At this point, I’ve given up pretending I have any self-control when it comes to buying plants. I just always need more, period. And lately I’m confident enough to try a few different genera outside of my comfort zone, as you saw with my butterworts. This time, I’m trying out bladderworts (utricularia)!
Why yes, it’s planted in a tea cup. And no, it doesn’t have a drainage hole! Just a regular cup I picked up a thrift store. Before you shake me, I haven’t forgotten everything I’ve learned about carnivorous plant care! It’s true that most carnivorous plants require good drainage. Keyword being most. Bladderworts actually prefer little to no drainage!
Bladderworts are divided into three main groups: terrestrial, aquatic, and affixed aquatic. The ones I have are terrestrial, and potted (rather, tea cupped!) in two parts peat moss to one part perlite. They prefer soil that is quite wet and waterlogged. For almost every species of terrestrial bladderwort, I’ve read they enjoy being flooded with water occasionally. Distilled water, as always!
But without drainage, how do you prevent the buildup of minerals in the soil? Nearly everything I’ve read also suggests re-potting with fresh media more often than with other carnivores. Works for me, I have plenty of tea cups and will need to stay busy during the winter!
Most terrestrial bladderworts are tropical or subtropical plants, and don’t require a dormancy. They also shouldn’t be exposed to freezing temperatures. Like your Mexican butterworts and tropical sundews, they make great windowsill plants! I will be editing my carnivorous house plants article to include bladderworts very soon! Because they’re also not picky about drainage, they would likely make good plants for an open terrarium. I will probably experiment with this over winter too!
My bladderworts are currently kept near my sundews in the top, sunniest shelf of my outside mini-greenhouse. We’ve been having several days of rain here, but I’m hoping some periodic sunshine induces growth and flowering. They won’t freeze, but temperatures will go down into the 40s F. They may not do much action at all, but only time will tell!
Like with their drainage, terrestrial bladderworts don’t seem too pick about light either. It seems more sunlight and warmer temperatures will produce more flowers, but they are also perfectly happy to receive partial shade. It seems their only hard, fast requirement is keeping their soil wet.
From these photos, you’re probably thinking Okay, that just looks like moss or grass. What makes them carnivorous? That’s the super interesting part! The carnivorous parts of bladderworts are underneath the soil! They have bladders (hence the name) that trap tiny insects and other life forms that live in the soil. Dr. Barry Rice, author of Growing Carnivorous Plants and many research articles, describes best how the bladders work:
The bladder sets itself by pumping fluid out of its interior, via special bifid and quadrifid glands. As a result, the water pressure inside the bladder is lower than the surrounding water. The bladder has trap door, but it is firmly set closed by a combination of a threshold ridge at the bladder entrance and mucous as an additional sealant. Small organisms find their way to the trap entrance (it is unknown whether they just wander up to the trap, or are somehow attracted to the trap door).
Either by bumping into the door, or perhaps by touching the little hairlike organs protructing out of the trap door, they trigger the bladder. Either they simply lever the door ajar (perhaps with the mechanical advantage of the door-hairs), or the door may weaken slightly through some active process (perhaps similar to the changes in turgor pressure that makes Mimosa plants droop, or processes that occur in Dionaea?). Since the pressure in the trap is low, water rushes into the trap, carrying the animal with it. The prey has no chance to protest since it is drawn into the trap in as little as 1/30 of a second. The trapdoor swings closed again, sealing the creature inside.
Quote from The Carnivorous Plant FAQ.
Unlike nearly all other carnivorous plants, bladderworts have the least visually impressive leaves, yet the most complex method of carnivory, which we can’t even see! That is just so fascinating to me. Their flowers, though, are stunning! They’re every bit as complex and ornate as orchid flowers, and are the main reason hobbyists choose to grow them.
One terrestrial species that is easy to grow and produces THE CUTEST! flowers is utricularia sandersonii. Their flowers seriously look like white bunny rabbits suspended in midair!
My U. sandersonii are currently being shipped to me from Predatory Plants! I can’t wait to see bunny flowers blooming from their little teacups! The cuteness just might kill me.
If you’re just as susceptible to pretty flowers and cuteness as me, Predatory Plants still has U. sandersonii in stock at an awesome price! There is really no better bladderwort to start with!
Bladderworts are unassuming, and frankly unimpressive plants until you take a closer look at what’s under the surface. 😉 Just from what I’ve recently learned, I have a new-found appreciation for these little guys and now I can’t get enough! Maybe I sparked a little of that in some of you?
Til next time!