Episode 236: three houseplants for cold rooms
Transcript
Episode 236
[music]
Jane: If you're looking for a thrifty way to boost the health of the soil in your garden, Cover Crops are the answer. Thanks to On The Ledge episode sponsors True Leaf Market, you can rehab your soil the same way that farms do, by growing cover crops. True Leaf Market has been selling heirloom and organic garden seeds since 1974 and they offer a great selection of cover crop seeds, including their all-purpose garden cover crop mix; their most popular cover crop seeds for home gardeners. Get True Leaf Market's free beginner's guide to growing cover crops by visiting trueleafmarket.com and searching cover crop guide and order your cover crops online now at trueleafmarket.com using promo code OTL15 to save 15% on cover crop seeds. That's trueleafmarket.com, enter OTL15 for 15% off cover crops. Some restrictions apply. See the show notes for full details.
[music]
Jane: Hello and welcome to On The Ledge podcast, your source for houseplant advice, chat and a bit of relaxation here and there. I'm your host, Jane Perrone, and in this week's show, I'm discussing three plants for cold rooms; plants that will not care a jot if you turn the heating thermostat down, or even off, this winter. Plus, to chop or not to chop? I answer a listener question about root pruning.
[music]
Jane: I hope your week has been all right. Mine has been very busy. I've been on the road doing interviews for this here podcast, so coming up, you will be hearing about orchids, you will be hearing about greenhouses and you will be hearing about a group of succulents known as Aeoniums. Loads more great content coming up in On The Ledge over the next few weeks, so hit the subscribe button if you haven't done that already. A particular hat tip to my new Patreons: Rowena became a Ledge-end and Christina upgraded from Crazy Plant Person to Ledge-end. Thank you to you two wonderful individuals. They have unlocked exclusive bonus content and ad-free versions of the show, as well as my December mail-out, which is coming. If you want to get your hands on my December mail-out, you need to be signed up as a Patreon at the Ledge-end or Superfan level by 21st November. I'm saying that now because, well, we all need a few reminders for these kind of things because, let's face it, life-min is a lot! So sign up for Patreon and if you sign up for the two higher tiers, you will get a handwritten card from my good self!
[music]
Jane: And on with the motley. Let's look at the first of my three houseplants for cold rooms and this one is Solanum pseudocapsicum, otherwise known as the Winter Cherry, or you might see it also sold as the Jerusalem Cherry. I think many of us are looking at our fuel bills and wondering how we're going to cope with our plants this winter, so plants that could cope with low temperatures are a good thing. This is one plant that will be absolutely fine down to about 10C during the winter. If you've never seen it, let me describe it for you. I guess it looks a bit like a chilli plant, the little round berries start off pale yellow and they mature to bright red, passing through orange as they develop, and they follow on from little white flowers that will be very familiar to you if you have grown chillies.
Solanum, that genus might be familiar to you, is the nightshade family, of which tomatoes, chillies, peppers and potatoes are also a part, but do not be mistaken, Solanum pseudocapsicum is not edible. Do not put these cute little cherry tomato-looking berries in your mouth because they're not going to like you, you're not going to like them, it's going to be a bad reaction! Likewise, if you have pets and small children around who might mistake these for something that is edible, you need to keep them out of the way. This is a member of the nightshade family, Solanaceae, after all. It's a confusing family because, obviously, some of the plants are very toxic and then others, like tomatoes and chillies and potatoes, are things that we eat. So, yes, know your Solanaceae! But this plant is increasingly popping up in places like florists and supermarkets and garden centres, in the run-up to Christmas, because it's seen as being a rather festive plant. Now, I'm not that keen on "festive plants", to be quite honest. I like to have plants in my house at all times of year!
So what do we need to know about this plant? Well, you might find it growing outside as a garden plant where you live. Certainly in the UK, it has been naturalised and there's one round the corner from me, quite a large bush, outside somebody's house, which is doing very well. If you put it in a sheltered spot in a temperate climate, like we have here in the UK, or, indeed, a tropical climate, it will grow like billy-o! It actually comes from South America, including Argentina, Bolivia, Brazil and Uruguay.
The Winter Cherry has been in cultivation for a really long time. I think the botanical Latin name was first published in 1753. So this is a plant that's been extensively bred and spread around the world, which is why you will find it naturalised in many countries. This is considered invasive in some countries, including Australia, because it does that thing of crowding out natives and causing problems for those species. I can understand why because the little cherry like fruits, they do drop and seed everywhere. Where I've had this plant outside it does seed very readily. I can imagine, in a warmer climate, this could be a big problem. So if you do buy this plant and you're in a warmer climate, do take care and don't just chuck away your plants because you could be causing an issue for native plants.
Why Jerusalem Cherry? Well, it's obviously not from that part of the world. It's not from the Middle East, it's from South Africa, as we've already heard, but it's one of those common names that's come along. I guess somebody saw it growing in Jerusalem at some point and thought that it was from there? It's just one of those common names. I like to call it the Winter Cherry because that's less confusing. You'll also sometimes see it sold as the Christmas Cherry or, again confusingly, the Madeira Cherry; not from Madeira either! There are loads, and I mean loads, of synonyms for that botanical name. It's obviously gone under many, many names over the years. I think there's at least a couple of dozen of them. So you might see this plant sold as Solanum capsicastrum, or Solanum compactum. All of these names refer to this same species. I think at one point there was a belief that there were two different species, but I think it's been established now that they are all part of this same family, so thanks, taxonomists, for clearing that one up, but unfortunately, we've been left with a whole bunch of names that are inaccurate, which still hang around like a bad smell!
If you want to keep a Winter Cherry inside, then the clue is in the title of the podcast; it needs a cold room! Do not put this in a central-heated room next to your fire at Christmas time and think it's going to enjoy life. It really isn't! If you've got rooms like conservatories, or rooms where you're just turning off the heating at night, or keeping it quite cold, this is a good location for this plant. It prefers not to be blasted with heating. It doesn't want to be frozen either, it's not going to tolerate a hard frost, but if it's just cold, the temperature it might get down to in your house if you keep the heating off in cold weather, 10C, that's about 50F for those of you still living in the past. I jest! I don't want to start a centigrade/fahrenheit war here! It does like to be kept on the moist side of things. This is one plant where you might be watering it every few days rather than every 10 days, to just keep that potting mix moist. Do not let it dry out. Do not let it sit in a stuffy central-heated room because that's when your old friend the spider mite might decide to take up residence.
Now, normally, these Solanum pseudocapsicums are treated like pot plants and I'm using that term in a very specific way to mean a plant that is usually discarded after a few weeks when it loses condition, but there is no reason why you can't keep it going year 'round, if you can keep those growing conditions cool inside, in the winter, then maybe put it outside once the risk of frost has passed in about May, if you're in a temperate climate like mine. It will do nicely outside. I've got one that's bedded out in the garden at the moment and I'm planning on bringing it inside to my conservatory for the wintertime. There are lots of cultivars of this plant out there. It's been bred quite widely, so you might see ones that are bigger, smaller, have particular characteristics, but they're all the same species, this Solanum pseudocapsicum. In fact, there are literally dozens of synonyms that are considered by the taxonomists to be incorrect for this plant. So, as usual, we face the usual confusion, but just remember that it is Solanum pseudocapsicum.
[music]
Jane: Now, I know you're all desperate to find out what plant number two is, but let's deal with Question of the Week first. Today's question comes from Stephanie, who wanted to know about root pruning. Stephanie has a root-bound plant, but doesn't want to put it into a larger pot for logistical reasons. Stephanie, I've got you here! I totally understand what you're saying. So how do you root-prune a plant to keep it the same size and keep that pot size the same, while refreshing the potting mix?
Well, I think sometimes people can be a little bit too delicate with this particular task. If you root-prune, you will find that the plant will, generally, if it's healthy, respond very well and quickly put out new roots. If you want to get brutal about it, you can literally take the plant out of the pot and, assuming that the whole root ball comes out in one single mass because it's already quite root bound as they tend to do, you could just, if you wanted to, get a serrated knife or a pruning saw and literally slice through the bottom of that root ball. It sounds really brutal, but it usually works pretty well, particularly on things that have a tendency to get root-bound, like Dracaenas and ZZ Plants, that's Zameocolcus zamifolia, for those of you who like the long Latin names, those kind of plants with those juicy roots that tend to get really big. You can just slice through the bottom. It's as easy as that and put the chunk that you take off on the compost heap and then just go round teasing out the roots that are poking out. You could even also just slice down the sides again in the same way, like you're cutting up a pepper, and just cut away the roots at the side. That will work absolutely fine with a lot of those very vigorously-rooted plants.
The main thing to do is, when you're root-pruning, the remaining roots are facing outwards and are going to get a chance to grow into the new substrate that you're putting them into. Depending on the state of the substrate, the state of the root ball, you might want to try to knock off as much of the old substrate as possible, particularly if you're not giving the plant a bigger pot. You can sometimes wash it away, you can sometimes knock it away just by banging the plant on the table and gradually working in with your hands and getting rid of all that old substrate. Then you can also have a really good look at the state of the roots too and check that they're nice and firm and that there's nothing that's deteriorated or become slimy. You sometimes see, when you get root rot, that the rest of the root has rotted away and you've just got the central core left and if you've got any of those roots where suddenly this root starts out nice and fat and then suddenly you've got this little tiny string coming out of it, usually that's a sign of a bit of root rot. So make sure you trim away any roots that look like that or damaged in any way.
When to do root pruning? Well, the best time is as the plant is heading into an active growth period. So now here we are, in the UK at least, we're coming into autumn, probably not necessarily the best time to root-prune. It depends though. It depends what you're pruning. If you've got a plant that grows quite vigorously year-round and lives in a tropical climate, then it's probably fine to do it now, as we're into early September - should work okay. I wouldn't be doing it to many houseplants in the depths of winter, unless you can possibly avoid it, because you're going to prune that plant and the roots won't necessarily grow that much until spring. It depends on the plant. As I say, for things that are not in a massive dormancy period, it's probably going to be fine, but if you want to go for best practice, then wait 'til spring. If you've got a question for On The Ledge, do drop me a line to ontheledgepodcast@gmail.com. Yes, you can use Instagram, yes, you can use Facebook, but if you send an email, that way you can send pictures and loads of information and also, my scattergun brain doesn't forget about you so easily! So drop a line to ontheledgepodcast@gmail.com and I'll do my darndest to help you out.
Before we get back into plants for cold rooms, one other event reminder. The Plant Rescuer, aka Sarah Gerrard-Jones and I are hosting a plant swap and plant sale at Fade to Black in St Albans on the 17th September 2022, from 10:30 to 13:00. So if you can make it, please come along. We're raising funds for the World Land Trust. Bring along plants, or bring along some cash. Now, it's time to hear from my other podcast sponsor this week, then we'll be back to our planty chat.
[music]
Jane: This week's show is supported by Kinder World, the free mobile game about houseplants, healing and practicing kindness. I have to confess, mobile games aren't really my thing, but I downloaded Kinder World last week and I'm loving it! What's it all about? Well, you take care of virtual houseplants by taking care of yourself in the real world. Kinder World's design philosophy is simple but powerful, helping people heal from the stresses of everyday life by being part of a kind community. Kinder World has a full-time wellbeing researcher on board, to make sure the game's goals are all grounded in science. From decorating your own cosy space, to caring for houseplants and choosing delightful, artisanal pots for them, Kinder World is your safe zone. Kinder World is available to download for free in the Apple App store or Google Play. Join the Kinder World community now and find out more at playkinderworld.com
[music]
Jane: Welcome back to my trio of plants for cold rooms this winter. Plant number two is African Hemp, Sparrmannia africana. Now, this one, well, it looks a bit like a Lime Tree, Tilia cordata, actually, with these big hairy leaves that are very tactile, quite rough, hence one of its other common names, the House Lime, then these white flowers, which I think look a bit like a cross between a Horse Chestnut Flower and a Japanese Anemone. The similarity to the Lime Tree isn't that surprising because they're both members of the Mallow family, the Malvaceae, which includes, also, things like Hibiscus and, obviously, the genius Tillia, which includes Tillia cordata, the Lime. The Sparrmannia bit? Well, the genus was named after Linnaeus' son, Anders Sparrman, who also, not surprisingly, loved plants. This one can get down to about 7C/45F. It needs really good light. This is the plant that was traditionally depicted growing in big, draughty country estate homes in the United Kingdom. It first came to Kew Gardens and got spread from there. I think it was about the turn of the century, about 1800, that happened, but it has not been popular as a houseplant for quite some time. It does get big, you're talking about a good 6ft tall, and it does need good light. So you can imagine, if you're in one of those big old houses, you could have this on a landing in a giant floor-to-ceiling window and it would do wonderfully and it wouldn't care about the fact that it got rather chilly at night.
This species comes from southern Africa and Madagascar, where it grows as an evergreen. It's either a shrub or sometimes it gets tree-like in its size. Despite the hemp in the common name, it's not that closely related to Cannabis sativa. Now, of course there are variegated versions of this out there, if you choose to embrace the world of variegation, but you're going to have to hunt around a bit harder to get hold of them. One of the things that's unusual about this plant is the fact that the stamens on the flowers will actually move when you touch the petals. This is a characteristic you get on some other plants as well, like Mahonias and Berberis, which are both garden plants. If you do touch them with your finger, they sort of move outwards and extend and, apparently, this aids pollination. I found a piece from The Garden from January 1873, which describes Sparrmannia africana, noting: "It is also remarkable on account of its being furnished with irritable stamens which expand slowly if touched, more especially during bright sunshine. This action differs from that of the stamens of B**erberis, which contract closely around the style, while these expand or recede from it." He's absolutely right, I've watched a video of, I think it's Mahonias, which do the same thing. So, yes, fascinating little thing to watch if you do get one of these in flower!
Quiz question: Can you think of another flower that responds to its stamens being touched? Many plants in the genus Opuntia do this as well, but they respond more like the Berberis and Mahonias, drawing the stamens in to the centre. If you want to get fancy, you can call this 'thigmonasty', which is basically a plant moving in response to touch.
Now, like the Winter Cherry, this one needs a heck load of water. So, in the summer, you would be watering it pretty much every day. Come winter, obviously you need to be much more careful, depending on how much light it's in. That will dictate how fast it's using up water, but keep that potting mix moist. I did read some very wise advice in one of my vintage houseplant books, suggesting that this plant looks good in a combination pot. It suggests using it with the darker green of Ficus and Philodendrons. Now that would be nice. It just depends whether your temperature is getting super, super low. I don't think the Ficus would be too bothered about low temperatures but the Philodendrons, you need to be a tiny bit more careful depending on what you've got. So, yes, it's worth experimenting with this plant and getting hold of it if you can. Another great one for a conservatory. You do need room for it though. It does get big.
Now my final plant for cold rooms and it is Fatsia japonica, the False Castor Oil plant. As the name suggests, this one comes from Japan and Korea, Japan also being home to another one of the very, very tough, cold-tolerant houseplants we know about, Aspidistra**, also known as the Japanese Aralia, quite common in gardens and there are a few choice variegated cultivars, like Spider's Web and Variegata. But do not buy this plant and put it in a stuffy, central-heated room. It will not like it. It will lose all its leaves and be very miserable. If you've got a cold room in winter, lots of bright light, this one could be a goer, or you could bring in a plant that's been outside over the summer and it will do absolutely fine in a cold location.
This one's a member of the Aralia clan. One fact I found out recently is that the Japanese call this plant Yetsude, apologies for my pronunciation, and that means 'eight fingers' and you can see why, from those highly-lobed leaves. Don't get this one confused with the other false Aralia which is Dizygotheca elegantissima, or also known as Aralia elegantissima. This one won't take as low temperatures. It's got very, more finely-cut leaves. It looks a bit like the aforementioned Cannabis sativa, actually, but it doesn't take as much cold as the Fatsia, so if you really are talking about a cold room, it's the Fatsia japonica that you want and it will get down to around 10C/50F with absolutely no problem whatsoever.
Like the other plants, it does need reasonably high humidity. This would be a good one for a light office atrium, or something where maybe the heating's turned off at night. This plant will do nicely in there, provided it's not too hot when the heating comes on. It will not be bothered about draughts, particularly. As long as it's not absolutely in a blast of frosty air, it won't be bothered. This is a reason not to keep it in a heated room. It does want to be in a room where the air is moist and its soil is moist. They're really cheap to pick up, you can get one from the garden centre if you go for the plain green one, really quite reasonably priced. They do grow large, so you have to be a bit fearless with the pruning on this one and if you get your plant to a decent size you will get the beautiful white clusters of flowers, which are rather nice too. It will take hacking back in spring, if you need to do that.
If you really don't want to worry about space, then you can go for the intergeneric hybrid and, if you've listened to last week's episode about Mangaves, you will know what that means. Fatshedera lizei, intergeneric hybrid between Fatsia and Hedera, the Ivy genus, is a smaller plant that will fit in smaller spaces but is just as tough. You could actually get both of these down to 5C quite happily, I think, provided that the soil isn't too waterlogged at the same time, which could provoke root rot. So there's some options there, you have quite a few options for those freezing cold rooms over the winter. There is a cultivar called Moseri, which is more compact than the species, which is worth looking out for, for growing indoors, just so you don't deal with quite so much of a monster!
So those are my three suggestions for plants for cold rooms. I should also say at this point, and I haven't bothered talking about them in this episode because I wanted to bring you things that maybe you hadn't thought of before, but do remember that most of your cacti and succulents will be happy in a cold room down to 10C or even colder in some cases, so do bear that in mind when you're thinking about your plant palette this winter and the things that you're going to maybe move into a warm room and the things that you're going to leave in the rest of the house where maybe the heating isn't going to be on. I think this is something we're going to need to think about, maybe heating some rooms that we're going to be in most of the time and leaving other areas of the home colder and therefore we need some plants to put in those colder rooms.
The great difficulty is the cold rooms which are very shady. That's going to be your biggest problem because there aren't really any plants that will cope with both deep shade and lots of cold air. That's where, of course, you might want to be opting for an LED grow light, LED being the most efficient electricity, thrifty form of lighting.
Well, I hope that's provided a little bit of inspiration and I'd love to hear from you, what plants you're thinking of growing in cold rooms this winter. There are lots of options out there, I've just suggested three in this episode that you might not have thought of, but please do hit me up with your choices!
That's all for this episode. I will be back next Friday, turning up like a bad penny in your pod app feed! Thanks for joining me this 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 Sundown, by Josh Woodward. The ad music was Whistling Rufus, by the Heftone Banjo Orchestra and And Never Come Back, by Soft and Furious. 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.
Turning your thermostat down this winter? Here are three plants that will thrive in unheated rooms. Plus I answer a question about root pruning.
Check the show notes as you listen…
A botanical illustraion of African hemp taken from the book Traité des arbres et arbustes que l'on cultive en France en pleine terre. Photograph: Rawpixel Ltd on Flickr.
Winter cherry - Solanum pseudocapsicum
This plant has several common names, including Jerusalem cherry and Madeira cherry, but it actually grows wild in South America, including Bolivia, Uruguay and Brazil.
This is a member of the Solanaceae or nightshade family, along with familiar food plants including chillies, tomatoes and potatoes.
Although its fruit looks like a chilli or a cherry tomato, this is a toxic plant, so do not consume it or let children or pets nibble.
This species will be fine down to around 10C (50F) indoors: give it bright light and moist air and avoid placing in centrally heated rooms.
Winter cherry pops up at plant sellers in autumn, ready for the festive season.
It can grow outside in sheltered spots in temperate climates, is naturalised in some countries, and has become invasive in some places including Australia.
It has been in cultivation for a really long time, and there are numerous cultivars and incorrect scientific names - you may see it sold as Solanum capsicastrum.
Winter cherry is often sold as a temporary ‘pot plant’ but could be put in the garden once the risk of frost has passed in spring to spend the warmer months outside.
African hemp - Sparmannia Africana
Sparmannia africana is part of the mallow family. Photograph: Liesbeth de Toom on Flickr.
Also known as house lime as it resembles the lime tree, Tilia cordata, and they are both members of the mallow family (Malvaceae).
This plant gets tall - 6ft or more - but can easily be hacked back, ideally in spring. Place it outside in summer if you can.
Sparmannia can tolerate temperatures down to 7C (45F) but needs really good light: it was a popular plant in large country homes of the past.
It comes from southern Africa.
Despite the common name, it is not closely related to Cannabis sativa.
Keep the soil evenly moist when in active growth, but allow it to dry out a little more over winter as light levels drop.
The stamens will puff out when the flower is touched, which is meant to aid pollination: this is known as thigmonasty.
If you are in the UK, Jungle Seeds sell the seeds of this species, and plants pop up periodically in specialist plant shops.
False castor oil plant - Fatsia japonica
A member of the Aralia family, which grows wild in Japan and Korea, just like another cold-tolerant tough houseplant, Aspidistra elatior.
10C (50F) (probably lower provided it doesn’t frezze hard) needs high humidity and bright light.
Dizygotheca elagantissima/Aralia elegantissima with finely cut leaves.
x Ftashedera lizei
‘Moseri’ is a more compact cultivar, ideal for pots; ‘Variegata’ and ‘Spider’s Web’ are two of the variegated cultivars of this species.
A rootbound plant will benefit from root pruning. Photograph: Jane Perrone.
QUESTION OF THE WEEK
Stephanie got in touch to ask about root pruning a plant that needs a refresh, but has to stay in the same sized pot. The best time to root prune is when the plant is in active growth, especially in spring.
Don’t be afraid to slice away areas of compacted roots, particularly at the bottom of the rootball: you can use a serrated knife or a kitchen knife. Remove any roots that are rotted, and tease the roots out where they are matted so they point outwards.
Knock off or wash away as much of the old substrate as possible, and replace with new. Make sure the rootball is well watered so that the plant can start to reestablish and does not experience drought stress.
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
KINDER WORLD
Kinder World is the free mobile game about houseplants, healing and practicing kindness. From decorating your own cozy space to caring for house plants and choosing delightful artisanal pots for them, Kinder World is your safe zone. Kinder World’s design philosophy is simple but powerful: helping people heal from the stresses of everyday life by being part of a kind community. Kinder World has a full time wellbeing researcher on board to make sure the game’s goals are all grounded in science. Kinder World is available to download for free on the Apple App Store or Google Play - find out more at playkinderworld.com.
TRUE LEAF MARKET
Thanks to True Leaf Market for sponsoring this week’s show. Download their free cover crop guide here. Get 15% off cover crop seeds at trueleafmarket.com with promo code OTL15. This discount is only available for cover crop seed products. Offer expires end of December 2022. Limit one use per customer.
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 Sundown by Josh Woodward. The ad music was Whistling Rufus by the Heftone Banjo Orchestra and And Never Come Back by Soft and Furious.