Hi arborescent. That plants can be started indoors with the right conditions is good to know. Unfortunately, I don't possess any grow lights and we use dehumidifiers to prevent mould and mildew growth in the house and to dry our clothes, so I reckon I'll have to transfer my non-cacti plants outside when they're ready and winter has finished.
I plan to prune the Mimosas' shoots' tips (and probably the Phalaris' too) after they first flower to prevent them from getting too tall and to promote branching.
The M. pudica seedlings seem to be doing pretty good.
I've also heard that the cacti I bought were hardy as long as they're properly acclimated. I'm not too surprised to hear it, what with E. lageniformis being native to the Andes and the L. williamsii variety being able to survive in the Big Bend National Park, both of which reach quite cold temperatures from what I've read, but it's definitely promising to know. I appreciate your advice in germinating the former and will definitely put it into practice when I sow its seeds.
FWIW, my long-term plan for the cacti is to graft some of the L. williamsii on to some of the E. lageniformis once I have a few suitable candidates so that I can grow the former a little quicker and so that I can compare grafted and non-grafted L. williamsii with each other. I've still got a ways to go before I can attempt that though.
I'm curious arborescent, are you located in the northern or southern hemisphere? WRT to P. brachystachys, I've read that it's considered a weed to winter wheat crops and survives winter. If you're in the northern hemisphere too, and since it seems like you've managed to germinate yours, I might try to with some of mine as well. To that end, I'd like to know if there's anything special you did to germinate yours.
Thanks for making me aware of P. nexus. From what I've read, it does seem to be a plant that's well-suited to cold climes. Did yours require rooting hormones when you propagated it from leaf? Arkham's doesn't seem to have it in stock, but I'll definitely look around and keep my eyes peeled for it.
It's a shame that P. viridis doesn't grow in cold climates, and I'm thankful that people like Darren from herbalistics are spending their time selectively breeding plants that are suitable for tougher climates.