Carnivorous Plants/Tropical butterworts and extreme heat
QUESTION: I've run into some oddities with my pinguicula cyclosecta and pinguicula moctezumae plants recently. I recently moved into my apartment in Iowa from my family's house. At my family's house the plants had been in a glass covered sundeck where light had to pass through glass, now they are on my apartment deck facing east and exposed to unfiltered sunlight. My cyclosecta and moctezumae initally experenced leaf burn and dyeback of their out leaves from the light level change but kept on growing from their central growing point. Recently there has been a stretch of very hot and humid weather and these two plants are showing signs of possible stress. My moctezumae has declined to very small leaves close to the growing points and one of the three appears possibly dead. My cyclosecta has experienced little growth of late and hasn't fully recovered from its earlier leaf dyeback. Oddly my other butterworts including moranensis, laueana, ehlersiae, emarginata, and agnata haven't shown any problems so far. I keep all my plants in a water try with at least an inch of water or more in it. Aside from heat stress there my be the possibility of one or both plants may be going into dry season mode very early. I've seen what cyclosecta does when it changes from its wet season to dry season mode, however I have no idea as to what moctezumae does or if it has a dry season mode at all as this has never happened to my plant. It doesn't seem that pest are an issue, in fact the amount of bugs of any kind has been very low this year. I hope this information my be helpful and you may have a possible answer or suggestion on what I should do.
ANSWER: Hi Garrett,
It does sound like your plants are trying to go dormant. Once the larger leaves die back, keep the soil just barely damp. Usually after a few months they will start growing their larger leaves again and you can resume regular watering.
Not all Mexican butterworts go dormant, or their triggers can be different. Some do it in response to water conditions and heat, while others it has more to do with photoperiod. That could be why you're seeing it in these two an not the others.
I've also found P. moctezumae to be a fussy customer at times. They seem to have a high food demand when in active growth, and if they don't catch enough they can decline. A weak, foliar applied, orchid fertilizer can be very helpful. Spritz the leaves with it once every two weeks during active growth. Mix 1/4 tsp. per gallon of water. You can do this with all Mexican butterworts. If you can find one that is Urea-free it's better. Here's an example: http://www.larrysorchidsstore.com/servlet/the-1243/Grow-More-GREEN-Orchid/Detail
I was also going to mention to be a bit cautious of tray watering with Mexican pings. If you're using a very sandy mix you can get away with it, but keeping them in standing water at all times the way you might for Drosera or Sarracenia can often lead to rot problems. In nature these guys are not bog plants. I like to do some top watering, then leave a little water in the tray, but I won't let them sit in water for long periods. Here's a great article: http://www.carnivorousplants.org/howto/GrowingGuides/Pings_Mexican.php
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QUESTION: It appears both plants are actually dying now, all the growing points on the moctezumae are browned and the central growing point on my cyclosecta is browning as well. I brought all of my butterworts indoors to get them out of the heat since we have had constant highs in the 90's and some of the other plants my be slightly stressed from it. In the last couple day my moranensis is showing some worrying symptoms as well with some dyeback of its leaves near the base but the new leaves and growing point look fine, this could be damage from my cat uprooting it out of curiosity, heat, or to much water which may be the root of all the problems. I also drained most of the water out of the trays in case this is the cause, however I've been doing this for quite sometime and I haven't had any issues until now.
The heat is probably the biggest culprit here. Most Mexican pings are from high elevations, and are used to cooler temperatures. If you haven't been to this website yet, it's a great information source I use regularly to understand these plants better: http://www.pinguicula.org/pages/pages_principales/content.html