So, you've got a fairy garden or miniature landscape going, what plants will work for this?
With any luck, you will already have some of these in your garden; moss is one of the most beautiful tiny scale ground covers, and if your miniature garden will be displayed in a really shady spot, this would work very well.
Happily, moss occurs naturally on many rocks, on peat based soils, and anything in a damp shady spot.
It's surprisingly drought tolerant, and recovers overnight after a dry spell (or if you spray it with water a few times a week).
Other great options are the tiniest of all Sempervivum, the cobweb hens and chicks.
Choose one of my favorites; Sempervivum hookeri.
Each rosette is barely a quarter inch across, and there can be many of them packed into only an inch or so square.
Other larger ones (relatively speaking) are Sempervivum arachnoideum species.
The tiniest of all ground covers is Elfin Thyme, Thymus serpyllum 'Elfin' with it's tiny compact growth, and diminutive orchid like flowers. This makes a beautiful small scale planting, draping over rocks and carefully constructed walls.
There are some plants that are just plain interesting; for a tree that would fit perfectly in your miniature scene, Sedum populifolium is by far the easiest to grow, and over time with judicious pruning, the leaves will also be in scale.
It can be trained to look like a gnarled old elm or oak tree using some simple bonsai techniques.
Two of the most delicate looking, but tough plants are Sedum album 'Faro Form' and Sedum lydium. Both are only a few centimeters tall, and both have white flowers which are a bit out of scale, so they could be cut off.
They resemble little shrubs or groundcovers, perfect for the gnomes and fairies in your garden.
There are many other tiny scale plants, but these are proven to survive challenging conditions so they won't just keel over if you forget to water, or want to go away for a few days.
Additionally, these are all easy to propagate, and will produce many more plants for you to use in all the other miniature landscapes and fairy gardens you will be compelled to make.