In our series on gardening in small spaces, we first looked at gardening on decks and patios. Then we wrote about windowboxes. Now we go even further down the scale and talk about planting a terrarium.
What is it? A terrarium is a glass container, often in the shape of a globe, which can be used for growing ornamental plants that require a high level of humidity. With tropical plants, the containers can be sealed. It is left open for other plants.
What you need:
A sizable glass vessel is needed. It could be either a fishbowl, cloche or large jar. Choose a container that's wide enough to get your hand into easily — mine was a bit too narrow making it awkward for placing the plants. Low maintenance plants such as baby ferns, ivy, cacti, succulents generally are the plants that work best in a terrarium and you need to have pebbles, course sand, all-purpose potting mix and charcoal.
Putting it all together:
1) Large pebbles look attractive at the base of the vessel.
2) Then, for drainage purposes, put about 5 cms of gravel, sand, small pebbles.
3) Mix about 1/4cup of charcoal (pinch some from your BBQ. Otherwise it's stocked by some nurseries and pet shops). This keeps the soil fresh but is not absolutely essential.
4) A layer of moss will soak up excess water. It also looks interesting too. Again not essential.
5) Next comes about 9 to 12 cms of soil. All purpose potting mix can be used.
6) Make a hole for your plants and poke them in. Since I used a tall not very wide glass jar, this was tricky and I only had room for three plants — two ferns and one little plant with multi-coloured leaves.
Frances, of California Garden Centre, Miramar, demonstrates growing plants in a terrarium
Watering guide: A spray bottle is best but tiny watering can with rose attachment will do. You're aiming for dampness, not wetness. Because condensation on the inside of the glass plays a part, spraying once a week or even less should be enough for an open jar. Every 3 to 4 weeks with a closed one.
Care guide: Place near a window where it can get some sun, but not all-day sun — it is easy to roast plants living in a terrarium. Avoid putting too close to a heater for the same reason. Be punctilious about removing dead or dying leaves or the whole plant if it looks diseased — plants are at close quarters and can be easily infected.
Bay View newsletter 67, May 2016