I've grown spider plant well in straight perlite. The studies on Fluoride and perlite indicate that the first watering can cause significant levels (almost 1ppm) but the levels drop quickly after that. The Fluoride levels in tap water are generally higher.

I also have spider plants outside that handle below 30f no problem. Some of those are growing epiphytically with no soil.

spider plants are notorious for not liking strong fertilizer though.

That's great you had success with perlite! I'll stop worrying about it then.
They might have had trouble with the cold since they were still so small. Not sure what it was otherwise.
Maybe they didn't like the soil at all?
I gave them fertilizer once or twice but very diluted.

Yep, I'm pretty sure that I only gave them fertilizer when they were in the vermiculite-filled egg cartons.

The other reason I think it was mostly a cold-related demise is because the roots looked alright while the leaves were very much dead. If it was a substrate problem, wouldn't there be a symptom in the roots? In the floor-dry, the roots turned black. Then again, I don't really know what I'm doing so I could be wrong again.

It's also possible that the floor-dry wouldn't be so bad if I had thoroughly rinsed it first. I tried sifting out the dust but there was a lot of particulate in the run-off after watering. If it really is similar to bits of fired clay then I don't know what the problem would be. A little alkaline, too absorbent and compacted maybe.

nil13, how do you grow spider plants epiphytically? I thought it might be possible since the babies on the mother grow roots. Do they actually thrive?

Completely unrelated: My DH is sick and he's making some super funny noises in his sleep. Not snoring exactly. Every once in a while he sounds a bit like he's pretending to be a ghost-cow. I thought it was funny anyways.. poor guy.

I just tie them to things with the roots packed in sphagnum moss. I have a bunch on a hardware cloth tower filled with gritty mix and wrapped in spagnum.

Really neat idea. I'm so going to try that!

Your DH probably has sleep apnea and should talk to a doctor about it. It can cause heart problems and be serious business. There are fairly simple solutions.

As for your spider plants, I wouldn't blame the floor-dry. I am growing a very happy spider plant in gritty mix made with 1/3 NAPA 8822 and it's been growing very well in that mix for two years. Your problems probably have to do with using it all alone. Not to mention not enough light and too cold temps.

Spider plants are very easy to grow. I have had them in ordinary potting soil for years, in hanging baskets. I don't think they are picky. But for the sake of weight i would use something like 511

This post was edited by seysonn on Tue, Dec 10, 13 at 2:07

nil13,

Your spider plant tower sounds cool, how about a picture?

Daniel

Spider plant has fat, tuberous roots that store moisture, so a fast-drying mix is critical so the roots don't rot.

I'm picturing the egg carton with the lid cut off & placed under for a drip tray?

Vermiculite is not good in a pot though may not be giving much trouble in an egg carton or yogurt cup because those are such small amounts. This stuff holds way too much moisture to be part of a potting mix and its' structure collapses, making it the exact opposite of what roots would like.

I don't know what this floor-dry stuff is, but does it maintain its' shape/chunkiness when it gets wet, or clump/pack up? Whatever is in your pots, avoiding packing it in there should help. If there are tiny air pockets throughout, that's excellent. Pebbles can't help with that, but could help keep clumping materials from clumping so much.

Don't worry about overwatering, your concern should be underdrying. If there are no tiny particles in a pot, it will dry soooo much faster. People who lose plants because they forget to water would have a hard time with this, but if you're the more common 'overwatering' type, this can mean the difference between plants that stay alive vs. those that die.

I might recommend an alternative source of water other than tap water, such as rain, melted snow, condensate from dehumidifier or A/C, distilled. It makes a huge difference if tap water is making one visibly ill (which it usually does over time.)

Thanks all for your wisdom. =)
It has been a wild adventure but I feel so bad that all those little spiderlings died in the process. More to come, eventually.
The survivors are doing well in a mix of perlite, potting soil, and bark chips. There's a little floor-dry in there, too, but emphasis on the little. They'd be doing even better if my cats didn't keep breaking into their grow space.

I do have a few looking very happy in plain perlite, so yes, that works. One of the cats gnawed off a couple babies without much for roots that I could see. To see what would happen I put them on a plate tucked under some moist moss from the yard (frog moss maybe) and they grew roots! They're healthy and look neat with the moss, too.

Back when this began, I had so many that keeping them outdoors was the best option. It was warm then, at first. The egg cartons were the recycled paper kind. I set them so that the base of one sat in the lid of another. I watered them enough to moisten the whole thing and then waited for it to dry before watering again, about every other day. As the roots grew they pushed the crowns up rather than growing much into the paper. Transplanted the tallest ones first. They did great until nights got cooler, and the floor-dry, and then the frost... Towards the end of the egg-carton stage, the cartons got spotty with a little mold. Expected mold earlier than it happened, though.

While floor-dry seems alright as a mix-in, I think you're right about it not letting the roots breathe. The feel of it seemed gravelly enough but it stayed too damp and probably compacted more than I thought.

Purpleinopp - Whenever my grandmother gives me a tour of her garden she shows off the bucket she uses to collect condensation from her wall-mounted AC unit. The water definitely makes a difference.

I've seen spider babies do the same thing - push themselves up. Cool. It sounds like things went well, for a first time. Thanks for the update. I left the stupid Poinsettia outside last night, it's probably toast. Mistakes of all kinds are unavoidable in gardening, all learning experiences, though none can help with memory, that I've tried yet. The moss thing you did sounds really cool, using what's available to your advantage. Good luck with the survivors!