Terrarium is the bottle garden or plants fitted in closed glass container.
It was discovered accidently by Dr. Nathaniel Ward, a
physician, in 1827. Dr. Ward had a fern rockery in his backyard, but the ferns kept dying, due to the polluted air. Ward was also studying moths and caterpillars and while doing his experiments he kept a cocoon in a closed glass jar with bit of a moist soil. He observed it regularly and noticed that a Fern plant and a grass plant had grown in the bit of soil after few days. While many plants in his backyard died from the polluted air in London , these covered plants actually thrived. He then experimented successfully with covered containers for Ferns and grown them. The covered containers became popular and were called Wardian cases, the first Terrariums. London
Terrariums have their own self sufficient environment. A established terrarium only needs daily indirect sunlight from outside. It do not even need water for a long period of time. The oxygen produced by the plants during photosynthesis is absorbed when they respire and the carbon dioxide liberated during respiration is used for photosynthesis in the terrarium. Also moisture in the Terrarium evaporates from the soil and plant leaves and get condensed on the Terrarium roof and walls. Then, condensed water falls down and re-moistens the soil. This is a continual, closed loop process. As long as the top is sealed, this process will continue for months. So the terrarium is like a small model of Earth which works on principle of recycling of water, oxygen and carbon dioxide during photosynthesis and respiration.
Let us see what types of plants and containers, other materials and tools are required for making a terrarium -
Plants used for making terrarium –
The moisture loving plants or plants growing in semi-shady conditions, hanging basket plants, foliage plants, succulents, low growing plants are used for making terrarium. The plants which grow in low to moderate light conditions like Ferns, Bird’s nest Fern, Asparagus fern, Selaginella, types of moss for groundcover, Bird nest sansevieria, Pilea microphylla, Pilea muscosa, Pilea cadierei (aluminium plant), baby’s tears, Begonia, Peperomia sps. are used in terrarium. The plants which grow in bright light conditions like Fittonia (nerve plant), button fern, Adiantum (Maidenhair fern), parlor palm, dwarf palm, Dracaena, mini African Violets, Episcia plant, Bromeliads, False aralia, Golden pothos (Money plant), Swedish Ivy, Watermelon pepromia, oxalis, Chlorophytum (spider plant) grow well in terrarium.
Also calthea (peacock plant), Maranta (prayer plant), English ivy, Japanese sweet flag, Reddish and white Alternanthera (Jacobes coat plant), Crotons, lucky bamboo, Aspidistra elatior (Cast-iron Plant), Aralia, Dieffenbachia, Aglonema, Syngonium plant, Philodendrons, Pellionia, Pelargonium sp., Callisia (striped inch plant), Tradescantia etc. are used in terrariums. Cacti and succulents such as Scilla, Sedum, Haworthia, Kalanchoe , Chlorophytum (spider plant), Bird nest sansevieria are also used in terrarium.
The low growing plants such as Ferns, Pilea, Pepromia, Begonia, oxalis, Spider plant, Fittonia, Aralia, Reddish and white alternanthera, selaginella, small pothos (money plant), English ivy, Callisia (striped inch plant), Japanese sweet flag etc. are used for small sized bottles. While Crotons, Dracaena, Diffenbachia, Aglonema, Maranta (prayer plant), Philodendrons, Palms are used as centerpiece plants and they are used for big sized bottles (eg. 25 lit bottle).
Containers used for terrariums are made of transparent glass. The glass containers vary in size and shape, it can be any transparent glass container from a small, empty electric bulb to a large 50 lit. glass bottle. The glass containers may be wide mouthed or narrow mouthed having lid on them. The beginners mostly use wide mouthed bottles, large glass containers, fish tanks or fish bowls of size 5 – 10 lit. for making terrariums. When they become expert in making terrariums, they start using the narrow mouthed bottles or glass containers for terrariums. The experts do not only make terrariums but also decorate it with sand, coloured rocks etc. to create a landscape. They also keep coloured insects, lizards etc. in the terrarium.
When the terrarium is made in narrow mouthed container, some special tools are used for planting the plants in it. The tools are funnel for pouring brick pieces, charcoal, soil etc. in container, long wires having loop at one end used for planting the plants, a long wire with rubber cork attached at one end for spreading and shaping soil layer, a long stick for positioning the plants, long plastic spoon, scissors, sprayer or oil bottle with tube for spraying water, long forceps, blade, cotton, thread, hammer for making small brick pieces etc.
The potting mixture needed for making terrariums is made up of -
1) gravels or pebbles or brick pieces which acts as drainage layer.
2) river sand which acts as drainage layer.
3) charcoal pieces or sphagnum moss which absorbs impurities and acts as buffer layer.
4) soil mixed with compost (1 part soil + 1 part of cowdung manure or leaf mould).
5) The Fungicide Bavistin – 5 gm Bavistin (1 teaspoon) mixed in 1 liter of water.
1) Select a transparent and wide mouthed, medium sized (5 lit.) glass container with lid for beginning.
2) Select plants which are suitable for the size of container and are having same light requirement.
3) Sketch a design of terrarium on paper to decide how to arrange the plants. The tall plants must be at the centre, so that they will not block the view of small plants.
4) Take the tools and all materials required for potting in terrarium.
5) As terrarium is having very humid condition inside the container, there is a risk of catching fungal infection. So all the material must be sterilized first. For sterilization take the glass container and wash it with soap and hot water and clean and air dry it.
6) Dip all the pebbles / gravels / brick pieces and charcoal pieces in fungicide mixture (5 gm or 1 teaspoon Bavistin mixed in 1 liter of water) for sterilization. Also add 5 to 10 ml of fungicide in sand and in mixture of soil and compost (1:1) and mix it well so that it will spread in all the sand and soil. If you don’t have fungicide, then take a pressure cooker and put all the pebbles / gravels / brick pieces and charcoal pieces along with sand and soil + compost mixture in separate vessels and cook it on steam of pressure cooker to sterilize it.
7) If you want to add pesticide, then add about 5 ml of pesticide each in sand and in soil + compost mixture and mix it well. If you want to put some insects, animals in terrarium then do not use pesticide.
8) Keep the funnel on narrow mouth of container for filling it. The wide mouthed container can be filled with hands, but using funnel keeps the sides of container clean. So use funnel to keep container clean. If you don’t have the funnel then make one using cardboard paper or thin plastic sheet and use it.
9) Add the pebbles / gravels / brick pieces in container through funnel. Then remove funnel and arrange it using rubber cork wire. This layer must be at least 1 inch in size.
10) Then fill the sand through funnel and arrange it using rubber cork wire. Brick pieces along with sand layer should be about 1 to 2 inches in size or more than that.
11) Then add Charcoal pieces or sphagnum moss through funnel and arrange it using rubber cork. This layer should be about 1 inch or more than that.
12) Then add soil + compost (1:1) mixture through funnel. Arrange this layer using rubber cork wire. This layer can be of several inches according to the size of container. Take care that this layer should be about 1/3rd part of container. This layer should not exceed ½ part of container.
13) Now take the largest plant out of it’s pot and gently brush the soil of it’s roots. Separate the stems of plant if the plant is having more than one stems eg. Parlor palm. If the foliage of the plant is too large, then prune it using scissors, so that plant will be fitted in that container. Remove dry leaves if there are any.
14) Make a hole in the soil using long stick. Take plant and make the ball of roots and place it on a loop of wire. Hold the upper side of plant in one hand and by other hand insert the wire loop in the container to place the plant. Then with the long stick or forceps insert and erect that plant in hole carefully and remove wire loop. Use rubber cork to cover the roots with soil in such a manner that plant will be planted firmly.
15) Then take other small sized plant and plant it with same manner. The smallest plant should be planted at last.
16) Keep the decorative material in the container using long forceps.
17) Tie cotton on one end of long flexible wire with thread and make it wet with water. For cleaning the dirt on walls of terrarium, insert that wet cotton ball in container and swab the terrarium walls with it.
18) Then take sprayer and gently spray the water on the wall of container, so that the soil will be moistened lightly. Do not spray on foliage.
19) Then just keep that container open in shade for one or two days. Observe the terrarium carefully in this period. If the container is soggy then let the extra moisture vapourise and let the foliage dry and let only a thin layer of vapour remains on wall of container, then cover the container tightly.
20) Do not keep the container in direct sunlight, as the plants will burn by the heat created inside by the glass container. Also too much shade will affect plant growth and colouration of foliage. Always keep the container in indirect light. Filtered sunlight from curtains will do. Bright, indirect, dappled light is good for keeping terrarium. Keep changing the direction of terrarium so that all plants in terrarium will get sufficient light.
21) Always keep outer side of terrarium clean as it is only source of light for the inside plants.
22) If there is fungal infection in terrarium, open the lid, cut the infected part with blade attached to the wire, remove it and add small amount of fungicide and cover the container. Add small amount of fungicide once in a year in the terrarium.
23) If the plants are infested with pests, then open the cover, cut infested part with blade attached to a wire, remove it and add the pesticide in small amount and cover it. As terrarium is closed, there is no need of adding pesticide every year after once it is used at start.
24) Once the terrarium gets well established it doesn’t need water for several months. If the container wall remains dry, instead of thin layer of vapour, then water is less. Then spray little water on wall of container as there is no drainage hole. Then cover it.
25) Add small amount of compost if necessary in a year. Do not fertilize plants in terrarium. As chemical fertilizer might become harmful for the inside plants if added in large quantity or the plants will overgrow in that container.
26) If the plants will grow more, then open the lid, prune the plants, spray water if necessary and cover it again.
After taking all this care a well established terrarium will become ready to add a beauty in surroundings.
Note – Open terrariums are also made in the same manner, but they do not have cover on it. They are having open glass containers with open air circulation in which plants are planted. So all the plants used for closed terrarium are also used in open terrarium along with different types of cactus and succulents in addition. Dish gardens is also a type of open terrarium and they are made in shallow dish container without any drainage hole. Dish gardens are mainly used for growing cactus and succulents. In dish garden only pebbles and sand are used for potting layer in which cactus and succulent plants are grown. As open terrariums and dish gardens do not have cover, it’s light requirements are different and it can be placed in sunlight. Also it can be watered frequently, according to it’s need, as it is having open air circulation. But care must be taken that water should not be lodged at the bottom of container otherwise cactus will rot in it. Dish garden and open terrariums both are based on different concepts other than that of closed terrariums. So closed and open terrariums and dish gardens must not be confused with each other and grown in different environments as per their own requirement.