Ken, thanks a bunch for such quick response! The nursery did pot it in dirt. But they also kept it with the original dirt it had. To answer your P.S., the plant wasn't in the ground but actually in one of those black plastic bag kind of coverings. But it's a good advice you're giving me here. Yes, we are at the top of summer; and though this summer is not too hot as past summers, still I think the sun is showering down twice its radiation down here. So it's good to know if I need to transplant from ground to pot in the future. This time, however, it has been pot to pot. I don't know if that makes a difference. The plant was rather manhandled during the transplant. (It's not a responsible nursery as you would think, but rather a thoroughfare of plant-selling bodegas.) But during the 2-block walk home and finding it a proper place, I tried to keep it as comfortable and shockless as possible. Still, perhaps the repotting was rather traumatic. The person who did it might as well have strangled the plant! I'll keep on watering it each time the dirt gets dry. I read somewhere I should just water into the plate. Perhaps that's the best idea. I have the hunch my seller really doesn't know much about it. I asked them about how to care for it and certain specs of the mimosa and all the person told me was instantly contradicted upon researching the web. But the good news is the plant cost me little over a buck; so I'm not worried about the money, but I do hope the plant gets happy soon and thrives. I've brought the plant in for the night to see if perhaps it's getting cold just before dawn, though I doubt it should get so cold as to affect it. Perhaps tomorrow I'll keep it out of direct sunlight and see how it progresses. Well, so thanks again for the good advice and the quick response! X.B. This post was edited by Xavier_Bonet on Sun, Feb 17, 13 at 18:28

The fungus gnats could be an indication that you are either keeping the plant too moist and/or that your potting mix doesn't drain rapidly enough. Those are factors that 'could' be causing the severe leaf burn we see in the image. I'd get a decent, soil-less potting mix and add a bit of perlite and bark soil conditioner. The bark pieces will be much smaller than what you see as pine bark. We call them 'fines'. I've seen bags of this stuff at most of the big box stores and it makes a superior container medium amendment. I can't speak to the fertilizer issue. I am not familiar with the brand you mentioned. Just be very sure that you aren't using too much, too often as that could cause foliar burn, as well.

I think it is probably lack of water or temps. I am leaning towards temps, just because you said they were ventricosa and they are the sherman tanks of nepenthes. The brown spots look to originate from the veins which seems to tell me that the issue is from within and not an external attack. Ventricosa is technically a highland nepenthes. Although it will grow like a weed in most any condition. That tells me that humidity is probably not the issue since I grow mine if lower humidity. The next possibility is tempurature. You are in zone 9, how cold does it get there during the winter? Most neps, with the exception of a very few (2 that I know of khasiana and lamii [i think]) can withstand temps below 45. I had a ventrata burn at the growth points this fall when temps got below 50. It is doing fine now and started to branch and vine as a result, but I was nervous for a few weeks. (I haven't lost a nep yet.) Ventricosa if a very forgiving plant when it comes to water and light, but you should never let a nep dry out. Which judging by your experience, I am guessing is not the issue. That is what keeps leading me to tempurature. If that is the case, I think as long as you give them attention and get back to optimal conditions, they should bounce back. Leaves may die, but as long as new growth appears, then you should be ok. In it's weakened state try not to overwater. If leaves are dying, this is food for fungus now all it needs is a nice drink. If it is lack of water, then you should be fine too. Just make sure not to water log it for the same reasons as just mentioned. A little more light may help during the healing phase if the pitchers weren't already a reddish color before this problem. Otherwise, light is just right. Hope this helps...

Since there are buildings close by, I would think you'd want to solve the drainage problem. When you pump the water out, where are you putting it? I'm asking to find out how far away the safe space is where water can continue to leave the property on it's own. If you can show the drainage path in a picture, please add it. Many of the catch basins and underground pipes installed in private yards are 1) inferior -- too small -- to begin with. Typically, the pipe is 4" dia. which will not evacuate much, and 2) The underground pipes are often clogged from silt. They are especially prone to clogging if they are run with an inconsistent downhill fall. The type of pipe and plant materials nearby can effect them, too. A larger pipe and catch basin may solve your problem.