Winter Carnivore Cleanups – Terrestrial Bladderworts

Backstory: it’s January, we don’t have any distractions, and the plants need us. Therefore, it’s time to discuss methods to clean up carnivorous plants for spring. For details, go back to the beginning.

Now that you’ve mastered cleaning up after spoonleaf sundews, it’s time to move to something a bit more challenging. The current exercise involves a bladderwort, Utricularia calycifida “Mrs. Marsh”. (Fun fact: when seeing a name in quotation marks behind a plant name, this refers to the plant being a particular variety or cultivar, bred for specific characteristics. The original describer, Dr. Barry Rice, named several bladderwort cultivars after characters created by the American horror writer H.P. Lovecraft: a more common cultivar of U. calycifida is named “Asenath Waite.”) Many bladderworts have grasslike or mosslike leaves and are usually only spotted among other plants by their blooms, but U. calycifida produces wide paddle-like leaves. The good news is that U. calcyfida is an attractive workdesk companion all year around, and not just when it blooms. The bad news is that when the leaves die off, the leaves pile up instead of decomposing right away, and while this doesn’t hurt the plant, it makes an unappealing mess. The better news is that this is extremely easy to clean up.

For those unfamiliar with bladderworts, the genus Utricularia is known for the bladders growing from runners, with those runners commonly mistaken for roots. The bladders have sensory hairs atop an opening at one end, and when the sensory hairs are tripped by an animal blundering into it, it rapidly slurps in everything in the vicinity, gradually expelling trapped water and then digesting any animals caught inside. Bladderworts come in essentially three varieties: the most famous are the free-floating aquatic varieties, but one very large group, of which U. calycifida is part, grow in extremely waterlogged soil, and one group is only found atop the rocks under and around waterfalls. Aquatic bladderworts tend to have relatively huge bladders, regularly catching Daphnia water fleas and sometimes even mosquito larvae, but the terrestrial and waterfall species get their nitrogen for growth from catching nematodes and other microscopic soil organisms. Since every handful of peat in this container has literal millions of nematodes in it, the bladderwort will never run out of food, as the nematodes breed faster than the plant could ever collect them. Because of that, I refer to terrestrial bladderworts as guilt-free carnivorous plants: it’s impossible to watch them catch prey without a microscope, and all they need is light and water to produce sometimes stunning blooms.

For this exercise, the following tools or their analogues are highly recommended:

Garden mat or old towel
Isopropyl alcohol, bottle or wipes
Hand cloth or paper towels
Spray bottle filled with rainwater or distilled water
Narrow garden shears or garden scissors
Long tweezers or alligator forceps
Plastic spoon
Tamper

To start, bladderworts tend to grow all year around if given a chance (ones living in temperate climates will go dormant in winter, while tropical varieties will just keep growing), so after a while, a thick-leafed variety such as U. calycifida will get clumps of dead leaves interspersed with live ones. A general guide to carnivorous plants is “if it’s brown and dead, feel free to remove it,” but since bladderworts don’t have roots, don’t pull on the leaves if you want the rest of the plant to remain in its peat mix. Instead, cut them with your scissors, making sure not to cut or bruise surrounding live leaves.

After cutting all of the dead leaves, remove them and other detritus around the live leaves with tweezers. I use alligator forceps from American Science & Surplus to get into really narrow spaces. Dispose of the dead leaves elsewhere (as with sundews, they compost well) and check the live leaves for pests such as mites.

The next job is to use the spray bottle and the tamper, but not for what you might expect. Tamping the planting mix (usually pure milled peat moss) in a bladderwort container is a great way to damage or kill bladders and their runners. However, as a newly planted container gets established and the peat settles, a crust of dried peat can remain where the old soil level used to be. Just spraying with water and just knocking off the crust with a tamper won’t finish the job, but a combination of the two works very well. The crust won’t actually hurt the bladderworts, but it looks terrible, so take the time to remove it while you’re at it.

Some species of bladderwort bloom throughout the growing season, while others only bloom in early spring (in Texas, through mid-April), and some occasionally produce bloom spikes all through the year. It depends upon environmental conditions and upon the species as to whether or not those early bloom spikes will produce blooms, so if you feel like clipping early bloom spikes so the plants have energy for blooms later in the year, go for it.

Finished clipping and removing? Now’s the time to mist down everything, and feel free to get enthusiastic. Terrestrial bladderworts like point-blank soggy conditions, so as long as they aren’t standing for too long with water covering their leaves, a good amount of water in the container won’t hurt them.

Finally, should you want to start propagating carnivorous plants, you can’t beat bladderworts: as they take over a container, just pull a plug of plant and soil from the container, put it in another with a mix of water and pure peat, and turn on the light. Use a cooking spoon to scoop up a plug if you don’t want to get your fingers muddy and put the plug into the new container: if you did everything right, you should have new growth within a month, and new blooms within a year. Didn’t think it would be so easy to start with the largest group of carnivorous plants currently living on Earth, did you?

To be continued…

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