Thursday, January 3, 2013

Terrariums Basics

Michele K. Koskinen

At the recent year end party for the Master Gardeners, Kate Halus and Lorraine Busch prepared and showed the group how to make a miniture terrarium. They received their training from another Master Gardener Lori Hayes in a class presented by PHSBelow are the directions.

A workshop will be presented in late 2013 at the Second Saturday workshop. For more information:
Second Saturday workshops

A terrarium is a collection of compatible plants grown in an enclosed or partially enclosed clear container. They are most useful for small plants requiring high humidity that do not adapt well to normal home atmospheres. Once the plant is established, the terrarium begins to create a climate of its own. The plant transpire moisture through the leaves, which condenses on the glass, and flows back into the soil.
The "rain effect" allows the terrarium to go for weeks without watering.

Terrariums should never be grown in full sun.

Terrarium history:
The use of transparent containers for growing plants dates back at least 2,500 years in Greece. In the United States, terrarium culture is believed to have originated in New England, where housewives placed squawberry (partridge berry) plants in hand blown glass bowls.
The invention of the terrarium as we know it is credited to Dr. N.B. Ward, a 19th-century London physician, who was interested in growing many types of ferns in his backyard but had not been successful. While studying a sphinx moth emerging from a chrysalis he had buried in moist earth in a closed bottle, he was amazed to see a seedling fern and some grass growing inside. He watched them grow for four years, during which time not one drop of water was added nor was the cover removed.
He also developed the  “Wardian cases,” which were large, enclosed containers for growing delicate plants in the home or transporting precious plants over long distances. The terrariums most often used today are small ornamental versions of the Wardian case.

 Terrarium Containers:
Containers can be purchased or found. The can be bottles, jars, aquariums, bandy snifters, fish bowls, or other clear containers with or without lids.  A wide mouth container is best for beginners.
How to plant a terrarium:
The base layer is for drainage. Place a 1" or more layer of gravel, pebbles, or very coarse sand at bottom of container.
On top of the drainage layer put a thin layer of horticultural charcoal (not grilling briquettes). This layer cleans the air and keeps the terrarium "sweet".
The third layer consists of sphagnum peat moss or a layer of sheet peat moss. This helps absorb extra water and keeps the growing medium from mixing with the drainage layer.
The last level is the soil layer. Use a sterile potting mix and some coarse builder sand or a purchased terrarium or cactus premix. Never use beach sand.
Planting - Remove plant from pot and place in a pre-dug hole and gently pat soil around the plant. Use a spray bottle to water plant.   Soil should not be soggy. Wipe off any soil on glass. Do not use glass cleaner on inside of the terrarium.
Landscaping - Use special stones, figurines, colored sand, or other decorative items. Insure all are clean.
Plant Selection:
Use plants that are slow growing and require low to medium light.  Classic closed terrarium can include small ferns, bromeliads, pothos, dracaena, mosses, and baby’s tears.  To add color, you can layer in miniature African violets, croton, prayer plants, or lipstick plants.  For a full lush appearance, include ivy, creeping Charlie, and creeping fig. 
Open terrariums require more frequent watering since the moisture escapes into the air. Plants like philodendron, piggy-back plant, and begonias.  For filler plants, consider peperomia and ivy.  Any cactus or succulents should be grown in open terrariums to meet their lower humidity requirements.
Terrarium Maintenance:
Check the terrarium often for the appearance of condensation on the glass. If large water drops appear on the glass, leave the container open until any excess moisture evaporates.
A completely closed terrarium rarely needs water but if water is needed use very small amounts. A spray bottle is a good tool for watering.
Don't let soil get soggy. Soggy soil breeds disease.


1 comment:

  1. It is great to see you helping with the resurgence in interest in Wardian case terrariums.

    We are trying to do our part with a new website dedicated to Wardian case terrariums.