04 Sep Slat trick: How we built a healthier habitat for our nepenthes pitcher plants

Their hardboiled, bloodthirsty reputation aside, our carnivorous pitcher plants cry out for more tender loving care than any other plant we grow.

We still haven’t been able to satisfy them. Our Nepenthes are not happy campers at the moment: Our dear Nepenthes x ventrata hasn’t produced pitchers since 2011. (Contrast this with the moment it literally walked into our lives in the arms of two close friends, a showstopping birthday gift lousy with its distinctive red and green “monkey cups.” But it did flower recently.) Our Nepenthes ventricosa also quit producing its king-size pitchers last winter. Absent a serious intervention, 2013 could go down in history as the Year of the Pitcherless Pitcher Plants.

Our first Nepenthes x ventrata in better days, in October 2009. It has since lost most of its vigor.

Our first Nepenthes ‘Miranda,’ which we brought into our garden last year, when its jumbo pitchers were in good form.

Earlier this summer, we decided to remodel the carnivorous section of the garden in hopes of bringing these guys back to life. Last week, we completed the project.

Here’s what happened:

According to our online sources, many nepenthes will stop producing pitchers when humidity levels drop too low. We keep our plants outside here in coastal San Diego, where we average around 70 percent humidity throughout the year, in a corner of the garden where RB built our outdoor shower. (A must if you live near the beach. Not a grain of sand has crossed our threshold in years.) We’re not humid, but we’re not desert-dry either. Both our plants are highland Nepenthes species, which don’t require as much humidity as their lowland cousins which thrive at around 75 percent.

Our lackluster Nepenthes x ventrata (left) and Nepenthes ventricosa (right) are no longer producing pitchers.

The neatly trimmed, 20-foot high ficus behind our fence blocks all morning light, after which the area gets slammed with direct afternoon sun, which we suspect is responsible for drying out our plants’ pitchers, leaves and soil. We knew that we also needed to trim back our vines to encourage new growth. (As heartbreaking as it is to trim back eight feet of vine growth from our original ventrata.)

A trip last July to Home Depot — which stocks N. x ventrata and N. ventricosa — got us brainstorming ways to save our precious, predatory neps. We interrogated a staffer.

“Have you tried to grow nepenthes yourself?” we asked.

“Yes,” said the gentleman unboxing a ventricosa.

“Have you had a lot of luck? Any advice?”

“Mine didn’t pitcher for a year until I cut back the ventricosa to the base a couple of months ago,” he said, “and they took off and started popping out pitchers left and right. Also, I stopped using distilled water, and keep the soil moist with tap water with no problems.”

Hmmmmmm. Despite our skepticism about the no-distilled-water tip (which flies in the face of every bit of nepenthes advice we’ve ever gotten), we  took home a new N. ventricosa, with “waisted” pitchers two inches wide by nine inches long, and a new N. x ventrata. RB was stopped five times by curious onlookers on the way to his car.

Nepenthes x ventrata were plentiful this year at the Home Depots of San Diego.

Now that we’d doubled our pitcher plant collection, we resolved to transform our “Carnivore Corner” into the healthiest habitat it could be, an environment that would maintain the pitchers on our new plants and hopefully return the wasp-trapping glory days to our older nepenthes. (Not to be confused with the boutique/gallery of the same name in Japan and New York.)

Our Carnivore Corner Design Challenges:

1. We needed 50 percent shade or dappled sunlight throughout the day (according to pitcherplant.com). Our nepenthes plants were receiving direct afternoon sun from above, and had dry leaves and absent pitchers as a result.

2. Hide the reed fence! A very similar goal to our vertical shade garden project: Even if we were able to replace it, any new reed fencing would likely have been an unattractive yellow bamboo. Enough said.

3. Incorporate a clean, modern design. We’ll let the nepenthes vines provide the unruliness.

4. Install an overhead cover that would allow us to keep RB’s pendant cage fan downlights in place.

5. Maintain and improve the functionality of the outdoor shower.

6. Provide a more regular watering regimen.

Our Solutions:

A slatted design would provide the clean modern design (Challenge 3) that we were looking for. We even went all out and installed a floor for the area! This really made the corner look like its own discrete outdoor room: RB constructed the flooring, wall (2) and overhead slats (4) out of 7-1/2″ wide redwood fencing using a planer, and a tablesaw to convert the redwood fencing into floorboards and 2-1/4″ wide slats.

The horizontal slats were stapled to vertical ties and painted (um, three times) until we settled on the final color. We also installed a soap dish, which, along with the floor, elevates the outdoor shower experience. (5)

A slotted soap dish and floor were made from redwood fencing and improved the functionality of the outdoor shower. The flooring helps separate and distinguish this area of the garden.

Newly acquired carnivorous plants (on left) await their new home. Their previous habitat did not provide enough sun filtration. Most nepenthes species prefer dappled sunlight or 50 percent sun.

Slatted wall ready for fit-up.

Here’s the first color we tried, a Behr waterproofing wood finish in a transparent redwood color. Unfortunately, the color seemed to disappear at night.

The second color we tried was a Behr exterior wood stain, a solid color in ‘Natural Redwood.’ This color just didn’t jibe with the varnished redwood flooring. It didn’t feel warm enough.

Ahhh, the final and favorite color: Behr exterior stain, a solid color in ‘Redwood.’ It has the warmth and richness we’re looking for, and the color still crackles after hours.

The redwood floor section is glued from the underside and the design is fully removable. Redwood is a soft wood, so screws were not used as they would likely split the wood during drilling.

The new overhead slat design provides dappled sunlight during the intense afternoon sun.

The overhead is installed so that the pendant lamp chains hang through the slats (4). The slant of the ceiling is hinged on an aluminum bar across the top back of the wall. The overhead slat structure rests by gravity on the back hinge making it fully removable and adjustable.

Even after the wall and overhead slats were fully assembled, the late afternoon sun still had a direct line to the lower portions of the vines. To soften the sun’s rays (1) on the lower portion of the habitat, RB installed a tinted Lexan removable visor option.

It’s like sunglasses for plants! This polycarbonate shade also compliments the nearby acrylic garden pond. Lexan has outstanding mechanical, optical and thermal properties, which makes it ideal for this installation.

RB picked up this 4-foot-by-8-foot sheet of Lexan at his go-to surplus store back in February for $40, sensing that he would eventually find a use for it. The harsh direct afternoon sun can be seen on the carnivore corner behind the arbor.

The polycarbonate visor shields the plants from direct sun…

…and also adds nighttime interest. The shade is on two hooks which makes it easily removable when we don’t want to be shady.

Only when we’ve done right by our neps will we feel worthy of our long-desired trip to bug trap mecca California Carnivores in Sebastopol, CA. And we’re getting close. Finally, to ensure better irrigation for our plants (6), we installed a mister off our timed irrigation system to regularly mist the entire corner every other day for a few minutes.

We’ll also be sure to water the soil a bit more, to see if we can get this pitcher party started again!

—TH

Makeover complete!

We installed a mister from our drip irrigation system to supply mist from the top of the habitat.