Tam-Tam's Blog

Terrariums: The Basics- Part Five
Jan 16, 2008 | 11:02 AM PST
Tags: tank terrarium , bottles , jugs , planting

The Tank Terrarium,  Bottles & Jugs:

The tank of course, is an aquarium tank.  Aquarium tanks come in several sizes and you have the options of using glass or acrylic.  The information that I have is for the glass.  If using acrylic, note that it scratches easily, and is known to hold in heat better than glass.

You can buy a new tank or use the old tank that is packed away in the garage.  Just note that once you use the tank for gardening, it will not be suitable for fish keeping again.  So make sure this is what you want to do with your tank.

Before you begin to plant a tank terrarium you will need to have all your materials ready and organized.  You also need to have your plants ready and know where the terrarium will be placed when completed.  Make sure to set aside a decent block of time to complete your project.  Even if all goes well, you may find it will take longer to complete the project than you expected.  You can't do a little here, and come back later, this gardening project has to be completed from start to finish, so try to do it when you know you will have no distractions.

One more thing I would like to mention here is activated charcoal.  The kind that is used in aquariums.  A thin layer of this charcoal, over the gravel layer, can help keep the terrarium 'sweet', in other words it absorbs odors.  More is explained about charcoal below.

1.  Clean The Tank.
The tank must be thoroughly cleaned with hot soapy water, then rinsed several times to remove all traces of soap.  Next, let the tank dry completely.  This is very important because if the sides of the tank are wet or damp the soil may stick to them and it can be a job to try to clean them up after planting.

If a used tank is being reused for the terrarium, there may be stubborn stains  that will not clean up with just soap and water.  If you use a glass cleaner or household ammonia to remove these stains, make sure to rinse well and do not plant the tank for at least three days.  This will give the noxious fumes time to disperse before planting.

2.  Bottom Layer.
If you have decided not to line the bottom of the tank with dry or live moss, go on to step 3.  Otherwise, line the bottom of the tank with a layer of dampen, and rung out Sphagnum moss, or use sharp scissors to cut live moss into manageable strips and lay them down, overlapping the strips in the tank, moss (green) side down.  Depending on the size of the strip of the moss and the size of the tank, you may be able to lay down just one or two strips of the live moss to cover the bottom of the tank.

The thickness of the liner layer will depend on the depth of the soil that will cover it.  If the soil slopes up from the front to the back of the tank, the layer of moss will be less in the front and thicker in the back.  For instance, less than an inch in the front to several inches in the back.  If the garden plan contains a "hill" in the landscape, put extra moss under it.

3.  Gravel Layer.
Spread the gravel evenly over the moss or unlined bottom of the container.  The terrain in a terrarium is created by the soil, not the gravel.  Don't forget to use one-eight of an inch of gravel for every inch of soil depth.  This would also be a good time to add a thin layer of activated charcoal.  You can find it in the pet section of your favorite department store or at any pet stores.  The charcoal acts like a detoxifier, helps to keep the soil from smelling bad.  If you did not use a layer of moss for a bottom layer, you may want to use it as a thin layer between the gravel and the soil so the soil does not seep into the gravel layer.  This layer should be the dry Sphagnum moss, which has been dampened and rung out.  Personally, this is where I would put the moss layer, but that is just me.

4.  Soil Layer.
Cover the gravel (or moss layer) with the amount of soil required by the size of the tank.  One inch of soil for every four inches of container height.  If the soil is dry and dusty, you can sprinkle it lightly before moving it into the tank.  Dampened soil can be kept in a plastic bag.

Once you have added the soil to the tank you can build the terrain.  The basic design is usually high in the back and gently sloping to the front.  Once you have your terrain designed you can start landscaping and planting.

5.  Planting The Garden.
When you remove the plants from their pots, try to keep the soil ball intact.  Set the plants as deep as they stood in the their pots and tamp the soil around them.  When placing the plants, gently spread out the root system and try to dig the holes large enough to accommodate the root system.  If you are planting ferns, remember to set fern crowns just above the soil line.

6. Watering In The Plants.
After the plants are in place it is time to water.  Use a hand sprayer to water them and then cover the container.  If you are using tap water to water in your plants, let it set for several hours ahead of time to reach room temperature.  African violets and woodland plants could benefit from being watered with rainwater.

Do not drench the soil when watering.  Excess water can't evaporate in a sealed container. If there is too much water in the container the soil will become soggy and the roots will rot, but you do need to apply enough water to start the rain cycle.  If condensation doesn't form on the sides of the closed container, one of two problems may be occurring.  One, not enough water has been applied to start the rain cycle, or two, the cover is not completely sealed.  Make sure the cover fits snugly.  Gaps between the cover and the tank can be sealed off with transparent tape.

7.  General Tank Clean Up.
You will want to clean any mud or other stains off the inside walls with a lint-free cloth.  A vegetable brush may come in handy to work on areas where the plants have rested against the sides.  A clean make-up brush would be ideal for cleaning off the foliage.  Very carefully use a window cleaner to remove fingerprints and smudges on the outside of the container. 

8. Finally...
move the terrarium to a cool shady location for two or three days to help the plants adjust to their new environment then place the terrarium in its permanent location.
If heavy "rain clouds" condense on the sides, lift the cover and ventilate the plants.

Extra Stuff:
If you plan on planting a desert terrarium which contains cacti or succulents, remember that these plants will not benefit from a sealed container.  They will need the cover ventilated for air circulation.  You may want to add some more drainage material and make sure the soil mix you choose is appropriate for the plants.  When planting cacti, it might be safer to leave them in their pots.

Bottles And Jugs:

Bottles and jugs must be thoroughly cleaned and rinsed well before planting.  Like the tank terrariums, they need to be completely dry inside before adding any of the materials.  This can become a bit of a chore because it is sometimes hard to get all the moisture out of a bottle or jug.  One idea is to carefully direct a stream of air into the neck of the bottle, using an electric fan or hair dryer.

It is also more difficult to add the moss layer into the bottle or jug because a specific amount of moss must be used.  You will need to make a paper pattern that is equal to the circumference of the base of the container plus one fourth of the bottle's height.  For example, if the base of the container is eight inches around and its height is twelve inches, the pattern should have the circumference of eleven inches (base measurement plus one-fourth of the container's height).  Check the measurement of your paper pattern by inserting it into the container before cutting a one piece liner from a sheet of moss.

Before placing the one piece liner into the container, cut several one inch slits along the edges so it will not bulge up.  It will help the liner to conform to the shape of the container.  If the opening is not large enough to get the one piece liner in the container, then cut the liner into individual sections, like cutting a piece of pie and add them to the container individually.  When using live moss make sure to put the green side down against the bottle's bottom.

Multi-gallon jugs like the five gallon carboys that are used to hold spring water can make beautiful terrariums.  They also allow the glass gardener to use taller plants because of their height and their capacity makes it nice to landscape.  They are also easier to landscape if they have wider openings that you can use tools like the grabbers in. 

Use the regular procedure to plant the carboy, but if you are planting taller plants, remember to add more soil for plant support and to accommodate the taller plant's root system.  Keep this in mind for all containers where taller plants will be planted.  Before planting tall containers make sure your tools will be long enough to reach the soil level.  If they don't, you can always extend the length of your tools by attaching them to dowels with electricians tape to secure it.

Next:  Terrarium maintenance, and other handy ways to use a terrarium.