Proper planting?

David W. Kramer kramer.8 at
Wed May 3 08:04:38 EST 2000

>I got a 30 gallon tank and put about 1 inch of sand on the bottom and put in
>about 5-6 inches of sphugnum peat moss over it.  I have also added a screen
>on top for maintaining humidity.  I want to add venus fly traps to this
>terrarium type set up.  Question is how much water should I add? How often?
>and Do i need more peat? How much space do fly traps need? I know flytraps
>need acidic soil, is the peat naturally acidic or do I need to add
>something? Should the sand and the peat be mixed, right now the peat is just
>on top of the sand.....thanks!
>"Forgiveness is the scent a rose leaves on the heel that crushes it."

The following information is from a professional horticulturalist who has
raised many species of carnivorous plants quite successfully for about 30
years.  I've condensed this info to save space.

1.  Put about 2 inches of perlite in the bottom of the aquarium, not sand.
The sand can have impurities that damage the ecosystem.

2.  Cover the perlite with fibrous sphagnum moss (not the composted
sphagnum moss used in the garden).  The moss is sold dry and needs to be
soaked in DISTILLED WATER before placing it on top of the perlite to a
depth of about 5-6 inches, making sure there are not large air pockets in
the moss layer.  It would be good to cover the top with LIVING sphagnum
moss but be sure you don't damage a bog ecosystem if you gather it from
nature.  It's better to buy it from a supplier; most vendors of carnivorous
plants are a source of living sphagnum.  If you can't find living sphagnum,
it's possible (it's always happened for me) that some spores in the dried
fibrous moss will germinate and produce living sphagnum plants on the

3.  Before adding the sphagnum, set a small (2 inch; the same pot that the
carnivorous plant is shipped in) empty plastic pot (with drainage holes in
the bottom) on top of the perlite in one corner of the terrarium.  Pack the
sphagnum around this pot to hide it but leave the pot empty and the top
open.  This is where you will water your terrarium.  You will put water in
the pot and let it seek its own level in the terrarium.  Add water to
maintain a depth of 2-3 inches (the pot allows you to know exactly how deep
the water is) during spring and summer months then drop it down to about
1/2 inch in late autumn through winter.  I add water as needed, about once
per week.

4.  USE ONLY DISTILLED WATER in this terrarium.  Fluoride compounds,
chlorine, and miscellaneous minerals in tap water (even well water) can
damage the plants.  The moss will maintain the proper pH.  Do NOT add any

5.  Keep the terrarium in bright sunlight.  The patio is a good place in
summer.  I have had great success with a terrarium under continuous
fluorescent light.  Under those conditions the plants grow, flower, etc.
Plants like pitcher plant don't get quite as maroon in color as plants in
nature but they grow well.  Remember that bogs typically are in full sun.
They aren't the dark, dank places pictured in cartoons and movies.  If a
rainstorm floods your outdoor terrarium, just pour off the excess water.
Be sure to check the water level frequently in an outdoor terrarium as
evaporation will be greater than in an indoor terrarium.

6.  Venus fly traps require about a 4 inch diameter circle when full grown.
Pitcher plants about 5-6 inches.  Sundews about 2 inches.

For more information (varies slightly from above!) and links to other CP
sites, see
David W. Kramer, Chair
Education Committee
Botanical Society of America

Asst. Prof. of Evolution, Ecology, and Organismal Biology
Ohio State University at Mansfield
1680 University Drive
Mansfield, OH  44906-1547
Phone:  (419) 755-4344      FAX:  (419) 755-4367
e-mail:  kramer.8 at

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