Carnivorous Plants/Poor growth in Pinguicula gigantea
QUESTION: Hello! I've had this P. gigantea since mid-summer, and in this time it has shown little growth. This is not to say that it hasn't grown at all, but it sheds leaves at roughly the same rate it grows them and has yet to form a proper rosette. There was a period of overwatering a few months ago which has since been corrected. In addition I have repotted it in a 3 inch plastic pot in a light, airy mix of peat, sand, and pumice.
To start, I am located in Maine. The plant is grown in a window with western exposure. It grows among a number of other plants. I decide when to water by the weight of the pot, and I do top water with distilled water. Care is taken not to wet the crown. It catches relatively little prey, but the occasional fungus gnat is taken as prey.
Is P. gigantea a finicky plant? Also, I have heard of using dolomitic lime to achieve a basic pH for pinguicula media. Do you have knowledge or experience regarding this?
Thank you for your time!
ANSWER: Hi Campbell,
It sounds like overall your growing conditions are good. Here's two things that will help.
First, what you've heard about lime in the media is correct. We've started adding lime to the media of Mexican butterworts, and we've seen some dramatic results. Use the same soil mix you're currently using, but add 1 tablespoon of dolomite lime powder to each cup of soil. It seems like a lot, but many of these plants grow in gypsum or limestone in nature. Use regular powdered dolomite lime, not the prilled stuff. It's fairly easy to find at garden centers.
Second, try feeding the plant more. You can do that one of two ways. One way is to use something like re-hydrated blood worms (fish food), or thawed, frozen blood worms. I've also taken a high-protein flake fish food and sprinkled a little on the leaves, then put a drop of water or two on them to get them wet. Usually the butterwort will start secreting enzymes.
The less messy way to feed them is to use a foliar fertilizer. Use an orchid fertilizer mixed to 1/4 strength, and lightly spray the leaves. Do this once a week.
If you do these things you should see a dramatic increase in growth. P. gigantea will have a period of dormancy in late winter, so don't be alarmed when that happens. Most of the larger leaves will die, then you'll see a tight rosette of leaves for a few months. When that happens, just keep the soil barely damp. Resume more water when you see the plant trying to make bigger leaves again.
---------- FOLLOW-UP ----------
QUESTION: I just wanted to ask a quick follow-up about which orchid fertilizer would be best and if the one I have is safe if it isn't ideal. The orchid fertilizer I have on hand is 30-10-10 with 27% urea. It wasn't quite right for my nepenthes so i didn't use it again. Is this fine or is there a better fertilizer for pinguicula?
Thank you for your time!
You might test it on one leaf to see how it responds. Mexican Pings are notorious for having sensitive leaves. If you put it on one, and you don't see any burn, you're probably fine. If you have the Urea-free fertilizer, that is definitely better.