Moss spores travel on the air and land when the breezes die down. Moss has no roots; they have different mechanisms they use for acquiring nutrients. Some mosses are able to take up nutrients from water flowing over them; they have very effective absorptive surfaces. Other mosses, such as Polytrichum, sequester nutrients directly from the soil or substrate on which they are growing and transfer the nutrients to their growing tips. Mosses also actually help filter pollutants in the air and ground water. Mosses are small, soft plants that are typically 0.4 – 4 inches tall, though some species are much larger. They commonly grow close together in clumps or mats in damp or shady locations. They do not have flowers or seeds, and their simple leaves cover the thin wiry stems. At certain times mosses produce spore capsules which may appear as beak-like capsules born aloft on thin stalks.

Mosses are usually found growing in areas of dampness and low light. They are common in both wooded areas and near streams, as well as on trees, rocks, sidewalks, gardens, and rooftops. Wherever they occur, mosses require moisture to survive because of the small size and thinness of tissues, lack of cuticle (the waxy covering to prevent water loss), and the need for liquid water to complete fertilization. Some mosses can survive desiccation, returning to life within a few hours of rehydration.

Botanically, mosses are bryophytes, or non-vascular plants. They do have a clearly differentiated stem and leaves; the lack of deeply lobed or segmented leaves and the absence of leaves arranged in three ranks all point to the plant being a moss. Mosses have a gametophyte-dominant life cycle. That is, cells are haploid for most of the life cycle, whereas in seed plants, the haploid generation is represented by the pollen and the ovule. The diploid generation is the familiar flowering plant.

The life of a moss starts from a haploid spore, which germinates to produce a protonema, which is either a mass of filaments or is thalloid (flat and thallus-like). This is a transitory stage in the life of a moss. From the tips of stems or branches develop the sex organs of the mosses. The female organs are known as archegonia and are protected by a group of modified leaves known as the perichaetium. The archegonia have necks called venters down which the male sperm swim. The male organs are known as antheridia and are enclosed by modified leaves called the perigonium.” Mosses can be either dioicous or monoicous. In dioicous mosses, both male and female sex organs are borne on different gametophyte plants. In monoicous mosses, they are borne on the same plant. In the presence of water, sperm from the antheridia swim to the archegonia and fertilization occurs, leading to the production of a diploid sporophyte. The sperm of mosses is biflagellate (they have two flagella that aid in propulsion). Without water, fertilization is not possible. Once fertilization has occurred, it takes from four to six months for the sporophyte to mature. There are also a few mosses which form green vegetative structures called gemmae on leaves or branches, which can break off and form new plants without the need to go through the cycle of fertilization. This is a means of asexual reproduction.

Surprisingly, mosses have many uses from ecological to medical, with a host of common household uses in between. One of the better known ecological uses of moss is as bio-indicators of air pollution, such as those caused by factory emissions. They are very good indicators of acid rain damage to an ecosystem as well. Mosses are also used as erosion control agents as they aid in moisture control and stabilization of soil that would either be wind blown or washed away by water. Mosses occupy an important ecological niche in arctic and subarctic ecosystems where moss symbionts provide most nitrogen fixation in these ecosystems, as compared to the leguminous associations that are responsible for this job in temperate regions.

Mosses can also be used as bio-indicators of water pollution and treatment of wastewater. Sphagnum moss, both cristatum and subnitens species, is harvested while still growing and is dried out to be used in nurseries and horticulture as a plant growing medium. During World War II sphagnum moss was utilized as dressings on soldiers’ wounds. This particular moss is highly absorbent and also has mild antibacterial properties. Legend has it that early people used this same moss for baby diapers. Peat moss can also be harvested on a sustainable basis and managed so that re-growth is possible. In Mexico, moss is used as a Christmas decoration. In Finland, peat mosses have been used to make bread during famines. In rural parts of the United Kingdom, the moss Fontinalis antipyretica was traditionally used to extinguish fires as it could be found in substantial quantities in slow-moving rivers and the moss retained large volumes of water which helped extinguish the flames.

From an aesthetic point of view, in the United States mosses are not highly acclaimed for their use in gardening. However, ornamental and garden uses of mosses are becoming more common. For centuries the Japanese have encouraged and protected moss growth in their gardens. Moss is thought to add a sense of calm, age, and stillness to a garden scene. A passing fad for moss-collecting in the late 19th century led to the establishment of mosseries in many British and American gardens. The mossery is typically constructed out of slatted wood, with a flat roof, open to the north side (maintaining shade). Samples of moss were installed in the cracks between wood slats. The whole mossery would then be regularly moistened to maintain growth.

Four mosses found in this part of the United States include:

Fern moss – a medium green moss that tolerates dappled shade and prefers sandy soil
Hair cap moss – prefers medium shade to partial sun and sandy soil
Rock cap moss – grows on rocks and boulders and is medium to dark green. It prefers shade
Cushion moss – prefers sandy soil. It prefers shade and will tolerate only partial sun. It is a lighter green color with a silvery white cast, and grows in a round, cushion shape.

Please note that successfully transplanting or moving moss is not an easy task. You must have permission from the landowner where the moss is located, take along a water bag to transport your finds, and provide your specimens with the combinations of light, humidity, and shelter from the wind. There are now retail sources for several species of moss. One of these retailers has the following paragraph on their website -

“Why consider gardening with moss? The color green has been proven to reduce stress, and there are few, if any, shades more vibrant and revitalizing than those found in cool, lush moss. For centuries the Japanese have known what we are finally realizing; that is, gardening with moss adds an amazing degree of serenity and timeless beauty to any garden. Moss is utilized in rock garden design, in conjunction with water gardens, ponds, or ferns, or simply in that shady spot where grass won’t grow. Growing moss has fast become an increasingly desirable and low maintenance alternative to grass lawns and conventional shade gardening plants.” (Moss Acres website)

If you do decide to try a moss garden there are several preparations. Please remember to do your research, prepare the location, and make the commitment to maintain what you place in your gardens. Located in the proper setting, moss is a beautiful and healthy alternative to grass and shade plants.