Green thumb
Grow a whole new world with the kids these Easter holidays
As the weather cools, the range of plants we can grow in our garden expands. We can also attempt to create indoor gardens under glass. The art of growing plants under glass was a serendipitous discovery by Dr Nathanial Ward, an amateur London biologist. Dr Ward, in attempting to hatch a moth pupa in leaf mould, placed it in a glass jar. He soon discovered ferns germinating and flourishing in the constant temperature, which resulted in moisture under the glass. Dr Ward’s glass case revolutionised the growing of tropical plants in Europe’s temperate climate.
When we attempt to grow plants in terrariums we must be mindful of the ambient temperature, and although bright light is needed for the plants under glass to grow, any sunshine on the glass will quickly cook the plants, therefore the right position is crucial for the success of a terrarium.
The quest to find the ideal glass container may take you to the back shelf of the pantry, council’s recycling shop, or Grandad’s shed. Any glass container can be turned into a terrarium; wine flagons, perfume decanters, large brandy balloons, glass storage containers and glass preserving jars. A search through second-hand shops might uncover an old goldfish bowl, a large mason or growler jaw or an old glass lolly jar (are you old enough to remember them?).
Before you start to plant the terrarium, clean the glass container with a solution of one cup of vinegar, one cup of boiled water and one tablespoon of tea tree oil. Wash the container and the lid, inside and out. Polish and dry the glass to remove any stains.
Prepare the layers of planting medium and add them to the terrarium through a funnel fitted with a cardboard tube; this will prevent the soil from splashing onto the inside of the glass where it will be difficult to remove. The funnel will direct the substrate around the base of the terrarium where it can be shifted further using a long barbecue fork.
Build up the layers of panting medium in the jar starting with small charcoal pieces; cover the charcoal with a thin layer of course sand; finally, cover the sand with moist coir peat. Rake each layer carefully to the sides of the jar as necessary or landscape a mound to one side.
Select plants to suit the container and draw a plan to place the plants in the jar. Some plants suitable for terrariums are: small-leafed fittionia, dwarf African violets, selaginella, pileas, and club moss.
Dig a hollow for the first plant with the longhandled fork. Select the plant and gently wash the soil from the roots. Using a long pair of tweezers, lower the plant into the hole then rake the soil around the roots of the plant and firm in. Continue with each plant until you are satisfied.
Select some moss, rocks, driftwood and pebbles for decoration. Place each item into the terrarium carefully. Gently water the terrarium using a small watering can, but be careful not to add too much as it’s difficult to remove, so add just enough to moisten the plants and the peat.
Place the terrarium in a cool, shaded position. Leave it open for the first day or two. Check the moisture of the planting medium and if there’s condensation on the glass. Add a little more water if you judge it necessary. Seal the terrarium and place it in the chosen display position, out of the sun but close enough to a window to provide light for the plants.
If condensation does not occur, remove the lid and spray the plants and the soil with a fine mist to adjust the moisture level in the jar.
Condensation in a closed terrarium will maintain sufficient moisture indefinitely for the plants’ needs; they will grow and thrive in their own little glass world. However, once a year the plants will need to have old growth removed and a little judicial pruning will be necessary. Apply some slow-release fertiliser pellets and add some new peat to the top layer and adjust the moisture as before.
You might like to add a new ornament or an unusual rock you’ve found. It’s these little things that add a quirky note to a well-dressed terrarium. This could be a great family project for the Easter holidays.