Why terrarium plants like a nice cup of tea | James Wong

Suspended in their glass bowls, terrariums are a delight but they are susceptible to mould. Here’s how to tackle it It’s one of the most frequent gardening questions I’m asked: “How do you tackle mould growth in terrariums?” On Instagram I have been asked at least half a dozen times today – and it’s only lunchtime. I guess that’s what happens when you share your tiny flat with 30 or so tanks and terrariums, in all shapes and sizes. So, as you asked, here are my tips for keeping your ecosystem under glass healthy and mould free. Terrariums are an ingenious piece of technology first invented in the 19th century by amateur naturalist Nathaniel Bagshaw Ward. He discovered that delicate, moisture-loving plants, like ferns and mosses, that were next to impossible to grow in the dry, drafty air of Victorian parlours suddenly thrived when the humidity and warmth were sealed around them in closed glass cases. Unfortunately, the same sky-high humidity levels that keep these plants alive can also be perfect for the