Episode 108: Q&A special

A Maranta with an identity crisis. Photograph: Maija Gierhart

A Maranta with an identity crisis. Photograph: Maija Gierhart

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I tackle a clutch of listener questions in this episode. Here they are listed in order: 

Spent potting soil dilemma

Ryan from Chicago wanted to know what to do with ‘spent’ houseplant compost. I advised that, unless you’re fully changing the potting mix for a plant, you don’t need to remove all the soil from the rootball when repotting, although running it through with a chopstick or similar to improve aeration is useful. When it comes to potting soil that is surrounding dead plants, on the whole these can easily be added to a compost tumbler or bin, and can also be reused, but only if the plant hasn’t died from a disease or pest, and extra nutrients will be needed, and some aeration in the form of perlite, horticultural sand or similar. You can sterilise soil in the microwave or oven but this is only really necessary to create potting mix for seed sowing.

Chilli ripeness

A chilli ristra. Photograph: Jane Perrone.

A chilli ristra. Photograph: Jane Perrone.

Izzy asked how to know when chillis are ready to pick. The easy answer is ’whenever you want’ - green chillies are generally classed as unripe, although they are still used in many recipes. The flavour will be different depending on the ripeness of the chilli, but this does vary hugely from one variety to another. If you haven’t listened to my episode on chilli growing yet, do have a listen. There are some good instructions on how to make a chilli ristra here, and if you’re curious about my ‘Bloody Butcher’ tomato (an heirloom variety) there’s more information here.

Pilea gone wild

Ellie got in touch to ask about her Pilea peperomioides which is much bushier than the average Chinese money plant - it’s producing lots of side shoots and babies. I suspect the reason is that the top of the plant has been damaged (technically known as removing apical dominance) leading to the plant growing out at the sides. Pileas do vary considerably, and it may be that this particular plant has a slightly different growth habit than the average specimen of the species.

Maranta with an identity crisis

Maija has a Maranta leuconeura var. erythroneura - the red-ribbed kind - which has developed a single leaf that looks like the ‘Lemon Lime’ cultivar that’s so desirable (and in the UK at least, rare) at the moment. She has a theory that it’s a nutrient deficiency or a light issue: I suspect it’s not the former, because if it was, all of the foliage - or at least the newest foliage - would be affected, but this isn’t the case with Maija’s plant.

Spot the difference…

Spot the difference…

That said, I would recommend feeding the plant if it isn’t being repotted twice a year. A weak dose of regular houseplant feed every week or so during the growing season will certainly keep your plant in the best of health. I don’t think it’s light either, following the same rationale. It’s worth bearing in mind that the Maranta family exhibit pattern variegation (as opposed to the chimeral variegation of plants such as Monstera ‘Thai Constellation’ and Philodendron ‘Pink Princess’ - have a listen to episode 76 for a question that explains chimeral variegation further) which means that each and every variegated leaf looks the same, rather than having a completely unique pattern.

Is this an issue you’ve had with your Maranta? Do let me know!

Droopy Maranta

Hannah’s Maranta is suffering from another problem. She bought the plant three weeks ago, and despite following the directions for Marantas contained in The Houseplant Expert by Dr David Hessayon (my own plant bible!) the plant is starting to droop more and more each day. I explain that it’s worth checking the potting mix that the plant came home in, as it’s often more water-retaining than it needs to be for homegrown plants. The only way to really tell what’s going on is to check the rootball and repot if necessary.

Plants can go into shock after they come home with you, and take a while to settle in. Bear in mind that as temperatures cool, your plant’s growth will slow down, and so should your watering. Final warning: spider mite infestations can result in drooping, so do check for spider mite. Go back and listen to my spider mite episode if you aren’t sure what to look for and how to treat it.

Plants for air conditioned rooms

Jennifer has moved to Louisiana in the southern states of the U, and is looking for plants that will do well in air conditioned rooms. I suggest Sparmannia africana, aka African hemp aka house lime. It is a big, fast-growing plant that doesn’t mind cold draughts. It produces big clusters of white flowers in spring and will grow to 6ft tall very fast - you can always take stem cuttings if it gets too ungainly. Strawberry saxifrage (Saxifraga stolonifera - see episode 104 for details), Aspidistra elatior (the cast iron plant), Crassula ovata (the jade plant) and Persea americana (the avocado).

Want to ask me a question? Tweet @janeperrone, leave a message on my Facebook page or 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!


Join me at Lullingstone Castle in Kent in the UK on September 21 and 22 2019 for Cactusworld Live where I’ll be doing a live recording of On The Ledge at 1.30pm on September 21, featuring Tom Hart Dyke and Anne Swithinbank: there will be a giveaway of OTL merch, too, for one lucky listener, so don’t miss out! I’ll be holding a listener meetup after the podcast recording so come and say hi!

Then on Sunday September 22 come along to ‘An Audience With Jane Perrone’ at 2pm. There’s loads more going on, including a cactus and succulent show, plant sales from top nurseries, demonstrations and talks.

The following weekend I’ll be at the Garden Museum on Sunday September 29 for their Houseplant Festival: I’ll be helping out with the houseplant clinic, and there’s also the chance to take part in workshops and browse an awesome range of stalls from some of my favourite houseplant shops!



Jane Davis of The International Centre for Shared Reading got in touch to ask OTL listeners in the UK to send cuttings in a bid to help green up their HQ at Calderstones Mansion in Liverpool.

They already have some plants like this spider plant, but it needs some friends, so Jane and colleagues would love some more! If you can help, please drop Jane an email at janedavis@thereader.org.uk.


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Learn the secrets of houseplant styling with  The Joy of Plants .

Learn the secrets of houseplant styling with The Joy of Plants.


On The Ledge podcast is also supported this week by The Joy of Plants.

If you’re looking for houseplant information, inspiration and care tips, look no further than The Joy of Plants: learn about the three key houseplant styling trends for 2019, meet planty people from all over the globe and have a go at plant-based craft projects to help green up your home.

And while you’re there, check out their plant of the month for September, large-leaved Ficus, because whether you’re looking for an indoor bush that keeps things lively or an elegant green plant with designer foliage, there is a Ficus to suit your life.

You’ll find The Joy of Plants on
Instagram, Facebook, Pinterest and on their website, thejoyofplants.co.uk.

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This week's show featured the tracks Roll Jordan Roll by the Joy Drops and Oh Mallory by Josh Woodward. Ad music tracks are Dill Pickles and Whistling Rufus by the Heftone Banjo Orchestra. All tracks licensed under Creative Commons.

Logo design by Jacqueline Colley.

Jane Perrone