Humidity for Terrestrial Utrics

[tanukimo]

I currently have Utricularia longifolia, sandersonii, and bisquamata growing on a sunny windowsill, but the longifolia is growing really slowly. When I received it, it already have some leaves that were brown and it hasn't really grown noticeably in a few weeks. I've heard that it isn't that difficult to grow, but mine doesn't seem to be thriving. My other Utricularia seem to be doing fine, since they are continuously flowering.

I'm keeping it in a water tray with some other carnivorous plants, but I'm still afraid that my humidity isn't high enough. There isn't any air conditioning or heating on normally, and I normally move it from a south-facing window to an east-facing window in the afternoon so it gets quite a bit of direct sunlight. Is humidity really important for longifolia or terrestrial Utricularia in general?  Does anyone have tips on growing it? I've only been growing terrestrial utrics for about a month, so any help would be greatly appreciated.

Also, there are some stalks with capsules on them in both of my pots. I'm not sure what they are. They are spherical and kind of look like cleistogamous flowers, but does Utricularia longifolia produce them? They might also be moss spores. You can see some in the last picture.

[marcel]

Sandersonii and bisquamata might do reasonably well in your set up but will do better with higher humidity. Longifolia really prefers higher humidity for good preformance.

[Apoplast]

Hi Tanukimo - I agree with Marcel, though I've done best with So. African terrestrial utrics at lower humidity. Marcel is probably correct that the utrics themselves prefer higher humidity, but for me, under those conditions the plants quickly lose out to moss. So whether or not they don't do as well with the low humidity, overall they seem to compete better with the moss under those conditions.

It sounds like you are having the same problem with longafolia as I had years ago. I was getting fungal spots on the leaves, and they were turning brown. I got what seemed like counterintuitive advice to increase the humidity. It worked though. Worked for some epi utrics too!

[tanukimo]

Thanks for the quick responses marcel and Apoplast! I have a 10 gallon fish tank that I could use as a makeshift terrarium if I cover the top, so I'll try that.

[hcarlton]

Looking at your soil I can point out another problem: longifolia is occasionally terrestrial, but also often an epiphyte, and prefers very loose soils. A long fiber sphagnum mix would do a lot better for it that the peat you appear to have it in. Mine has been in an LFS/perlite mix for years in a very large pot, and has flowered once already and reached the point of being so dense in the pot that it may well break the sides if I don't thin it out.
As for humidity, all of my Utrics grow in very high greenhouse-condition humidity, and all do well under those conditions with bright light to direct sunlight, when they can get it. Also, the stalks you have with the pods on top I can almost guarantee are the cleistogamous form of U. subulata just looking at your pictures. It'll take over U. sandersonii pretty quick in some cases, though for a big species like longifolia it shouldn't be a problem.

[tanukimo]

I purchased the plants a month ago and they were grown in peat, but I've been meaning to change it since it seems like the peat is gradually leaking out of the pots through the holes every time I water them. I'll make sure to order some long-fiber sphagnum for the plants. I'm kind of curious to see what the bladders look like in the soil.
Thanks for explaining what the stalks were. I wasn't sure what they were because most of them are already dried out. I ordered subulata seeds a few weeks ago, but I guess I didn't need to.