Episode 41: the Maranta group - Maranta, Calathea, Stromanthe and Ctenanthe




On The Ledge show

Summary: The Maranta group, aka the prayer plants, all share an incredible plant superpower: they can open and shut their leaves. If you've never spotted this slow but steady transformation, check out this timelapse video on YouTube.  It's a process called nyctinasty, but how does this work? There's a great explanation here, but in essence a little organ called the pulvinus at the base of each leaf swells and shrinks to help the foliage move. They're also one of THE houseplants of the moment, because they all have intricately patterned leaves that the current generation of houseplant fans just love. Here's a rundown of the four clans of Maranta, most of which hail from South America: The plants that gave the group their name! They were named after a sixteenth century Italian botanist and physician, Bartolomeo Maranta, and have been grown for centuries as houseplants.  There are three types you are most likely to see: • Maranta leuconeura kerchoveana (rabbit tracks) • Maranta tricolor aka M. leuconeura erythrophylla (herringbone plant - pictured above) • Maranta leuconeura massangeana 2. The Calatheas The plant taxonomists have thrown us off the scent again by reclassifying the genus of this plant from Calathea to Geoppertia, just to let you know. For now I am sticking with Calathea. Here are some of the houseplant highlights of the genus... • Calathea makoyana (peacock plant)
 • Calathea ornata (pinstripe plant)
 • Calathea lancifolia (rattlesnake plant)
 • Calathea orbifolia 
 • Calathea roseopicta - specifically 'Dotty' (pink accents) and 'Manoa Blush' (slivery) 
 • Calathea zebrina 3. The Stromanthes These are mostly known at present through the extremely popular Stromanthe sanguinea 'Triostar', but Stromanthe amabilis is also worth hunting for.  4. The Ctenanthes This genus is probably the hardest to find, but seek out Ctenanthe oppenheimiana 'Tricolor' and the silvery-leaved Ctenanthe lubbersiana. I am a big fan of Ctenanthe burle-marxii, too, named after the Brazilian landscape architect Roberto Burle Marx. It's on my wishlist, so let me know if you know where to get one in the UK! So that's the Maranta group, but how do you look after them, and are there any new varieties we need to be aware of? I talk to Paul Holt, creative director of N1 and W6 garden centres in London, to find out which of the Maranta group are proving most popular with his customers. We also cover the perils of spider mite, how to keep humidity up at the levels the Marantas need, and the best potting mix to use when repotting. Here's a list of the newer cultivars Paul mentions: • Calathea 'Network' (Paul recommends this as being particularly easy to grow if you are a forgetful waterer!) • Calathea 'White Fusion' - this one has incredible cream, white and green variegation and is very high on my wishlist! • Calathea 'White Star' - this one's all about the white stripes. • Calathea leopardina - a refined, elegant plant that doesn't get too big. • Question of the week Andrew sent me a question about his new cactus; he wants to know whether the brown spots are corking, fungus, or something else? "Is it safe to put with my other cactus plants?" he asks. First off, I always recommend a quarantine period for new plants where you keep them away from the rest of your collection for a few weeks. Particularly if you suspect a problem with the new plant.  There are loads of reasons why cacti get marks on their skin, but one common issue is corking - it's cosmetic rather than a serious problem. Here's a useful guide on what corking is and why you shouldn't worry about it. The same site has advice on physical damage to cacti and sunburn. Incidentally, if you can ID Andrew's cactus do let me know! Want to ask me a question? Tweet @janeperrone, leave a message on my Facebook page or email ontheledgepodcast@gmail.com.  On The Ledge talks, live show and houseplant chats  I announced in this week's podcast that I am a special guest at Gardeners World Live in Birmingham on June 14 on the Blooming Interiors stage - check out the schedule here. I am also going to be at the Hampton Court Palace Flower Show on the afternoon of July 4 giving talks on houseplants in the roses theatre - do join me if you can. And on the evening of Friday October 26 I'll be bringing a live show of On The Ledge to the RHS London Urban Garden show, with special guests including Alys Fowler and all kinds of leafy fun! Put those dates in your diary NOW! Buy me a coffee!  If you like the show, please do go and rate and review On The Ledge on iTunes, 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 buy me a coffee! A donation of just £3 helps keep On The Ledge going: helping to pay for me to travel to interviews, and for expenses like website hosting and audio equipment. Don't forget to join the Facebook page for news of what's coming up on the show and bonus blogposts! Credits This week's show featured Roll Jordan Roll by the Joy Drops, An Instrument the Boy Called Happy Day Gokarna by Samuel Corwin and Oh Mallory by Josh Woodward, all licensed under Creative Commons.