Winter Carnivore Cleanups – Nepenthes x ventrata

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.

All carnivorous plants have their distinctive charms, but Nepenthes pitcher plants have a lot that they don’t share with anything else. It’s possible to hyperfocus on Venus flytrap lobes or sundew tentacles and gloss over the rest of the plant, but Nepenthes requires integrated appreciation. Even with seedlings, there’s that balance between traps and the leaves from which they dangle, and how many other carnivores produce a completely different trap as they continue their life cycle? For that matter, how many other carnivores (easily accessible ones, anyway) vine and climb? Starting a Nepenthes collection is a special reward, mostly because of the wide variety of coloration, trap shape, and trap function to be found with widely available species, and the wonder just keeps going as they grow. That wonder just expands with the ever-expanding list of hybrids and cultivars available from breeders that didn’t exist two decades ago, because some of the people getting these hybrids now are going to be the first people on the planet to see exactly what these plants are going to look like when they’re fully developed.

Nepenthes x ventrata is regularly derided as a “common” Nepenthes hybrid, mostly because it’s so readily available in cultivation. A hybrid of Nepenthes ventricosa and Nepenthes alata (and is regularly mislabeled as “Alata”), N. ventrata is an excellent beginner plant because of its enthusiastic growth and tolerance over a wide range of temperature and humidity. The traps remain relatively small compared to some other species and hybrids, with a bottle shape with a green base and bright red neck on both lower and upper traps. For those wanting to incorporate a carnivorous plant into a vivarium, N. ventrata is an excellent choice: tree frogs love camping in the pitchers, the leaves give shelter for lizards and dart frogs, and N. ventrata‘s enthusiastic vining offers excellent climbing opportunities for chameleons, anoles, and geckos. Give it enough humidity and light, and you’ll soon see multiple vines and new growing points coming off the roots, and the only real issue with N. ventrata is a need for regular trimming of the thick tangle of vines from a contented plant.

That regular trimming is, in fact, an issue, especially in smaller containers and enclosures. The featured container was one that fell off the radar after March 2020: it’s currently seriously overgrown, and either needs to be cut back or put into a larger enclosure (ahem). Either way, it needs to be cleaned up and checked over, and January is a perfect time to do this

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

At this point, it’s time to address additional tools that may or may not be necessary when working with Nepenthes. At a certain stage in each plant’s life cycle, the central growth point starts to stretch and vine, and it’s at this point that the plant starts producing its distinctive upper traps well off the ground. Those vines can be extremely tough and strong, to the point of breaking standard garden scissors and bypass pruners. (I once had a very old and tough Nepenthes vine that broke a pair of bonsai shears as I was attempting to cut it, and I finally had to cut the vine with a Dremel tool.) Because of that strength, two items from both medicine and bonsai might be a valuable addition to the toolkit for those planning to move further into Nepenthes husbandry. Of the two tools above, the one on the left is a bone shear picked up at an estate sale: not only does it have a long shaft for reaching deep into leaf clusters, but its blades are strong and sharp enough to cut through most Nepenthes vines. For the really tough ones, though, comes the bonsai concave cutter, and if it’s not enough for a Nepenthes vine, time to get the Dremel tool or maybe an angle grinder.

Opening up the one-gallon (3.7L) jar, things look much worse than they actually are. The main growing point on the plant started to vine, found itself caught in a depression in the center of the jar lid, and twisted around a few times before it died. However, it has at least one other growing point, and probably lots of other surprises once the dead leaves are cleared out.

A fairly safe standard for trimming carnivorous plants, and many plants in general, is “if it’s brown and dead, cut it off.” Generally, if a leaf or stem dies, it’s not coming back (an exception could be made for dying butterwort leaves), so there’s no shame nor risk in cutting it free. The central vine is definitely dead, so let’s cut it off and all of the easily reachable dead leaves to get a better view of the interior.

(Note: when trimming Nepenthes leaves or stems, try to cuttings away from the rest of your Nepenthes collection as soon as possible. Composting the chunks is fine, and burning is an extreme response but understandable, but get them outside and away. This minimizes the chance of fungus spores or insect pests migrating from the pieces to healthy plants.)

Right here is one reason to take things slowly and methodically when trimming a Nepenthes. At the edge of the still-living parts of the main Nepenthes vine is a new growing point: this leaf probably won’t grow any further on its own, but it promises a whole new vine growing from the side if given enough time. This is encouraging, but let’s clean things a bit further before making any decisions.

Clipping out the dead vine and various dead or older leaves, and we have a much better view of the rest of the plant. In addition to the vine, we have not one but two offshoots growing from the roots. Give this clump a chance to recuperate from major surgery, and these could be separated from the main plant and repotted on their own. Otherwise, everything is looking good, with no signs of fungus, insect pests such as scale, or other reasons to quit the cleanup and start fresh.

At this point, the trimmed plant needs a command decision: do you try to rehabilitate the original vine, or do you emphasize the new plantlets? Sorry, vine: you’re getting cut from the team. If the vine had some special structure to it, or if it showed any special characteristics that would justify propagating it, then there’s either leaving it alone or cutting it and treating it with rooting hormone to grow it as a new plant, but there’s no reason in this case. Cutting the vine will revitalize the plantlets, not just because of the increase of light but also because the plantlets will no longer be transferring nutrients to the parent to the level they had been.

All right. NOW we’re getting somewhere. These two plantlets are going to stay small for a little while longer, so they’ll stay together while they recover from surgery. If they get out of control, the two options are either to cut off the growing points in the center or to move them to a larger enclosure (again, ahem), but for now, they’re not an issue. Gently tamp down the sphagnum growing alongside the Nepenthes with a finger or a tamper, and this stage is finished.

The next step in cleanup is the glass. Because Nepenthes get over half of their moisture requirements from water they absorb through their leaves, they need to be kept in as humid an atmosphere as possible. (This is why the Nepenthes hanging baskets sold in garden centers and at flea markets don’t do so well when kept outside in Dallas. If this were Houston, the average humidity is so high that they only need to be brought inside during the winter, but Dallas has both such low humidity in summer and such wildly variable humidity throughout a typical day that those hanging baskets dry out too rapidly unless kept in a greenhouse, and the plants that don’t die just can’t get enough moisture to produce pitchers.) High humidity, though, usually leads to algae films growing over the inside of the container, and that should be cleaned off. A little bit of glass cleaner on a paper towel (please note: spray the glass cleaner on the paper towel before wiping and NOT on the glass directly), and the slime comes right off.

All done with the wipedown? Now the cleanup is done for now. The peat inside the container is a little too wet after spraying everything down, but leaving the lid cracked a little for a few days will take care of that. With the next project, we’ll clean up a much larger enclosure than this, and THAT is going to be an adventure.

To be continued…

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