by Andrea Laine, EMGV
Moss is boss. Anyone who attended moss landscaper Annie Martin’s presentation at the Durham Garden Forum in January would likely agree. Her enthusiasm for growing moss is infectious.
I entered the presentation rather neutral on the Bryophyte family; I have not encouraged nor discouraged moss in my lawn and gardens. After hearing the presentation, I realized there was a lot I had not understood about moss and believe is worth sharing with other gardeners. The following information was obtained from multiple sources.
How moss grows
Moss belongs to the Bryophyte family and some are 450 million years old. They are non-vascular plants yet still produce photosynthesis, therefore requiring sunlight, water and nutrients to live. They absorb water and nutrients through their leaves.
Moss do not have roots; rhizoids anchor the plant to a porous surface. There are two types of moss each with their own set of characteristics: acrocarpous and pleurocarpous. Moss will grow anywhere that is porous enough to hold moisture:
- Soil
- Decaying trees
- Rocks
- Streams and waterfalls
- Asphalt pavement
- Concrete walls
- Doormats
- An old leather shoe.
Steep hillsides that are hard to mow are great places for moss. Mosses help remediate soggy spots and minimize water runoff.
Moss is one alternative for areas where gardeners desire a very low-growing ground cover. Moss thrives in shady areas unsuited to lawn growth, as well as in moist, acidic soils, providing a low-maintenance, attractive alternative to turf.
Reproduction
Depending upon the type of moss, it will reproduce by spores or by branching/fragmentation. Success for either way requires moisture.
Among a moss colony there will be male and female members. Raindrops hitting the male plants scatter the sperm to female plants. Fertilization results in spores which are analogous to a flowering plant’s seeds. Spores are housed in capsules at the tip of a tall, stalk-like form called the sporophyte (see photos below). As the spores ripen they are dispersed from the capsule and if they land on a moist and porous surface a new plant can grow.
Mosses will also send out new shoots in the spring (branching) and can reproduce by fragmentation whereby wind, water, or a human being separates a piece from the whole and provides it a moist and porous surface on which to grow.
Caring for moss
Moss is practically care-free. It will grow in nutrient poor soil, in all types of climates and habitats, in sun or shade depending on the species. Moss hydrates quickly with frequent yet brief watering sessions. Ms. Martin suggested 3 times per day for 3 minutes. As with turf grasses, it is important to remove debris so as not to inhibit photosynthesis. Debris is best removed by blowing or sweeping . Avoid raking as it can dislodge moss.
A moss garden can deliver many shades and textures of green, practically year-round. Moss do not go dormant during cold weather but may yellow, temporarily, during seasonal transitions. It is not susceptible to disease. And while deer may trample it, they are unlikely to eat it.
Many choices
There are more than 20,000 species of moss which will grow in sun or shade depending upon the species. 
According to Ms. Martin, species that generally grow well are:
- Ceratodon purpureus
- Climacium americanum
- Entodon seductrix
- Hedwigia ciliata
- Hypnum imponens
- Leucobrynum glaucoma
- Sphagnum palustre
- Thuidium delicatulum
In conclusion, I am likely to maintain my ‘let it be’ attitude toward the patches of moss that have colonized the shady, undisturbed areas and rocks on my wooded property with one exception. Having learned that bees view mosses as hydration stations, I will try to remember to water the moss every now and then, especially during dry periods.
Of note
- For local inspiration, visit the Kathleen Smith Moss Garden in the Asiatic Arboretum at Duke Gardens.
- On March 18 the North Carolina Botanical Garden in Orange County is offering an educational program about the basic biology of mosses.
- There is a bryophyte herbarium at Duke University.
Mosses can be planted with annuals, perennials and bulbs. (Photo by Wendy Diaz.)
Additional informational sources:
Capon, B. (2011). Botany for gardeners, third edition. Portland, OR: Timber Press.
http://bryophytes.science.oregonstate.edu/page3.htm
https://content.ces.ncsu.edu/extension-gardener-handbook/12-native-plants
http://www.mossandstonegardens.com/blog/knowing-your-acrocarp-from-you-pleurocarp-moss-rocks/
Unless otherwise noted, photos are from “Go Green With Moss” Facebook page.