Indoor Gardens: Dish Gardens and Terrariums
by Don Janssen, Extension Educator
If looking through seed catalogs has given you the gardening bug, turn your back on the outdoors and plant an indoor garden. Dish gardens and terrariums are like miniature gardens. The main difference between them is that the dish garden is open -- the terrarium is enclosed.
The key in putting together plants for either type of grouping in a single container is choosing plants that require basically the same environment and care. A dish garden of moisture-loving tropical plants will work; a dish garden of desert plants will work. Mixing them in a single garden, however, means that you can't possibly provide care that will meet the needs of both sorts of plants.
Desert plants are more suited to a dish garden than to a terrarium because the whole point of a terrarium is to create a humid environment for plants that aren't well adapted to dry indoor air. Desert plants such as cacti and succulents not only don't need that sort of environment but also won't tolerate it.
Begin constructing a dish garden by selecting a shallow container. Pick a growing medium according to the plants you intend to plant. For desert plants, use a prepared peat-vermiculite mix with some coarse sand or perlite added, a mixture of equal parts sand and houseplant potting soil, or a mixture of 2 parts sand, 1 part soil and 1 part peat. If you want to make it even easier, simply buy a bag of prepared cacti and succulent potting mix.
For tropical plants, commercial potting soil, a prepared peat-lite mix, or a combination of equal parts sand, sterile soil and peat will do nicely.
For each garden, select several small plants that vary in size, color, form and texture. A grouping typically includes an upright plant, a trailing plant and a colorful focal point.
Fill the container with the appropriate growing medium and experiment with various arrangements of plants. In a container to be viewed from all sides, the tallest plants are usually placed near the center; in one to be viewed from one side, tall plants typically form the backdrop for the shorter ones.
Transplant plants carefully and water them in. Then set the container where it will be exposed to light levels, temperatures and relative humidity appropriate for the plants.
Succulents and cacti generally grow fairly slowly and a grouping of such plants will be slower to outgrow its container than a grouping of tropical plants. Some plants can be pruned; others will need to be removed and replaced by smaller plants to keep the dish garden from looking overgrown.
Terrariums are similar in that they consist of several plants in a single container, but they are usually planted in aquariums or large bottles or other containers that can be closed to hold humid air around moisture-loving plants. Clear bottles are better than tinted ones.
Once plants are in place and watered in, an enclosed terrarium may not need watering again for weeks. In fact, it may need to be opened if moisture builds up to the point where it is streaming down the sides.
Direct sun and a terrarium are a bad combination. Choose plants that do well in low light or supplement natural light with light from fluorescent tubes.
To keep plant groupings from outgrowing their containers as long as possible, avoid fertilizing.
Neither a dish garden nor a terrarium will last forever. When you can no longer keep it looking attractive by pruning, removing and replacing plants, it's probably time to start over with new soil and new plants.
University of Nebraska-Lincoln Extension in Lancaster County is your on-line yard and garden educational resource. The information on this Web site is valid for residents of southeastern Nebraska. It may or may not apply in your area. If you live outside southeastern Nebraska, visit your local Extension office