Moss

Q. One person's bane another's treasure: Moss. For years I've tried getting my potted outdoor plants--terra cotta pots--to accumulate that nice green mossy patina which I've often admired on other people's pots to no avail. Someone suggested occasionally coating them with water left over from cooking potatoes--which I tried but it didn't work for me. Can you please tell me how to cultivate moss on my pots?

A. This is more difficult to answer than one would think. They love moisture and air but some will actually thrive in full hot sun. I found an article you may wish to explore. Here is a portion:

Most mosses require shady spots making them ideal constituents of shade gardens. They also like moisture. Many moss species not only tolerate but require compacting in the soil beneath them -- just the opposite of most specimens sold at nurseries. Moss plants like a soil with a pH that is acidic (5.0 - 5.5.)

First always be extremely careful when collecting moss. The best moss to collect is that which is growing in full sun but some of the choicest places for collecting quality moss are sidewalks driveways and cobblestones. These are also the areas that get hit with herbicides weed killers oil gas salt and other chemicals. A good rinsing of the moss is always a good habit before placing on the soil. They do not have roots as we think of them. They get their nutrients from the air so chances are that the moss will not be contaminated with these chemicals but the soil may be and there may be particles lodged in the moss itself. What can be done is collect moss that is attractive and put it with some buttermilk or beer into a blender. Blend it into a thick paste about the consistency of mortar and spread it on top of common red bricks. Place these bricks into 4 inch deep trays fill the tray with water so it comes 1/2 way up the brick and place the tray in a shaded pot. In about 2-3 weeks the moss is growing and as long as it is kept damp will continue to do so. Then just lift a sheet off a brick and cut to size.