Make a Terrarium

A terrarium is a miniature indoor garden inside a glass container. The plants are low maintenance and are perfect for people who don't have a green thumb or who don't have time to care for a garden. You can place a wide variety of plants inside glass containers. A terrarium adds a bit of outdoor beauty and peace to desks, night tables or any place where space is limited.

Steps

Choosing Your Terrarium

  1. Decide which plants to use. Any low maintenance plant can be used to make a terrarium. Choose plants that will grow well together. Classic plants for a terrarium include (but are not limited to) ferns, mosses, succulents, and cacti.
    • Pick a plant that will stay small. You could make a terrarium big enough to house a bushy lavender, but it's easier to stick with mini plants. Choose plants that won't outgrow the terrarium container.
    • Plants that prefer shade are best. Plants inside a terrarium have to be tolerant of low levels of light - if you keep a sun lover in the dark, the plant will be stressed and will die.
    • Plants tolerant of high humidity. Humidity levels in terrariums rise quickly, so choose plants, like those from rain forests or woodlands, that grow well in such an environment.
    • If you're a beginner, pick something cheap and easy to grow. Choose a plant that's inexpensive and easy to grow.
  2. Choose a container. You will need a glass container that is deep enough for your plants' roots. The container you use can be an old fish bowl or one specially made for growing plants.
    • Cloches - these have high levels of humidity, and the cloche will need to be raised occasionally to give plants inside a breath of fresh air.
    • Lantern cloches - though these have high levels of humidity as well, lantern cloches are easier to ventilate.
    • Bell jars or apothecary jars are a pretty option for a taller terrarium.
    • Wardian cases - available both closed and not airtight.
    • Aquariums - aquariums work well as terrariums, and can be left open or fitted with a piece of glass.
    • Vases, tureens, or compotes - terrariums can still work their magic with an open top, though you will have to water the plants inside any container that isn't airtight.
    • In this example, a glass bowl similar to a goldfish bowl was used (pictured).
  3. Decide where to keep the terrarium. Terrariums are ultra low maintenance, but in order to remain so they must be placed in an ideal location.
    • Light: All plants need light, and plants in terrariums are no exception. However, since glass magnifies, choosing direct light is foolhardy. Instead, choose a location where your plant will receive plenty of indirect light. Or you can choose fluorescent lights, but always follow safety rules when purchase gardening-specific lights.
    • Temperature: Terrariums should be kept inside, in a warm room (mudrooms, cold porches, and other such rooms aren't good options unless you're ready to risk the terrarium freezing). Keeping a terrarium next to a heater or AC unit is also unwise; Avoid extreme temperatures or sudden changes in temperature.
    • The right surface: Avoid placing a terrarium on easily damaged furniture. Also, avoid places where young or energetic children, or pets, can access it.
  4. Purchasing supplies. To make a terrarium, you will need:
    • Potting soil. Choose light soil with lots of drainage, and preferably sphagnum/peat moss included. To check drainage, lightly wet soil and hold it in your fist: when you open your hand, heavy soil will clump, whereas light soil will fall apart.
    • Pebbles or gravel. Both provide drainage when placed at the bottom of the terrarium, and a neat appearance when placed at the top of a terrarium. Choose stones 1/4 of an inch or smaller for drainage, but choose whatever you'd like for topdressing.
    • Activated charcoal. Unless the container the plant will be in has a drainage hole, use activated charcoal pieces, which you can purchase from aquarium supply stores or garden centers. This keeps soil fresh.
    • Sheet moss. Sheet moss is useful when lining the bottom of the terrarium. It provides a "sponge" for absorbing excess water.
    • Gloves. Whenever handling sheet moss, you should be wear gloves and a long-sleeved shirt to prevent fungal infection. Gloves are also helpful when handling charcoal.
    • Decoration Pick any decoration you'd like to add to your terrarium, as long as it won't be damaged by exposure to water. Examples include miniature garden gnomes, shells, rocks, small statues or aquarium decorations.
    • Avoid adding "critters" to your terrarium. These can damage plants and spread diseases.

Planting Your Terrarium

  1. Clean the glass container. If the container was previously used, wash it thoroughly with soapy water and rinse it well to remove all soapy residue. A dirty terrarium grows bacteria over time, so use an anti-bacterial soap if you can.
  2. Add rocks for drainage. Mix the gravel/pebbles with a generous handful of charcoal. Put a layer about an inch high of this mixture inside the terrarium container.
  3. Add a layer of moss. Moss will prevent soil from filtering down into the gravel.
  4. Put in the soil. Depending on the size of the terrarium and the length of the plants' roots, you should be adding about two or three inches of soil. Gently pack it down to remove air pockets and level the surface. Dig small holes into the soil where you will put the plants.
  5. Add the plants. Remove a plant from its container and tease the roots gently apart to remove excess soil. Nestle it carefully into a hole you made previously and add more soil around it, patting it down gently. Repeat with the rest of the plants.
  6. Add the decoration. You can also add moss or pebbles to neaten the top of the terrarium.
  7. Give your plants a bit of moisture. Lightly water your terrarium and you're done![1]

Maintenance

  1. Water your plants. If your terrarium is open, water the plants occasionally. This won't be necessary for airtight terrariums, but plants in open terrariums will need to be watered once a week. Succulents and cacti only need to be watered once a month.
  2. Keep your plants healthy. If you see weeds, mold, or sick plants, remove the affected area immediately. Also, remove wilting parts of the plant, such as old flowers.
  3. Let some fresh air in. If your terrarium is airtight, air it out. Though this usually isn't necessary, if your plants are wilting or there's condensation on the sides of the terrarium, air it out (for example, by propping the container slightly open by putting a rock underneath the edge).



Tips

  • Many plants will start from cuttings or leaves. If you know someone who grows these plants, ask to take a small start.
  • Don't put a terrarium in a dark corner; terrariums require lots of indirect light.
  • Tropical plants are best because they like humidity and look very colorful.
  • Some large plant stores have sections devoted to small, terrarium plants.

Warnings

  • This article describes a decorative terrarium for plants. If you want to build a terrarium to keep a frog, turtle, or other animal, be sure to read about the needs of that animal.
  • Do not over-water plants. Only water if the soil and the sides of the glass are dry.

Things You'll Need

  • Light potting soil with plenty of drainage.
  • Pebbles or gravel.
  • Activated charcoal pieces.
  • Sheet moss.
  • Gloves and a long-sleeved shirt.
  • Decoration. (optional)

Related Articles

Sources and Citations

  • The New Terrarium: Creating Beautiful Displays for Plants and Nature, by Tovah Martin.