I am very interested in your Coleus bonsai. If you're successful I'd like give it a try myself.

Anxious to hear suggestions from others on your soil questions.

I saw a video last night on YouTube, from KW Bonsai in which he was using 50/50 turface and perlite as a medium for a lemon bonsai. Would that work for a plant that likes a lot of moisture in the roots, without drowning them since the drainage would still be good?

When I said soil-less mix in my last post, that may have been the wrong terminology. I think what I should have written and meant is a "sterile" growing medium.

That coleus sounds interesting. I have to say Thanksgiving cactus is one of those plants that have a range of recommendations for soil, light and watering that range all over the place. Mine is in old peat and really needs attention, yet grows and blooms although just once a year. I have South facing, glass block, basement windows that work great for stashing it for a couple months to get it to bloom. I want more!

@Pete: 'although just once a year.'

Sounds like you're saying it might be possible to bloom more than once a year. Not possible is it?

I had one for several years and really neglected its soil conditions but it bloomed faithfully every year.

I'm not sure which "blooming" thread it was, but there were some really impressive ones and some people commented on them blooming more than once a year.

My Thanksgiving Cactus bloomed/had flowers present for parts of last fall, all winter, and part of the spring. I never manipulated the conditions either, such as putting it in a dark room, or a cold room, or anything like that. It is in front of a large SW facing window.

I just placed it in a larger pot with a 2:1 mix of peat and vermiculite. It has abruptly stopped flowering in the middle of May and is now growing vigorously.

Interesting. Thanks. I always thought they were day-length dependent.

Here is the Flame Thrower Coleus. It is not yet in a bonsai pot, I am working on that. I have been pruning the branches every 3-4 weeks to encourage ramification and to keep it compact. It was originally 3 leggy stems that then flowered. I decided to cut each stem back significantly, just to see how the plant would respond. I believe I cut it back in Feb 2017. It responded quite nicely and filled out big time. I originally had it in gritty mix, it is now in 2 parts peat to 1 parts vermiculite. Here are a few photos:

Nice. Why did you change mixes?

Kyle -- I found that the coleus would wilt after just a few days in the gritty mix. It seems that the coleus roots like a moist mix, and I don't think the gritty mix could do that. To be truly happy in the gritty mix, I think the coleus would want water every 2 days, and I just can't water that often with my schedule and all the other plants I have. Once I placed it in the peat mix, it needed to be watered less often and does not wilt anymore.

However, I have found that I am now battling with fungus gnats in the peat based soil -- which leads me to my original question -- is there a sterile mix that would be more water retentive than the gritty mix that may work? 100% turface? 75/25 turface/vermiculite? 75/25 turface/bark?

Hope someone answers your question. I would like to maintain a couple or so coleus. I've grown them and then lose them while trying to overwinter under fl. lights. I have no doubt I've done probably 10 things wrong.

Hopefully this one makes it another winter. I anticipate that it will lose a lot of leaves. I think humidity is the main obstacle overwintering these. Mine is in front of a large and high SE facing window with unobstructed sun. It maintained its leaf coloration, so I think it was getting enough light.

I also have a Persian Shield that I purchased a few weeks ago. The leaf coloration is just amazing, almost doesn't look real. I believe these are very similar to Coleus in terms of cultural needs.

What Coleus plants do you have? Photos? What soil do you use?

No coleus for now. I gave up on them. I am using Al's 5:1:1 for everything now. And Dynagro Foliagepro.

Starting to use use Al's gritty mix for longer term plantings.