Episode 89: OTL houseplant sowalong part three

Sedum seedlings… Photograph: Jane Perrone

Sedum seedlings… Photograph: Jane Perrone

Subscribe to On The Ledge via SpotifyApple Podcasts Player FM,  Stitcher, Overcast, RadioPublic and YouTube.

This week is an On The Ledge sowalong extravaganza! We’re now getting to the nitty gritty - the actual seed sowing bit - so my dog Wolfie and I are off to my potting shed to see what’s sprouting there, plus I have special guest Robert Pavlis to answer a question about using wood ash on houseplants.

If you’re new to the sowalong, do go and check out episodes 87 and 88, which cover where to source seed and what equipment you’ll need. You can also listen to last year’s On The Ledge sowalong episode.

Scroll down for details of the seeds I am sowing and other things mentioned in this episode.

Here’s the mystery houseplant seed mix I talk about in this episode… intriguing! Photograph: Jane Perrone

Here’s the mystery houseplant seed mix I talk about in this episode… intriguing! Photograph: Jane Perrone

Don’t forget to share your seed sowing activities with me and other listeners using #OTLsowalong: join the Houseplant Fans of On The Ledge Facebook group to compare notes with other listeners, but do remember to add OTL sowalong as a topic to relevant posts.

  • I am sowing Coleus ‘Rainbow Mix’, Echinopsis obrepanda, Echinofossulacactus ochoteraneus, Echinopsis sylvestris, Coleus ‘Fairway’, mixed Plecntranthus, Sarracenia purpurea, Zamia furfuracea and Cymbalaria muralis ‘Alba’.

  • Hygiene is important when sowing seeds to prevent problems such as damping off. Remember to wash out your pots and trays with hot soapy water and rinse well with clean tap water before you sow.

  • Rainwater is usually recommended for houseplants, but when it comes to seeds, water with tap water or distilled water to discourage fungal problems.

  • Dampen compost before you place it in the trays: watering after sowing always results in disturbed seeds!

  • Make sure the compost is firm but not compacted: remember seeds need oxygen as well as water to germinate.

  • Really small seed can be mixed with horticultural/silver sand to make sowing easier.

  • Some seeds need exposure to light to germinate; others prefer to be covered - some need high temperatures of 20+C, others will germinate at much lower levels. Find out about what your seeds need before sowing.

  • Make sure you label seeds well with the species and date of sowing.

  • (I discovered that my apparently dead cape sundew (Drosera capensis) plants are actually resprouting after a winter in my unheated greenhouse! Hurrah!)

Question of the week

Peter wanted to know whether wood ash from his woodburning stove could be used on his houseplants.

There’s a lot of misinformation about wood ash and gardening out there, so I called on an expert for this answer. Robert Pavlis is the gardening expert behind GardenMyths.com and is the author of several books. Patreon subscribers of $5 a month or more can listen to an extended interview with Robert Pavlis in An Extra Leaf 25. Want to become a patron of On The ledge? Keep scrolling down to find out how.

Want to ask me a question about your plant? Either way, tweet @janeperrone, leave a message on my Facebook page or email ontheledgepodcast@gmail.com.

On The Ledge on tour…

I am talking about the magic of houseplants at the Highgate Literary and Scientific Institute on Tuesday April 9 at 8pm. Do join me if you can, entry is FREE! (Let me know if you’re coming and I’ll bring some OTL merch along…)


As I already hit my goal of getting 100 patrons before I hit my 100th episode sometime in June, I have decided that I need to up my game a bit and try for 200 patrons in the same time frame. GULP. Everyone who signs up as a patron before the 100th episode comes out will get the exclusive digital artwork promised to the first 100 patrons, plus something else yet to be decided - stay tuned! Any tier counts, so by pledging just $1 a month you could help me reach my target! If you want to know why it’s important for me to increase my number of patrons, here’s why.

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!

For those who prefer to make a one-off donation, you can still 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!

If you prefer to support the show in other ways, please do go and rate and review On The Ledge on Apple PodcastsStitcher or wherever you listen. It's lovely to read your kind comments, and it really helps new listeners to find the show.


This week's show featured Roll Jordan Roll by the Joy Drops, An Instrument the Boy Called Happy Day Gorkana by Samuel Corwin and Quasi Motion by Kevin Macleod. All tracks licensed under Creative Commons.

Logo design by Jacqueline Colley.