For a unique holiday gift, try planting a terrarium. They are decorative, attractive and easy enough for a child to make and give. Because terrariums recycle their moisture, they can go a long time without being watered, so they need minimal care and can actually thrive on neglect.
Any clear container can be used for a terrarium and can be made from glass, plastic fish tanks, brandy snifters, pickle jars, mayonnaise jars or 2-liter bottles.
Before planting, be sure to sterilize the container of choice by washing it in hot, soapy water and rinsing thoroughly. Make sure the container has completely dried before adding the drainage material. In the base of the terrarium, put about a half-inch of small gravel. On top of that, add about a half-inch of charcoal. Then fill to proper height with a good potting soil. The soil should be slightly moist but not muddy. A thickness of about one and a half inches should be adequate. When picking plants, pick those that fit the size of the container. While they are still in the pots, decide how to arrange them before placing them inside the container. This will give you an idea of how it will look. When placing them inside the terrarium, dig the holes using an old teaspoon. Tip the plant out of its pot, being careful not to injure the roots. The potted plant should be level with the surrounding soil, and then press the soil firm around each plant.
Select two or three small plants. Be sure to pick the smallest, healthiest plants you can find. Also be sure the plants need the same amount of light. Don’t plant too many, that way the plants will have room to grow.
There are many suitable plants for terrariums, such as aluminum plant, artillery plant, baby’s tears, creeping Charlie, gold-dust plant, nerve plant, small ferns, miniature African violets, hen and chicks and miniature holly.
Water lightly so the soil is moist but not soggy. When caring for your terrarium, it’s actually good to let the soil approach dryness. Then water only enough to moisten the soil. Stop watering before you see water standing in the bottom of the container. Over-watering is the No. 1 killer of terrarium plants.
Do not fertilize. As the nutrients are used up, the plant’s growth slows down, helping keep them under control. If they are fertilized, they will quickly outgrow their container.
Keep the terrarium under an indoor grow light or by a window with bright light but not in direct sun, which will cook the plants.
Watch the terrarium for a few days. Are there drops of water on the inside of the container? Then there is too much moisture; take the cap off and let it dry out a bit. If there are no droplets of water at all, then you probably need to water it. The first few weeks are when most diseases start to appear. Any leaves that die or plants that are showing rot should be promptly removed.
This is a brief description for making a terrarium. For more information, check out the guide sheet put out by MU Extension. It is guide sheet G6520 and can be obtained by either contacting MU Extension or by going to the Web site.
Barbara Michael has been a Master Gardener since 1993, and she serves as the Master Gardener’s liaison to the Community Garden Coalition as well as serving on its board. She enjoys container gardening and houseplants. She can be reached at firstname.lastname@example.org.