How to Water Carnivorous Plants Properly
If I had to guess why most carnivorous plants die in their first year, I wouldn't say light or soil. I'd say water. Either it's the wrong kind of water, or it's the right water delivered the wrong way for that plant. The good news is that once you get it right, watering becomes the easiest part of the whole hobby. Here's exactly how I do it after more than 30 years of growing.
Rule One: Only Pure Water
Carnivorous plants evolved in places with almost no dissolved minerals, and their roots can't handle what comes out of most faucets. Over time those minerals build up in the soil and burn the roots.
- Safe: distilled water, rainwater, or reverse osmosis water.
- Avoid: tap water, bottled drinking water, spring water, well water, and softened water.
A cheap TDS meter takes the guesswork out. Under 50 ppm is acceptable, under 20 is ideal. Most tap water runs well above that. More on tap water here.
The Tray Method, and When Not to Use It
For bog plants, the tray method is what I use across the whole nursery. Set the pot in a shallow tray with an inch or two of pure water and let the plant pull it up from the bottom. Refill before the tray goes completely dry. It keeps the soil evenly moist without drowning the roots, and a tall pot like my 3.5 by 5 inch deep pot gives the roots room to run down toward the water.
But not every carnivorous plant is a bog plant, and this is where a lot of people go wrong. Here's how I water each group:
Venus Flytraps, Sarracenia, and Most Sundews
Tray method, all growing season. These want consistently wet feet. Venus flytraps, Sarracenia, and sundews like Drosera capensis are the easiest plants in the hobby to water once they're sitting in a tray.
Nepenthes
Water from the top and let it drain. Keep the mix moist but airy, and don't leave the pot sitting in standing water. Tropical pitcher plants like humidity, not soggy roots. Shop Nepenthes.
Mexican Pinguicula
These are the exception people miss. In summer a shallow tray is fine, but in winter most Mexican butterworts switch to small, succulent leaves and want to be kept much drier. Let the mix dry down between waterings in that season. Shop Pinguicula.
Heliamphora
Top water often with cool, pure water, and keep humidity high. They come from rainy tepui summits and like a steady flush of fresh water more than a stagnant tray. Shop Heliamphora.
Sarracenia x Leah Wilkerson, a tray plant — from $55
Pinguicula emarginata — from $18
How Often to Water
There's no magic schedule. For tray plants, check the tray every day or two and top it up when it gets low. In a hot Colorado summer, that might be daily. In a cool basement under lights, maybe twice a week. Consistency matters much more than any number on a calendar.
Adjusting for Winter
During dormancy, flytraps and Sarracenia still want damp soil, just not a full tray. I keep the tray shallower and let it go dry for a day before refilling. The plant isn't using much water while it's resting, and cold, sopping soil invites rot. More on dormancy here.
How to Tell Something's Off
- Crispy, dry leaves and stalled growth: the plant is drying out between waterings.
- Soft, yellowing growth and a sour smell from the pot: too wet for that plant, or poor drainage. Common with Nepenthes and winter pings.
- Slow blackening and decline even though you're doing everything right: almost always the water source. Test it.
If a plant is already in rough shape, start with a fresh pot of clean peat perlite mix and pure water. Here's my full revival method.
What I Use
Easy Plants to Water Right
If you want plants that are hard to get wrong once they're in a tray, start here. All in stock now, or browse the beginner collection.
Pure Water, the Right Way for Each Plant
Get the water source right first, then match the method to the plant: trays for bog plants, top watering and drainage for Nepenthes and Heliamphora, and a drier winter for Mexican butterworts. Do that, and watering stops being something you worry about.
Happy Growing
Jeremiah Harris
Jeremiahsplants.com