remember the devastation that you saw, bushfires happen all the time, but that was never really seen before and for some of the species that are in Australia, some of them have very small, isolated populations. These small, isolated populations don't really have the resilience to cope with such intensity. So we got a call from our friends at the South Australian Conservation Centre and said, "We need some seeds sent back, particularly of this endangered pea called Glycine latrobeana"and the seeds from the population were actually collected in 2007, they duplicated some of the collections here and when they called up and said, "We need to restore some of the fire scars in Cudlee Creek" we said yes, perfect, sent them 250 seeds from this particular collection and then a few months later they sent us a lovely photo of them germinating and it's now being used to restore Cudlee Creek, which is fantastic! We want to, essentially, do more of that. A decade of restoration and getting more seeds to be used in that way would be fantastic.
[music]
Jane: Thanks to everyone at the Millennium Seed Bank who made me so welcome. Do check out the show notes for links to the Millennium Seed Bank website and more information about what they do. If you are a Patreon subscriber at Ledge-end or Superfan, you can listen to my chat with Ed Ikin, of Wakehurst Place, where we take a tour of the meadows there, which is fascinating. You can also hear some extra chat with Lucy about germination of seeds from the seed bank. Aisyah tells me the incredible story of the seeds that came from a sailor's wallet and germinated after several centuries!
I hope you've enjoyed this week's show. I shall be back next Friday, when we'll be talking thrips. I'm interviewing someone who knows thrips literally inside and out, to get the lowdown on the lifecycle and habits of these houseplant pests! Until then, remember: to plant a seed is to believe in tomorrow. 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 Overthrown, by Josh Woodward. All tracks are licensed under Creative Commons. Visit the show notes for details.
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South African orchid Disa uniflora growing in the glasshouses at Wakehurst Place. Photograph: Jane Perrone.
The Millennium Seed Bank holds a treasure trove of plant genetic material from around the world, including many of our favourite houseplants: I headed into the vault to find out how and why seeds are banked. Plus I answer a question about ‘stuck’ aroid leaves.
Soil Sleuth update: I talked about this tool in my gadgets episode: it helps you to check moisture levels in plants . It comes from the US and you can buy it from soilsleuth.com although I bought mine from interiorlandscaping.co.uk. My verdict having used it for a while: it’s great for bigger pots (diameter 30cm+) but may be too chunky for smaller specimens. You could make your own smaller version by putting notches into a wooden kebab stick!
The Millennium Seed Bank
Wakehurst Place in West Sussex is the sister garden to Kew Gardens in London: it’s home to the Millennium Seed Bank, a “doomsday” seed bank preserving seeds from more than 190 countries. Seed collections assistant Lucy Taylor and conservation partnership coordinator Aisyah Faruk show me around the place and explain how the seeds are saved, where they are stored and how Kew works with partners around the world to preserve the genetic diversity of plants.
Patreon subscribers at the Ledge End and Superfan level can listen to more fascinating insights from Lucy and Aisyah - including the 200-year old seeds from a sailor’s pocket - in An Extra Leaf 82. You can also hear my chat with Wakehurst Place director Ed Ikin, where we talk about meadows and American-style prairies at Wakehurst, in An Extra Leaf 80.
Here’s the entrance to the vault - designed to protect the seeds from all kinds of natural disasters. Photograph: Jane Perrone.
Here’s a list of the particular seeds we mention:
If you’re interested in reading more about Kew’s colonial legacy and what the botanic garden is doing to address structural inequalities in horticulture and botany, here is a statement by director Richard Deverell. Also check out the Instagram account @decolonisethegarden for an insight on how colonialism and the history of Kew and other horticultural institutions is being brought into focus by a new generation of campaigners.
The bright blue seeds Lucy and I look at are from the travellers’ palm, Ravenala madagascariensis.
The seeds that looked like chocolate truffles were Dioon edule, the chestnut dioon from Mexico, a plant that is threatened in habit by overcollection.
Prosopis strombulifera, the argentine screwbean from South America ,has the most amazing seeds that look like an old-fasioned telephone wire.
Mimosa pudica, the sensitive plant, is a popular choice for people getting involved in the On The Ledge sowalong.
The Australian pea that Aisyah mentions is Glycine latrobeana: the Millennium Seed Bank worked with the ASBP (Australian Seed Bank Partnership) who used seeds to restore Cuddlee Creek near Adelaide after the devastating bushfires of 2019. Here’s an article from the Kew website about the peat and this project.
Aroids sometimes suffer from ‘stuck’ leaves as they emerge from the cataphyll. Here’s Sally’s Philodendron. Photograph: Jane Perrone.
QUESTION OF THE WEEK
Sally wanted to know how to deal with “stuck” leaves on aroids.
This happens when the emerging leaf will not come free from the cataphyll, which is a modified leaf (often one that doesn’t photosynthesise) that envelops the new leaf to protect it as it starts to grow. The problem usually occurs when there is a drop in humidity as the leaf is emerging, which can cause it to stop emerging. It’s very tempting to want to help the leaf along, but the risk of damaging the very tender young leaf is huge!
So, despite the ‘hacks’ you might see on social media, my advice would be to please leave leaves alone! The best way to help is to increase humidity around the plant, either by changing its location or even temporarily putting a clear plastic bag over it! Also check the substrate and rootball to make sure the plant isn’t either bone dry or suffering from root rot, as a lack of water reaching the new leaf won’t be helping either.
Not sure what a cataphyll is? Seems like many growers and botanists aren’t sure either! Here’s an interesting discussion on the matter on the International Aroid Society forum.
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!
LEGENDS OF THE LEAF
How exciting would it be to get all the wisdom of On The Ledge condensed into a beautiful book?
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 Overthrown by Josh Woodward.