I most climes, M. pudica would do well on a windowsill -- which is what I do. I used to keep them in terraria, but the humidity and temperature are low here only in winter.
How cold does it get where you live? I doubt M. pudica would appreciate frost. Fatboy would know.
Hmmm...I wasn't aware that M. pudica was an acid-loving plant...I've been using a combination of the usual Superthrive and a putrid-smelling liquid fish+liquid kelp solution (pudica makes a great "guinea plant!").
Remember to soak the seeds in hot water overnight before planting. Plant only those that swell.
I have yet to grow M. pudica in a soil mix for coprophytes, but I may try it soon (in joke).
M. pudica doesn't like being blasted by wind (or even a fan!
, so protect it from any strong wind whatsoever if you venture to grow it outside.
My growing conditions:
semi-sun, but full sun would be better. I'd provide additional artificial lighting (via fluorescent growlights) if the plants seemed to mind the lower light at all
watering: I treat it like a particularly tough Fittonia in that I keep the soil moderately moist, avoiding soaking saturation or letting it dry out
humidity is high, but not as high as in a terrarium
soil: to germinate, I used a light mix blended for seed-starting, but I repotted into a regular potting soil (not peat-based is my preference)
to soil, I added a balanced granular slow-release fertilizer in addition to some water-retaining polymer crystals (brandname "SoilMoist")
the mix is topped with long-fiber sphagnum, which retains even more water, allowing me to forget about the plants for a long period of time
fertilizer: v.s.
temperature: ranges from 55F or so in winter to 100F in summer...a warmer winter temp. and a cooler summer temp. would be better...more like 65F to 80F
water: distilled or RO--I don't think M. pudica would appreciate tap water
if you know the T.D.S. level of your tap water, however, I think anywhere below 100 P.P.M. would be OK
BTW, they are now sent
Chris