The global horticultural industry is huge. At the Aalsmeer flower auction in Holland, 20m stems change hands every day. In the week before Valentine’s Day 200m red roses will pass through this behemoth (yes, we really are that predictable). Most of your flowers will travel via this place.

But their origins will be much farther flung. The main exporters are Kenya, Ethiopia and Colombia. Given that many producing countries with the right climatic conditions to grow at this scale are also water-scarce and low-wage economies, there are myriad ethical issues. So look for certification – the Fairtrade logo is on a number of flowers – or there’s Florverde, an eco-certification programme for flowers from Colombia. Check baseline standards and suppliers at ethicaltrade.org.

Scale and price mean we’ve lost grower co-operatives (especially in the Netherlands) as flower farms are acquired by global conglomerates. What a shame. The supply chain of everyday flowers is eye-popping, as blooms are trucked to Nairobi then flown with a stopover in Saudi, where the plane might be cooled with a hosepipe. Airfreighting flowers has been likened by industry insiders to “flying compost heaps”. These are perishable goods that once on a pallet in a plane begin to rot.

But it’s not a straight win for potted plants. Many are imported. China, for example, has 60,000 hectares given over to pot plants, and there are few details on the carbon cost of this. Also global retailers push the idea of weekly potted plants, and people are beginning to buy for colour rather than longevity.

Resist the impulse-buy of a supermarket African violet and invest in some quality pot plants (preferably from an independent nursery where they can actually tell you something about origins and expectations). If you can verify the supply chain, plants probably are the better option. Even Nasa rates house plants as air purifiers from research conducted in the 1980s. Also, once a plant is under your care, you can take control, adding vermicompost (from a wormery) or feeding with a seaweed-based organic fertiliser.

On that note, despite 500 years of collective experience of housing plants (since Columbus returned with a pineapple), we do struggle to keep them alive. The more green-fingered you are, the greater the plant’s longevity and the better your switch from flowers to plants.