How to Carnivorous Plants

Carnivorous Plants Growing & Care

This page covers general growing information for carnivorous plants. For information on specific CPs see the Plant Info section.

Carnivorous plants are easy to grow, if you follow a few, simple rules

1. Wet all of the time.
2. Mineral-free water.
3. Mineral-free soil.
4. Lots of light.

Wet all of the time.

Carnivorous plants are native to bogs and similar nutrient-poor habitats.  As a consequence, the plants live in conditions that are constantly damp.  To grow healthy carnivorous plants, it is important to duplicate their habitat as closely as possible.  Keep the soil wet or at least damp all of the time.  The easiest way to do this is use the tray method.  Set the pots in a tray or saucer, and keep water in it at all times.  Pitcher plants can grow in soggy soil with the water level in the saucer as deep as 1/2 the pot, but most carnivorous plants prefer damp to wet soil, so keep the water at about 1/4 inch and refill as soon as it is nearly gone.  Water from below, by adding water to the tray, rather than watering the plant.  This will avoid washing away the sticky muscilage of the sundews and butterworts and keep from closing the flytraps with a false alarm.

Mineral-free water.

Always use mineral-free water with your carnivorous plants, such as rainwater or distilled water.  Try keeping a bucket near the downspout to collect rainwater.  Distilled water can be purchased at the grocery store, but avoid bottled drinking water.  There are simply too many minerals in it.  The condensation line from an air conditioner or heat pump is another source of mineral-free water.  Reverse-osmosis water is fine to use.  Carnivorous plants grow in nutrient poor soils.  The minerals from tap water can “over-fertilize” and “burn out” the plants.  In a pinch, tap water will work for a short while, but flush out the minerals with generous portions of rainwater, when it is available.

Mineral-free soil.

The nutrient poor soils to which the carnivorous plants have adapted are often rich in peat and sand.  This can be duplicated with a soil mixture of sphagnum peat moss and horticultural sand.  Be sure to check the peat label for sphagnum moss.  Other types will not work well.  The sand should be clean and washed.  Play box sand is great, and so is horticultural sand.  Avoid “contractor’s sand” which will contain fine dust, silt, clay and other minerals.  Never use beach sand or limestone based sand.  The salt content will harm the plants.  The ratio of the mix is not critical, 1 part peat with 1 part sand works well for most carnivorous plants.  Flytraps prefer a bit more sand, and nepenthes prefer much more peat. Use plastic pots, as terra cotta pots will leach out minerals over time and stress your plants.

Lots of light.

Carnivorous plants, as a general rule, grow best in sunny conditions.  Many do well in partial sun.  The nutrient-poor, soggy bogs provide bad conditions for most plants.  Those that do grow in the bog are usually stunted or short in height.  As a consequence, the carnivorous plant habitat tends to be open and sunny. Full sun brings out the red pigmentation of most carnivorous plants.  Many carnivorous plants grow quite well out-of-doors or indoors in a bright, sunny spot. Any windowsill, but north, will work fine. The plants also do well under artificial light with a timer set at 12-14 hours.  Fluorescent tubes designed for plant growth work better than plain bulbs.

Dormancy.

Many carnivorous plants are native to temperate climates and require a dormancy period.  This is a natural protective mechanism that allows plants to survive the harshness of winter.  Some carnivorous plants, like the sundews, form winter buds.  Others, like the Venus Flytrap and pitcher plants, form winter leaves.  Some simply drop their leaves.  Carnivorous plants will enter dormancy when winter conditions begin.  If they are not allowed to rest, they will exhaust their energy and die.  When the plants begin to show signs of dormancy, water them less.  Leave the soil only slightly damp.  Reduce the amount and the length of daylight.  Keep them cool for 3 to 6 months, depending upon their native area.  This can be done by placing them in the basement or on a frost-free porch.  A refrigerator is fine; just be careful not to freeze them.  Carnivorous plants do not require light during dormancy and darkness will not harm them.  Tropical carnivorous plants do not require dormancy.

Humidity.

Carnivorous plants grow naturally in humid bogs and swamps; therefore the growing environment should duplicate these conditions.  This can easily be accomplished by simply keeping the plants wet at all times.  A humidifier placed near the plants is a wonderful way to increase humidity.  Perhaps the easiest way to provide humidity is to grow the plants in an open terrarium.  Do not seal the plants in a tightly closed container.  This will invite fungus and mildew which could kill them.  Leave the terrarium slightly open so that a draft of air can enter.  Experiment with the size of the opening so that the plants do not either dry out, bake or become infected with fungus.

Temperature.

Most carnivorous plants will do fine in normal room temperatures.  Avoid species that require very warm or very cool temperatures.  Keep in mind that carnivorous plants are generally tolerant of temperature, and it can be varied somewhat without harmful results.  For best results, keep the plants within their optimum temperature range.

Feeding and Fertilizing.

As a general rule, do not feed or fertilize carnivorous plants.  Grown under the conditions outlined in this flyer, the plants will be able to collect enough insects on their own to do well.  Most carnivorous plants only need an insect or two a month in order to flourish.  Of course, it is fine to demonstrate the unique trapping capabilities of these plants by using a fly carefully placed with tweezers.  Never use raw meat or cheese, as large pieces will kill the traps.  Freeze-dried insects from a pet shop, or a culture of wingless fruit flies provide an excellent source of nutrition.  Carnivorous plants grown with no insect supplemental feedings will not flourish.  Be careful and do not overdo it.  Grow the plants in such a way that they have natural access to insect prey.

 

How to divide and repot Sarracenia,

by Phil Wilson

 

 The Carnivorous Plant FAQ