Nepenthes Macrophylla
One of Sabah's iconic toothy species, Nepenthes Macrophylla grows on three mountains: Mt. Trusmadi, Sinsing, and Kaigaran. All three of these mountains are geographically quite close, with the former, Mt. Trusmadi, being the most popular mountain to climb. The species generally occupies the mossy forest below the mountain summits from 2300-2500m in elevation. Nepenthes Lowii also grows sympatrically with N. Macrophylla, but generally grows at lower elevations on the mountain. Notably, this is not the case on Mt. Sinsing, where both species grow together all the way to the summit. The natural hybrid, N. Trusmadiensis, is often found between the two species populations. There doesn't appear to be any discernable difference between the N. Macrophylla on each mountain, although the natural hybrid, N. X Trusmadiensis, is absent from Mount Trusmadi due to poaching.
Cultivation Requirements
In terms of growing, this species is not too challenging, so long as the proper conditions are provided. Like N. Villosa, younger seedlings are susceptible to crown rot until they exceed 2" in diameter. I generally recommend giving young seedlings a light dose of Physan 20 fungicide every few months to reduce the chance of rot.
Fertilizer
Nepenthes Macrophylla responds very well to nutricote pellets added to the soil. I typically add 3-4 pellets (nutricote 18-6-8 180 release) every 6 months. I would only start to do this after a new plant has hardened off to it's new conditions. Don't try feeding the pitchers with Nutricote pellets until they are atleast 2" tall! Macrophylla pitchers are quite fragile when the plant is still young. The pellets will burn the pitcher and part of the leaf.
Light
This species grows in nearly full sunlight in situ. The trees in the moss forest provide some shade, but this is negligible as the trees have almost no foliage. My seedlings receive about 10-15 DLI (mol m−2 d−1), depending on the time of year. N. Macrophylla will grow fine in shade, but the pitchers will not be nearly as red.
Temperatures
N. macrophylla is a strict highland grower. My temperatures typically range from 55-58F at night to 75-80F in the day. If N. Macrophylla experiences a heat wave, it can cause the plant to sulk for quite a while! For this reason, I try to shade the plants in the summer and provide some extra misting during particularly hot days.
Soil
While N. Macrophylla can tolerate wetter soil than N. Villosa, I have found it generally appreciates growing in well draining soil, with periods between watering to allow the soil to breathe and not become over-saturated. I plant my N. Macrophylla in a mix of 50% coco chips, 50% perlite. I have also tried 50% long fiber sphagnum, 50% perlite which also works well but has a tendency to dry out much faster. For context, I water once every four days and try to let the top soil dry out between each watering. Some growers have reported success with inorganic soil. The grower Tom Kahl strongly recommends net pots for both N. Lowii and N. Macrophylla. This allows the soil to breathe and dry out faster which is important if you tend to water more frequently. Be careful if you use overhead misting, too much water on the plant crown can cause crown rot in young seedlings, especially in winter when temperatures are cooler! When choosing pot sizes, it's important to remember N. Macrophylla has a massive root system! Ideally, I try to match the size of the pot to the diameter of the plant, or keep the pot larger to allow for future growth. Like N. Lowii, N. Macrophylla can become root-bound as the plant gets larger.
Pests
For some reason, N. Macrophylla appears more susceptible to tarsonemid mites compared to other species. I've had to help several Macrophylla growers with this pest. These type of mites are microscopic, but if the plant starts producing deformed leaves (with scars underneath) and aborted pitchers there's a pretty good chance that it's infected. The current recommended treatment is to spray with avid miticide three times (once every 3-5 days to kill the mite offspring). Afterwards, the plant should be bagged. Mites can often damage the plant's tissue, so bagging the plant helps newer growth recover (do not bag the bottom of the pot, let the soil breathe). Once the plant produces several new leaves, the bag can be slowly removed.
This guide was written by a human.