I have been asked this so frequently whilst setting up my store I thought I'd share my, somewhat limited, knowledge of these little gems.
I love them. They are fascinating, come in all sorts of shapes and sizes and just do their thing.
They are more properly called Tillandsia, and they almost literally grow on air, they do not need compost or other potting medium to grow. They are a type of Bromeliad, officially taking the title of 'epiphytes' just like orchids (I used my favourite search engine for those terms).
They don't follow the usual plant growth pattern, they don't really have roots, nor leaves in the traditional sense.
What roots they do have are aerial roots, designed to help the plants grip onto whatever surface they are affixed to, though they don't always grow these roots.
Their leaves absorb water and nutrients instead of roots.
They also produce the most amazingly brilliant 'flowers' and considering their size, they pack a punch!
To keep them happy and healthy I 'mist' them with water every few days and soak them once a week or so. BUT, here's the big thing: they hate being left wet, so I make sure I shake them off and leave them upside down to dry. They do rot quite quickly if water sits in the ball too long.
Preferably, I do the watering in the morning too, so they have all day to dry out. This means at night, when the plant uses its leaves to respire rather than drink, it doesn't suffocate. Neat tip I picked up somewhere.
Feeding can be tricky as its easy to over do it, so I tend to use fish tank water, or standard plant food in a low dose and probably only a handful of times a year. That's it.
They also really like air flow, so I give them plenty of space rather than cramping them up in a hot glass ball or leaving them to rot in an enclosed terrarium. I think they'd prefer lying around on a shelf all by themselves to a stuffy hot glass dome. You can even glue them to rocks, wood, ceramics, glass... to make interesting decorations or living wall hangings for a spot of interest.
These little guys are so easy to keep, they do not require clunky pots or need repotting ever.
They will pretty much grow anywhere, and I hate to plug my own products in these blogs but: I really like them in macrame hangers. Easy to spray, easy to remove for dunking and I can hang them anywhere.
I find them fascinating and so different to your everyday plant in a pot.
If these sound amazing little beauties, I highly recommend you treat yourself.
Enjoy.
Michelle