Of all the many ways there are to enjoy growing plants indoors, terrariums and dish gardens are some of the most interesting. Both of these types of indoor gardening have been around for hundreds of years and have adapted well to the plants and containers available today. They have a definite style of their own and once you understand them, maintaining them is easy.

What is a dish garden?
Traditionally, dish gardens were collections of similar plants growing in a container that had no drainage, hence the name dish gardens. Because that required special care, now dish gardens are now planted in shallow dish-shaped containers with or without drainage.

What is a terrarium?
By definition, a terrarium is an enclosure, usually made of glass, for raising plants indoors. Its most important advantage is that it creates a humid environment.

Are there different types of terrariums?
They can range from the classic glass structures with a Victorian style to aquariums to large brandy snifters. To work as a terrarium, the container simply needs to be constructed of glass (or Plexiglas) and enclose the plants on all sides. It will have one section that opens, usually on the top. The glass should be clear or very slightly tinted.

What is a bottle garden?
It is simply a terrarium planted in a bottle-shaped container, with a narrow neck and very small opening. Bottle gardens are more difficult to plant, but they provide optimum growing conditions for plants that love humidity because the bottle traps the moisture given off by the leaves of the plants.

How do I care for my dish gardens and terrariums?
Care instructions will vary with the type of plants in these containers and the conditions where you are keeping them, but there are some basics rules you can follow.

What are the basic rules for watering dish gardens?
If your dish garden is growing in a container without drainage, you will need to be very careful to avoid over watering Because the surface soil can dry quickly, it isn't a good indicator that the plants need water. If you can, dig down an inch or so and if you feel moisture, don't water yet. Another option is to press hard on the surface of the soil and if you feel moisture, leave it alone. You can also watch and let your plants show you that they need moisture. If the dish garden has drainage, it can be watered like any other indoor plant.

Can you tell me how often they will need water?
This will vary drastically. Many dish gardens are planted with cacti and succulents. They can often go a month without watering. Dish gardens can also be planted with tropicals. They might need watering much more often. How often you need to water will also be influenced by room temperatures and humidity.

Tell me about watering terrariums.
Most terrariums are enclosed environments that capture the moisture given off by the plants and use it again, so they won't need water as often. The easiest way to judge when they need more water is to watch the color of the soil down the side of the container. You will see lighter colored, drier soil on the surface and darker, moist soil at the lower levels. As the moist level shrinks, add more water. As with dish gardens, watch the plants for signs that they need water.

How should I fertilize dish gardens and terrariums?
During the spring and summer, feed once a month with a water soluble fertilizer. Avoid feeding indoor plants in fall and winter, allowing the plants to rest while the light levels are lower.

How much light do they need?
This will differ somewhat based on the types of plants being grown. Most plants would prefer 12 hours of light each day. When they don't receive enough light, the plants tend to grow thinner, taller and weaker. Dish gardens and terrariums do very well with supplemental light, especially if it is fluorescent. Incandescent light can be used on a dish garden, but it produces too much heat for a terrarium.

Should I do any trimming or pinching of the plants?
Even when great care is taken to fill the dish gardens and terrariums with the right plants, they will eventually need some trimming. If plants grow too tall or wide, thin them by snipping out the appropriate stems all the way to the base of the plant. To encourage branching, you can pinch off the last set of leaves on each branch. Unfortunately, many dish gardens and terrariums are over-planted, requiring frequent attention to keep the plants healthy and the right size.

Do plants ever outgrow a dish garden or terrarium?
Eventually, plants will outgrow these planters, especially many of the tropicals. Slower growing plants such as cacti may be able to stay in the same container for years. With careful selection, it is possible to use varieties that will stay the right size for a long time. When trimming is no longer enough to keep the plants the appropriate size for the containers, you can take out individual plants and replace them, or simply start over again. If the planter develops a salt buildup from the city water and fertilizers, it may need to have the soil exchanged after a few years.