Indoor Gardening – Terrariums! – How To

Well, winter is indeed inevitable at this point and before long we will all be building snowmen.  Those who have a passion for gardening might be looking for a little break considering the summer we have had.  But, alas, the itch for green begins to creep back in sometime between now and January.  What to do, what to do??  I have the perfect answer.  Indoor gardening.  Sounds difficult but actually there are many gardening projects you can complete while the ground is covered with snow.

I will cover more subjects in December, but for now I would like to start with the fabulous art of building a terrarium.  Using a tightly closed or open transparent container for growing and displaying plants is a fantastic way to grow many plants which would not generally appreciate our normal home atmosphere.  When set-up properly, these miniature gardens require minimal care.  If you get started now, they can make excellent Christmas gifts!

Supplies needed are:

(Suburban Lawn & Garden carries almost everything you will need):

  • Almost any type of clear container (fish bowl, glass jar, etc… thrift stores are a great resource)
  • Drop cloth (so you can be a little messy and have more fun)
  • Long-handled spoon (used to distribute soils and gravel)
  • Scissors (to prune plants prior to planting)
  • Atomizer or Bulb-type sprayer (for watering)
  • Growing medium (clean and sterile peat moss based potting soil preferably)
  • Horticultural charcoal (to keep the soil from becoming sour)
  • Sphagnum sheet moss
  • Clean gravel (fish tank gravel, expanded shale or sterilized pea gravel will work)
  • Plants (insuring light/moisture requirements are the same for each terrarium)
  • Distilled water
  • Decorations (optional)
  • Rain-X rain repellent (optional if your terrarium will be a plant only environment)
  • If you are using a container with a very narrow opening, you may need some long sticks, and one with a wire loop on the end for lowering plants/decorations into the container.

Be sure to ask for Janet or Nancy in our tropicals department for help finding your supplies and for other tips they may have to offer!  Now that you have everything you will need gathered together, it is time to get creative!

If you are opting to use the Rain-X, this will be the first thing you do.  Apply it to the inside of your container as directed by the product instructions.  This is a spray on/wipe off product so use in a very well ventilated area and be sure to wipe all excess off of the jar. Never place animals in a terrarium with Rain-X applied as it can be toxic for them to be near.  

Next you will fill the bottom of the container with a layer of gravel keeping in mind that approximately 1/4 of your container will consist of your base substrates.  A 1/2 inch thick layer of horticultural charcoal will be applied over the gravel.  The next step is optional, but will keep a cleaner looking presentation.  A layer of sphagnum sheet moss is placed over the charcoal layer which will help to keep the soil from mixing into the gravel.  You will need a minimum of 1 1/2 inches of potting soil on top of the sheet moss.

I have provided a list of appropriate plants for this project below.  Be sure to select those which will be well suited in the container you have chosen and can be satisfactory companions (same water and light requirements).  Click in the upper right corner if you would like to view a printable copy to take shopping with you.

When installing your plants, consider the visibility of your terrarium and arrange accordingly.  Before placing them, loosen the soil from their roots.  Make sure the leaves are not touching the sides of the glass, particularly if your container is closed.  The excess moisture collected at the site of contact will cause the leaves to rot.

Don’t forget to water your creation!  The initial watering will be about the same for closed versus open containers,  Quite simply, you will want to moisten the soil (do not cause it to be wet.  Many people prefer to use an atomizer (sprayer) or bulb type sprayer for this task. Keep in mind that your closed containers may be able to go for a few months without adding any water.  This is an excellent time to add decorations if you would like to.  The soil is moist and will easily accept objects.  Replace the lid on your closed terrarium after the foliage has thoroughly dried.

Your little plants in their glass house will need light, of course, but never direct sunlight.  The temperature inside the jar will heat up very quickly and all of your hard work will be destroyed.  Place in indirect light and monitor for plant happiness.  During the first few weeks you will want to check on moisture retention, plant satisfaction and overall cleanliness (smell, etc…).  If everything seems to be set up and in tune, the essential microbes will begin to grow which will complete the cycle of life within your bio-bowl.

Don’t be afraid to have some fun with this project, it should reflect a bit of your personality, particularly if you are giving them as gifts.  Unlike standard houseplants which require frequent attention, terrariums are easy keepers.  Aside from the occasional misting of water, your terrarium will then be fairly self sustaining for quite some time!!  Enjoy!!

The Garden that is Finished is Dead