Feast Your Eyes, as they Feast on Flies: The Mesmerizing Nepenthes Plant

Carnivorous plants sit quietly, creepily waiting to trap and slowly digest unsuspecting insects. One of the best-known is a fun plant called Monkey Cups, or Asian Pitcher Plant (Nepenthes) that can be grown in a hanging pot as a houseplant.  

Most species of Monkey Cups are tropical vines that climb up trees, but some species stay on the ground. They grow in various habitats, from grasslands to steamy rainforests in Southeast Asia, Malaysia, Indonesia, Papua New Guinea, the Philippines, and northern Australia.

What Do They Look Like?

Monkey Cups have strap-like, ordinary-looking leaves, but unlike other plants, they have a strong midvein extending beyond their leaves for several inches. The ends of the midveins develop into upright pitchers to trap insect prey with umbrella-like lids to protect the insides of the pitchers from rain.

The lip surrounding the top of the pitcher produces nectar to attract insects and is slippery, so they can’t get a foothold to crawl or fly away. When they fall in, there are stiff, downward-pointing hairs on the insides of the pitchers to prevent them from crawling out.

They tire and drown in the pool of liquid enzymes at the bottom of the pitcher and are slowly digested. Creepy? You bet!

Why Do They Trap Insects?

Carnivorous plants need the right light, water, and temperatures, just like other plants, to make their food by photosynthesis. But they also need an extra boost of nutrition from an outside source so they can survive in boggy, poor soil.

Photosynthesis produces sugar that the plant can use immediately or store as starch. What it can’t produce are essential nutrients like nitrogen, phosphorus, potassium, calcium, magnesium, and trace elements that are found in rich soil and fertilizer. These nutrients and trace elements are crucial for photosynthesis to run and, therefore, for the plant’s growth and survival.

Carnivorous plants have evolved a workaround for obtaining these minerals and living where other plants can’t — ways to trap and digest insects and small animals. They do it in one of three ways depending on the type of carnivorous plant — active traps like Venus Flytraps, passive traps like Pitcher Plants, or sticky traps like Sundews.

Monkey Cups use the passive trap method of capturing their prey. They attract insects with the sweet-smelling nectar just below the rim of the pitcher, and as the bugs bend down to drink the nectar, in they go!

Fortunately, these fascinating plants make great houseplants and are pretty easy to grow. You just have to give them the proper care and pay attention to some specifics for them to thrive.

Care of Your Monkey Cups Plant

The combination of bright light, the right amount and kind of water, and type of soil will keep your plant healthy.

Light

Monkey Cups need a lot of light. About four to five hours of direct sunlight is best, with bright indirect light the rest of the day. Set them in an unobstructed west- or south-facing window, and they should be fine.

If you bring your plants outdoors in the summer, set them in bright shade, such as the dappled sunlight under a tree, and keep them out of harsh wind.

Temperature & Humidity

Average household temperatures (68 to 72 degrees F) are perfect for Monkey Cups. They don’t like extremes in temperatures or hot or cold drafts and may refuse to grow pitchers in unfavorable temperatures. 

Monkey Cups prefer humidity in the 60 to 80% range, but they are adaptable. Light, temperature, and soil type are much more important to their growth, so concentrate more on these factors than humidity.

Soil

Carnivorous plants can live in a wide variety of soil types as long as they’re low in nutrition and have good drainage. You can use commercial carnivorous plant soil, or you can make your own, which is more cost-effective.

One part dried sphagnum moss that has been hydrated mixed with one part perlite works well, and you can also include some orchid bark or pumice for extra drainage.

Pot

The most important feature your pot must have is a drainage hole in the bottom so that water doesn’t collect and rot the roots. Monkey Cups can grow happily in a small pot because they have small, delicate roots and only need to be repotted when they outgrow their containers.

Water

These plants love evenly moist soil that is never waterlogged. When the top layer of soil is dry, water from the top and let it run through the pot and out the drainage hole, remembering to empty the excess water from the dish under the pot.

You can use distilled or tap water for your plant. Unlike most other carnivorous plants, Monkey Cups can handle tap water as long as you flush the soil twice a month with distilled water to free it from a buildup of minerals. 

Nourishing

The process of photosynthesis from light, water, and carbon dioxide is what makes food energy for your plant. Insects are the fertilizer that provides the essential minerals and micronutrients to the plant, so they don’t need to be fed that much or too frequently.

Your plant will attract insects on its own, but if it needs help, catch and feed it one insect per pitcher per week. And insects only, please! Never feed it meat, such as beef, pork, chicken, turkey, etc., that it can’t digest.

Concerns

Nepenthes Gaya plant in pot
Nepenthes Gaya

Even though Monkey Cups are not difficult plants to grow, less-than-ideal conditions can cause problems, like pitchers turning brown and falling off or the plant refusing to grow pitchers.  

Pitchers have a life cycle of about three months, and under optimal conditions, a new one will grow to replace it after it has died. But low light, dry soil, overly wet soil, environmental changes, and winter can all cause pitchers to drop and only regrow once the problems are remedied.

Your plant needs to have plenty of light all year round to keep it photosynthesizing since insufficient light can cause it to drop its pitchers and not grow new ones. Keep it happy by setting it in a sunny window during the spring and summer and supplementing the low sunlight in the fall and winter with artificial lights.

Dry soil will quickly cause the pitchers to drop, and soggy soil that isn’t draining will, too, and also cause root rot. The soil needs to be evenly moist with excellent drainage for the plant to keep producing pitchers. Feel the top of the soil to see if it is still moist or if you need to water it rather than watering it on a schedule.

Any environmental change, like repotting or a change in location or temperature, can cause pitchers to drop. But once the plant is comfortable again and conditions are agreeable, it will continue to grow new pitchers.

When the plant’s growth is slowing down during the winter, it’s not unusual for pitchers to drop. Then, if conditions are right, it will continue to grow new ones in the spring.

Author & Editor | + posts

Nancy has been a plant person from an early age. That interest blossomed into a bachelor’s in biology from Elmira College and a master’s degree in horticulture and communications from the University of Kentucky. Nancy worked in plant taxonomy at the University of Florida and the L. H. Bailey Hortorium at Cornell University, and wrote and edited gardening books at Rodale Press in Emmaus, PA. Her interests are plant identification, gardening, hiking, and reading.