Why BMI Is a Crock, in Pictures. So, the Guess The Rotund's Height and Weight game gave me an idea. (Oh, and hey, if you want to see a scatter graph of the results, there's one here now.) I talk a lot about how BMI is bullshit, but we all know talk is cheap.
As suggested in the above links (Thanks! ShellaB, for posting those links -- The first one was especially useful.), you can use monofilament plastic fish line to tie the fern to the basket, if needed. I stuffed my staghorn's basket with a combination of leaf litter, spaghnum, and Spanish Moss.
Ground moss plants are low-growing. Some, massed together, give a smooth appearance, including rock cap (Dicranum), fern (Thuidium), and the aptly named cushion (Leucobryum). Others have a relatively spikier appearance, including haircap and sphagnum. Both types can be used in shade gardens, depending on the look that you are trying to achieve.