So, maybe you’ve got a nice big jar that you’ve found or been gifted and you’re not really a fan of the style and upkeep needed for a tropical terrarium. The only problem is the jar doesn’t have a very big opening, or it has a cork top lid, and you’ve been reading that cactus and succulents don’t like high humidity and you shouldn’t plant them in a closed terrarium. So, should you plant them in a closed/almost closed terrarium?
The short answer is: no. I wouldn’t recommend planting drought loving plants in a closed terrarium designed to maintain high humidity. You’re asking for rot. Even if you barely watered them (lets say half a teaspoon of water every month), you’d still run the risk of the humidity being too high. As the plant breathes and fills the air with moisture, there’s nowhere for that moisture to go, hence increasing the humidity. It might be able to work in rare circumstances – but are you willing to take the risk?
You can really create some stunning pieces with cactus and succulents – if that’s what you prefer. And you’re by no means limited – some of the most beautiful jars I stock are suited to drought loving plants more. The geometric style terrariums are very rarely watertight, meaning I can’t plant humidity loving plants in them as the moisture from the substrate could leak out and damage furniture underneath.
Sometimes even something like an old candle jar, or old jam jar, can make a beautiful arrangement. Just watch your fingers when planting cactus!