Question
I've got this vision in my head of low containers around the perimeter of my balcony, with lush green moss growing in them.  I live in New York City.  Do you think this will work?  Any specific type of moss that would work best?  What kind of maintenance will be required?  Any other tips?  Thanks!

Answer
Hi Rebecca!

Growing moss in a balcony in New York City?
Let's try to do that!

First: The place should not be too sunny.
Second: Moss does not like chlorinated water. You can save rain water or allow chlorinated water to sit for three days before watering moss with it.

Most types of moss will grow in a mixture of clay and a good organic compost. Try a fifty fifty mix.
You could grow moss from spores (they are in those tiny little shower head like little capsules seen on top of mosses. Cut them up with scissors, and place them in a white paper sheet. Allow it to dry in the shade you should see some sort of a yellow dust. Those are the spores.

Sprinkle them over the well compacted soil mix and keep it always moist.
Always use a fine mist.
You could never overwater moss.

The three most common types of moss are:
Weisia Viridula, Pogonatum Contortum and Byrum Argenteum.
They can all be cultivated.
You could also harvest moss from somebody's backyard.

Good Luck!

Carlo