I have been getting loads of questions about the sustainability of houseplants recently. To me, it’s very encouraging that people are so interested in greening their indoors (in both senses of the word). Here is a quick run down on the environmental impact of houseplants, and how to shrink it as much as you can.

The major concern I hear is that the vast majority of houseplants sold in the UK are imported, racking up “plant miles” on their journey from the huge nurseries in the Netherlands. However, all you need do is look at a map to see that Holland is as close, if not closer, to many of us here in Britain than other parts of the UK. Secondly, these plants are transported here by road and ferry, which produces not only a fraction of the carbon emissions per mile of flying, but significantly less than smaller scale deliveries would generate from UK nurseries. If you are driving to your garden centre to buy houseplants, the emissions from your car will almost certainly be greater than the emissions generated in getting it from grower to garden centre. In fact, it is fair to say that in the production chain of houseplants, transport is one of the lowest sources of carbon emissions wherever you chose to source them from.

What is the highest? According to most studies, the heating used to keep enormous glasshouses at the correct temperature. Yet due to economies of scale, these state-of-the-art glasshouses are (perhaps counterintuitively) more fuel efficient than smaller scale ones. Some growers are even seeking to lower their footprint further by outsourcing production to warmer places, such as the Canary Islands, to propagate plants outdoors without the need for heated glass. Transported to Europe by ship, this turns out to be a much greener option. Calculating sustainability can often yield some surprising results!

While there is obviously far more work that can be done, it is important to appreciate this in the wider context. Even if you have a plant collection as massive as mine (more than 500 and counting), that is nowhere near as many plants as one might have in an outdoor garden. Nowhere near as much compost, fertiliser, water, tools or car trips either. As indoor gardening involves a tiny fraction of all these inputs, relatively it really has a small carbon footprint.

So what can we do to reduce it further? First, propagate plants yourself from seed or cuttings. It’s a great way to share the love, get plants for free, and (almost) eliminate all the associated emissions.

Secondly, talk to your houseplant supplier about going peat-free (most still aren’t). As consumers, use your buying power to help push for vital change.

Don’t buy novelty houseplants that are essentially designed to die, like poinsettias, chrysanthemums and sprayed cacti. The grower philosophy here, that a short lifespan will encourage repeat purchases, is one that results in a great deal of waste and puts off newbies who blame themselves and feel disheartened.

Finally, remember that while everything we do has an environmental impact, a houseplant hobby is unlikely to be one of the biggest drivers. But there are always simple ways to shrink it further.

Follow James on Twitter @Botanygeek