Winter plant care advice is a mess of contradictions: rest your plants, don’t rest them; move them somewhere cool, keep them warm. One persistent tip is to park certain houseplants in a dark, cool spot to mimic natural dormancy and give them the downtime they allegedly crave. Because nothing says “thriving” like sticking your cactus in a closet and hoping for the best.

The theory goes that some plants need reduced light, cooler temperatures and minimal watering to complete their growth cycle. Forcing this dormancy by relocating them to a darker, cooler spot in winter supposedly yields stronger growth, better flowering and a healthier plant come spring. So basically, plant hibernation is a thing - who knew?

The prescribed method: move cacti and succulents to a cool, dark place from around October to March. Reduce watering dramatically, stop feeding entirely, and keep them between 5C and 10C if possible. That’s a pretty specific range - hopefully your unheated spare room complies.

Our intrepid tester moved some cacti to an unheated room for winter and put others in total darkness. In spring, the ones with low light were compact, firm and pushed out new growth quickly. The ones in total darkness etiolated - becoming unnaturally long, pale and weak. So total darkness is a no-go; cacti want a dim corner, not a sensory deprivation tank.

The verdict: dormancy works for the right plants. Cacti benefit from a cooler, lower-light rest in winter, though they draw the line at total darkness. Tropical plants, meanwhile, will simply get stressed - kind of like a houseplant equivalent of a bad vacation. So before you banish your greenery to the dungeon, check its passport: desert native or tropical diva?