Here's a new entry from our guest blogger Helen Yoest of Gardening with Confidence. Thanks Helen!

Emerald green, rolling mounds, stillness enticing, and barefoot begging, mosses evoke a special feel, like no other plant on earth.

These primitive plants, evolved 450 million years ago -- 70 million years before ferns and tens of millions more years before the first dinosaur. As homeowners look to less maintenance and more environmentally friendly practices, mosses for a shady spot are the epitome of green.  With few demands, moss, once established, rarely needs watering, needs no fertilization, plus it will eventually knit together, suppressing weeds.

Most mosses prefer a moist, shady spot with a commonly held belief that they require an acid pH range between 5.0 to 5.5, but actually, mosses will thrive in a wide pH range, not just acidic. It is more correct to say that other plants don’t prefer pH levels of 5.0 to 5.5, so there is less competition, allowing moss colonization.

Although most mosses prefer shady woodland settings, there are others that like a range of climates from Bryum argenteum growing in the cracks of sidewalks, Tortulla muralis found in desert regions and Campylopus introflexus growing in coastal regions. Rhizoids, not roots, are what attaches moss to the ground.  Because mosses have no roots, amending the substrate isn’t necessary; moss will grow on compacted soil, even clay.

As a nonvascular plant, so primitive they get what they need from the environment -- moisture from the boundary layer of the soil, rain, dew, and even fog; nutrients and water move from cell to cell by osmosis. During times of drought, mosses go dormant. As a lawn replacement for shady locations, as the ground cover in a woodland garden, or even used in decorative dish gardens, mosses are gracing more home gardens today than ever before.

Mosses come in both clumping (Acrocarpous) and spreading (Pleurocarpous) forms.

The clumping forms, or the Acrocarps, are generally recommended for borders, as living mulch between plants or under trees -- in areas where their quilting, mounding, three dimensional effect can be appreciated.

For lawns, the spreading forms, or the Pleurocarps, are generally recommended for their ability to a form a seamless carpet.  Hypnum imponens (sheet moss), Plagiomnium cuspidatum (woodsy mnium), Thuidium delecatulum (fern moss) are good choices for shady lawn replacement.  These have low profiles, producing spreading, fast growing colonies, and a prostrate habit.  Adding more than one species is recommended to increase the chances of a moss liking it’s location, forming a dominate colony.

In spite of a preference for moist sites, we can encourage mosses to colonize in places that aren’t naturally moist, by lightly irrigating the area to allow for colonization.  Once established, mosses don’t need irrigation.  Keeping them irrigated will hasten the growth process and add intrigue, watching various mosses vie for fiefdom.

For even more interest, add woodland wildflowers to your moss, such as creeping phlox (Phlox subulata), foam flowers (Tiarella spp.), Oconee bells (Shortia galacifolia.)

Mosses’ tiny leaves are vulnerable in that they don’t have the waxy cuticles of vascular plants, absorbing rain or dew directly on the leaf surface.  Mosses convert sunlight into energy, using chlorophyll, but because moss is on such a small scale, even the tiniest leaf can inhibit their potential.  As such, keep mossy areas free of long standing debris.

Mosses reproduce through spores and leaf fragmentation.  Spore season is one of the most magical times in a moss garden.  Getting low to see a stand of moss spores is a rewarding moment, engaging even the most hardened soul.

In planning a design, know that moss gardens tolerate occasional foot traffic; moss is not as delicate as they look.   However, in areas of frequent traffic, stepping stones are recommended.

Adding moss to your garden, being green as it was in the beginning, will garner you a new perspective, making what is old, new again.

Helen Yoest is a garden writer and coach. She also serves on the board of the JC Raulston Arboretum, in Raleigh, NC.  Catch up with Helen on her blog, Gardening With Confidence. Helen also writes for the North Carolina Nursery and Landscape Association’s blog and for Moss and Stone Gardens. She is working on her first book, 50 Ways to Garden With Confidence.