Growing Guide: Terrestrial Utricularia

Utricularia pubescens
Google's GIFification of my photos

I had to share Google's "auto-awesome" of a series of photos I took of Utriculatia pubescens in flower in my generic guide to growing terrestrial Utricularia, if only because it's slightly creepy. I was actually inspired to do this post by Devon's post on terrestrial Utricularia last month. (By the way, his blog is awesome, so you should definitely read it).

Utricularia sandersonii
"The Angry Bunny"

Headache inducing GIFs aside, I want to focus not on Orchioides section Utricularia, as I have done previously with Utricularia calycifida and Utricularia 'Jitka', but on the more run-of-the-mill terrestrial Utricularia, since I have quite a few of them. I guess the major difference I see between Orchioides and regular terrestrials is in the potting medium. Instead of live sphagnum/long-fiber sphagnum, I typically use a mix of 1:1 milled sphagnum:perlite, i.e. the "typical" carnivorous plant mix.

Utricularia dichotoma (bottom)
Utricularia fulva (top)

Some terrestrials, such as Utricularia livida or Utricularia dichotoma are very good at spreading rapidly. Put a tiny portion in a pot and in a few months it will have completely carpeted the pot with its little leaves. If you're lucky, you'll also see an abundance of flowers, however, not all species flower constantly. (In my experience, some variants of U. livida flower constantly, while others rarely flower).

Utricularia prehensilis

I should also note that I grow all my terrestrial Utricularia in a terrarium with high humidity, right next to my Nepenthes. I'm not sure that a terrarium is necessary, but based on their growth rates, I think that they appreciate the humidity.

Additionally, I've found that Maxsea Grow 16-16-16 Water Soluble Seaweed Plant Food Fertilizer sprayed foliarly is fantastic for promoting growth. Several times, I've sprayed my plants, not looked at them for a few days, and come back to see explosive growth.

Here's a handy tip sheet from my experiences:

Media: A mix of 1:1: milled sphagnum to perlite works well. Sand can be substituted for perlite. If this mix does not seem to be keeping your plants in good health, I would recommend trying long-fiber sphagnum as a next alternative. Different plants have different temperaments.
Moisture: Keep wet. I generally use 2.5" pots, which are fairly deep, but I use shorter pots when available. Many growers keep their terrestrial Utrics submerged. My concern with doing that is algae growth, so I generally do not. I have begun experimenting, however, to see if such treatment would work to induce flowering in plants like the notoriously difficult to flower, Utricularia fulva. I also think that, because my plants are in a terrarium, the high humidity offsets, to some degree, whatever need they have for higher moisture content.
Pot Size: I use whatever pots are available, as most will be more than happy to fill a pot to the brim, but I try to keep them to 2.5" pots where possible, if only to save space.
Feeding: Maxsea Grow 16-16-16 Water Soluble Seaweed Plant Food Fertilizer applied foliarly is fantastic! It's difficult to introduce terrestrial food for the Utrics to eat without compromising your media, so I generally rely on Maxsea to augment their diet.
Temperature: I never let my terrestrial Utrics drop below freezing, and, generally, I've found them to like the Nepenthes environment, so they live among the Nepenthes year round.
Dormancy: There's no real dormancy period for most terrestrial Utricularia, even most of the annuals can be induced into perennial status by keeping them in fairly consistent temperatures and water amounts. I will add that, for most species, it seems that there is a yearly flowering period induced by something - perhaps day length, though most of mine started flowering before I changed the day length for my artificial lights (the limited sunlight they receive, however, was changing). For instance, my U. sandersonii, U. prehensilis, and U. pubescens all flowered in the spring, whereas one clone of U. livida has been flowering constantly since a couple months after I bought it. None of them had experienced any real changes, so I'm not sure what induces flowering.
Propagation: Technically, the tiny, tiny seeds can be sewn, but they have a very short shelf-life, so, if not sewn immediately, they probably aren't viable. And, frankly, those seeds are nearly impossible to see. Many are smaller than Drosera seeds! My recommendation for propagation is to let the plant grow and then divide it. It's always easier to start off with a growing chunk than seeds.