Very Humid Terrarium............mistake?

Last night I put together a terrarium with a Hypoestes and an Arrow Head plant. As the pictures shows I used a layer of stones for draining, the my soil and planted the plants added some Deer Moss and some small pebbles and a little Fairy. When I awoke this morning the terrarium class was very moist on the inside, did I add too much water? Not enough stones? maybe too much moss? I did take the cover off to let it dry up a bit. The plants seem ok so far.
very humid terrarium mistake, gardening, terrarium
very humid terrarium mistake, gardening, terrarium
very humid terrarium mistake, gardening, terrarium
  10 answers
  • Barb Rosen Barb Rosen on Apr 24, 2014
    When there is condensation, it is a good idea to take the lid off and let it "breathe". Many plants will mildew, mold or start to fail if there is too much moisture. Very pretty terrarium!
  • Kristy Kristy on Apr 24, 2014
    Thank youo for the compliment! I did take the top off and the condensation dissipated. How do I know when to put the top back on?
    • Barb Rosen Barb Rosen on Apr 25, 2014
      @Kristy ~ put it on or leave it off - just keep an eye when the lid is on, if condensation occurs, take the lid off again. Be careful not to overwater - that is the death of most terrariums!
  • Bev Kent Bev Kent on Apr 25, 2014
    I wouldn't put the top back on, looks prettier without. beware arrow head can grow very large
  • Kristy Kristy on Apr 25, 2014
    Looks like its going to be an on again off again kinda Would this stop if I had used a layer of charcoal?
    • Nancy Hinds Nancy Hinds on Apr 25, 2014
      @Kristy No, charcoal would not make the moisture stop, but it would keep the sitting water 'sweet'. The lid does need to be lifted after watering to dissipate the excess water. Try to just mist the plants lightly for their watering. You will get used to the watering schedule by the humidity in the bowl. It will also keep the rocks in place also the soil under the rock. Keep the Hypoestes away from the sides of the glass bowl, so it won't rot. Use long scissors to trim leaves every so often. Definitely watch the height of the Arrowhead. When it reaches the lid height- replace with a more compact or slow growing plant.
  • Carole Carole on Apr 25, 2014
    I have heard you need to put some charcoal in there to assist with moisture and to stop it going stagnant or mouldy.
  • Kristy Kristy on Apr 25, 2014
    I would love to and I have been told its cheap also, but what kind and where would you buy it at? I have asked at a few places and they look at me like I'm crazy!
  • Sow and Dipity Sow and Dipity on Apr 26, 2014
    I teach terrarium classes at my garden center and I always use a base layer of charcoal. It's available at most garden centers in small bags and at pet stores in the aquatic section.... it's used in aquariums to filter water and to deter the build up of micro organisms. Terrariums are essentially mini eco systems... the charcoal will help oxygenate the roots in a sealed bottom glass bowl, but this doesn't mean you allow a layer of water to stand at the bottom. Just add enough water to dampen the soil and not too often. You did a lovely job... enjoy your mini world ;) I posted a bunch of terrariums here in this post if you would like to check them out:
  • Kristy Kristy on Apr 26, 2014
    should I use the charcoal first and then the stones and then the dirt ect.....?
  • Sue Harrington Sue Harrington on Apr 26, 2014
    the charcoal should go between the drainage layer (sand, rocks...) and the soil. You did a beautiful job by the way.
  • Kristy Kristy on Apr 27, 2014
    Thank you! I just made a smaller one. This one I have the carbon added to it. I did take the top off to let it air dry the water on the class. It has a small Fittonia in it.