19 Oct

How To Water Carnivorous Plants

How To Water Carnivorous Plants

All carnivorous plants need water but to varying degrees. Many sundews, flytraps, and American pitcher plants thrive in bog-like conditions while most Mexican Pinguicula are happy in a seasonal desert-like environment. No matter how wet or dry a plant prefers conditions though, one way to water carnivorous plants safely and effectively at home is to water them using reverse osmosis.


Reverse osmosis using a semipermeable membrane

Reverse osmosis is the process of purifying water using a semipermeable membrane to filter out salts and chemicals that can be harmful to carnivorous plants. The easiest way to water plants using reverse osmosis is with the tray method.


How To Water Carnivorous Plants Using The Tray Method:

  1. Partially fill a tray or saucer with water.
  2. Using a pot with drainage holes in the bottom, place the potted plant in the tray so the water can wick up through the holes.
  3. Refill the tray or saucer when it runs almost dry or as needed depending on the type of carnivorous plant you are growing.

Water TraySaucer partially filled with water

Pot with HolesPot with drainage holes

Tray Method - Watering

Watering a Venus Flytrap using the Tray Method

With this method, the soil acts as the semipermeable membrane and filters out unwanted salts and chemicals, delivering cleaner water to the plant’s roots. Pretty simple right? It’s important to note though; while this method helps a great deal to filter out unwanted contaminates, it won’t filter out everything. For this reason, using cleaner sources to begin with like rain or distilled water along with cleaning trays regularly to prevent salt and chemical buildup is still a good idea.


Secondary Benefits of the Tray Method

The tray method also has some other benefits like preventing media erosion and for bog species, providing a consistent supply of water to the plant’s roots without having to water the plant everyday. To an extent, the tray method can also help keep water away from plant crowns; an area often susceptible to disease and rot if too much water is present.

Pinguicula - Brown Heart Disease

A Pinguicula lost to Browning Heart Disease from too much water near the crown


Other Methods

As with most things, there’s usually more than one way to do something. Do you have a favorite method for watering your carnivorous plants other than the tray method? What are some of its benefits? Please comment below and tell us, we’d love to hear about it!

22 Jun

Watering Carnivorous Plants

Not all water is the same

Tap water

Using tap water for carnivorous plants in many cases isn’t a good idea. Tap water contains salts and chemicals (Also called Total Dissolved Solids or TDS). While harmless to humans, some of these salts and chemicals can have detrimental effects on sensitive carnivorous plants, causing root burn, leaf browning, wilting and eventual death of the plant.

The amount of salts and chemicals in tap water is measured by parts per million (PPM). The PPM of tap water can vary depending on location but often falls between 100 and 400. Most carnivorous plants can tolerate a PPM range anywhere from 50 to 140, but the lower the number the better. If you are considering using tap water for your plants, buy a TDS Meter to check your PPM first. It’s also important to note that if your PPM is in the upper end of the “safe” range, flushing soil and trays regularly with fresh water is a good idea to help prevent mineral buildup.


TDS in parts per million (PPM)

Source: “What is TDS?” HM Digital


Rain and stream water

Rain or stream water can be good and inexpensive alternatives to use for carnivorous plants, if the plants are outdoors. Using rain or stream water can have downsides for indoor plants though. The main ones being possible contaminants like algae, bacteria, fungus and plant pests.  Yes, even rainwater may contain small amounts of these! Exposing indoor plants to these contaminants is risky because there isn’t a balanced ecosystem like the one outside to keep various outbreaks at bay.

In addition, rain water tends to be acidic with a pH of around 5.6 due to interacting with carbon dioxide in the air. This may or may not be harmful to your plants but is still something to think about.

Rain Water


Distilled water

Using distilled water is the safest route when watering indoor carnivorous plants. The water is free from salts and chemicals and the steaming process kills organisms that may be present as well. You can purchase distilled water at the store or distill it yourself. We have found a basic household distiller like this one works well for the average hobbyist. It can produce up to 6 gallons per day. Using distilled water in combination with the tray method of watering is a good practice if you want healthy indoor carnivorous plants.

Distilled Water


And don’t do this…please.

A common misconception about distilling water is to leave tap water in a container overnight to give minerals and chemicals a chance to “evaporate”…there’s a problem with this method though, it doesn’t work! The only thing that evaporates is the water leaving what remains even more salty. Only use this method of “distilling”  if you want to kill your carnivorous plants.

Annoyed Cat

This cat doesn’t think it’s a good idea either


Who knew there were so many types of water

Hopefully this article helps you determine what type of water you will use for your carnivorous plants based on your location and growing environment. If you have questions, please feel free to leave them in the comments. Thanks for reading!