- Wild species 2010: chapter 7
- Algae living inside fungi: How land plants first evolved
- Algae, Lichens, and Mosses on Plants
- About Lichens
- What are lichens?
- What Lichens Are Not
- Why are Lichens Important?
- Moss Propagation: Learn About Transplanting And Propagating Moss
- Transplanting and Propagating Moss
- Growing Moss Plants as Outdoor Art
- Converting a mossy lawn into a ‘moss lawn’
- How To: Grow Moss
Wild species 2010: chapter 7
Mosses belong to the plant division Bryophyta (Bryophytes), which includes also liverworts and hornworts. Bryophytes are green land plants which, like all plants produce food via photosynthesis (using sunlight to convert carbon dioxide to simple sugars). While this activity is common to all plants, mosses are classified with the bryophytes (as opposed to vascular plants) because of their simple reproductive cycle and their simple anatomical structure. Features that distinguish mosses are the simple structure of the leaves and stems, lack of woody tissue, external fertilization, small size, lack of roots, and reproduction by spores.
The reproductive cycle of mosses is an important distinguishing character. The cycle comprises of two phases, a sperm and egg producing (“gametophyte”) phase, and a spore producing phase (“sporophytes”). The sporophyte phase is most familiar to people as it is the green plant and comprises most of the lifetime of the moss. Under the right conditions, the gametophyte will produce male and female reproductive structures that hold sperm and eggs. These structures can be on the same plant or on different plants. When mature, the sperm are released from the male structures (called “antheridia”) and swim to the female structures (called “archegonia”) where they fertilize an egg. The fertilization of an egg marks the beginning of the sporophyte phase. This phase is totally dependent on the gametophyte relying on it for nutrients and water. A mature sporophyte consists of a stalk with a spore capsule at the end of the stalk. The capsule contains spores that are eventually released and disperse by air currents. Upon landing in suitable habitat, the spore will germinate and develop into a new gametophyte, thus completing the cycle.
There are several hurdles that a moss must overcome to successfully produce spores and colonize new territory. The first is that water is required for the fertilization of the eggs by sperm. Thus, in arid regions or habitats where rainfall is scarce or infrequent, mosses may not have the opportunity to develop sporophytes, and thus will not produce spores. An equally important hurdle is that successful spore dispersal depends on luck and timing. The challenge is to get the spores dispersed into air currents and carried to a potential germination site. For instance, the spores of species growing in open habitats can more readily enter air currents than those of species that grow in dense woods or rock crevices. But, as already stated, spore dispersal is only a small part of successful colonization. Once a spore reaches its destination, landing in a suitable habitat or on a suitable substrate will largely determine if the spore can germinate. The majority of mosses require very specific environmental conditions (both climatic and physical) to grow and reproduce, and usually, the requirements for germination are the most stringent.
A physiological feature that distinguishes mosses from other plants is the ability of many species to withstand periods of desiccation (lack of water) and to recover from them upon rehydration. This phenomenon is known as “desiccation tolerance”, and it is exemplified also by some insects and many lichens. Desiccation tolerance is an adaptation in response to the inability of mosses to actively manage water loss from leaves and stems and other exposed structures. The issue of desiccation is compounded by the lack of roots in mosses. Without roots to absorb moisture from the soil, it is not possible to replenish water lost from the leaves by evaporation. As a result, the moisture content of mosses closely follows humidity cycles. Significantly, it is only when mosses are wet or moist that they grow since water is a necessary requirement for metabolism. When the moss’ habitat or substrate dries out, so does the moss and all growth stops. Contrast the mosses plight with that of vascular plants, most whose leaves are typically 10’s of cells thick and have thick waxy cuticles that prevent water loss, and that have extensive root systems to replenish their water needs.
While desiccation tolerance might be viewed as a disadvantage, this adaptation has in fact enabled mosses to diversify into many habitats and onto a wide variety of substrates that are impossible to be colonized by rooted plants. For instance, mosses are able to grow directly on rocks and or the barks of trees, two microhabitats that are outside the realm of vascular plants. Furthermore, the ability to grow on such substrates has allowed mosses to avoid competition with the larger and taller vascular plants, against whom they would certainly lose in any bid to acquire sunlight and water.
The small size of most mosses has played a large role in where they grow. The smallest mosses in Canada can be less that 1.5 millimetres tall (e.g., Seligeria spp.), whereas the largest may be some peat mosses (Sphagnum) that attain lengths of one meter when growing in bog pools. However, most mosses are of moderate size, varying from four millimetres to 20 centimetres. Their small size is due to the fact that mosses do not produce woody tissue that would provide the rigidity and strength to enable the plants to attain any height. Nonetheless, like desiccation tolerance, the small size of mosses can be viewed as advantageous, allowing them to grow in “microhabitats” where most vascular plants cannot. As a result, mosses can grow as epiphytes on trees and shrubs, in small rock crevices, or in animal burrows, to name a few. Where mosses dominate ecosystems, for example, in bogs, it is because they have changed the physical environment of such ecosystems to suit their needs.
The microhabitat preference of mosses has promoted much research into their use as indicators of environmental conditions in some ecosystems, such as forests. Their indicator value is useful in the management of natural resources.
Although small in size, mosses play an important role is many ecosystems. Mosses are dominant plants in many wetlands, peatlands, boreal forests, and coastal rainforest. In these systems they play an important role in controlling runoff and nutrient cycling, and influencing soil temperatures. Mosses are especially important in peatlands, which are an important ecosystem in the boreal zone of Canada. Peatlands consist of deep deposits of partly decomposed peat moss which in many places may have resulted from more than 5000 years of accumulation! Mosses are also conspicuous in the Arctic, where they predominate in many habitats, and where their diversity exceeds that of vascular plants.
Since some mosses produce an abundance of very small spores (<10 μm) that can be carried by wind, it is generally assumed that mosses are widespread and can be found everywhere. Moreover, if the species shows a gap in its range, then this gap is thought by some to likely be due to the species having been overlooked in that area. This could not be farther from the truth. Mosses show geographical patterns similar to those found in vascular plants. Fewer that 25 species in Canada are truly found worldwide where they occur on every continent.
About 40% of Canadian mosses are boreal species that can be found and recognized in many northern ecosystems of the northern hemisphere. About half of the boreal mosses are circumboreal species, meaning that they show continuous ranges throughout much of the boreal forests. Temperate mosses are of equally importance as boreal mosses in Canada’s moss flora. Like the boreal mosses, many of the mosses with distributions primarily associated with the temperate zone have wide ranges in this biome in the northern hemisphere. Montane mosses, as the name implies, occur only in mountainous regions of eastern and western Canada. Some species in this group have a truly unique ecology, being restricted to growing in snow beds that persist through most of the summer, and in some years, surviving under snow for the entire growing season. Arctic mosses range primarily at latitudes above tree line, and most occur also in arctic regions outside of Canada. A number of species have wider ranges and occur at southerly latitudes where they are found primarily in mountainous regions. Endemics are species with very restricted ranges, usually found only in one well defined region. Few mosses are endemic only to Canada and most are North American endemics whose ranges include a portion of Canada. The majority occur mainly along the coast of British Columbia or in southernmost Ontario and Québec.
Most mosses have little economic importance. The exception to this is the moss genus Sphagnum, which is commonly known as peat moss. Sphagnum is harvested in several provinces where it is processed and packaged for many uses. Certainly the most common usage is as a soil conditioner for gardens. However, the uses of peat are much more varied, and it is also used as a medium for growing mushrooms, as an industrial chemical absorbent, and as the main absorbent in some brands of feminine napkins. The importance of Sphagnum as an effective absorbent has long been known, as much research was conducted on this moss during World War I to determine which species were most effective for use in surgical dressing.
In recent years, mosses have been harvested in the rainforests of the Pacific Coast for use as packing material to help retain soil moisture in plant pots. Mosses absorb water quickly and release it slowly. In coastal rainforests where mosses are abundant, their removal by large scale harvesting by the horticultural industry can have significant effects on drainage by increasing erosion and leading to slope instability.
Algae living inside fungi: How land plants first evolved
New research from Michigan State University, and published in the journal eLife, presents evidence that algae could have piggybacked on fungi to leave the water and to colonize the land, over 500 million years ago.
“Fungi are found all over the planet. They create symbiotic relationships with most land plants. That is one reason we think they were essential for evolution of life on land. But until now, we have not seen evidence of fungi internalizing living algae,” said Zhi-Yan Du, study co-author and member of the labs of Christoph Benning, and Gregory Bonito.
Researchers selected a strain of soil fungus and marine alga from old lineages, respectively Mortierella elongata and Nannochloropsis oceanica.
When grown together, both organisms form a strong relationship.
“Microscopy images show the algal cells aggregating around and attaching to fungal cells,” Du said. “The algal wall is slightly broken down, and its fibrous extensions appear to grab the surface of the fungus.”
Surprisingly, when they are grown together for a long time — around a month — some algal cells enter the fungal cells. Both organisms remain active and healthy in this relationship.
This is the first time scientists have seen fungi internalize a eukaryotic, photosynthetic organism. They call it a photosynthetic mycelium.
“This is a win-win situation. Both organisms get additional benefits from being together,” Du said. “They exchange nutrients, with a likely net flow of carbon from alga to fungus, and a net flow of nitrogen in the other direction. Interestingly, the fungus needs physical contact with living algal cells to get nutrients. Algal cells don’t need physical contact or living fungus to benefit from the interaction. Fungal cells, dead or alive, release nutrients in their surroundings.”
“Even better, when nutrients are scarce, algal and fungal cells grown together fend off starvation by feeding each other. They do better than when they are grown separately,” explained Du.
Perhaps this increased hardiness explains how algae survived the trek onto land.
“In nature, similar symbiotic events might be going on, more than we realize,” Du said. “We now have a system to study how a photosynthetic organism can live inside a non-photosynthetic one and how this symbiosis evolves and functions.”
Both organisms are biotech related strains because they produce high amounts of oil. Du is testing them as a platform to produce high-value compounds, such as biofuels or Omega 3 fatty acids.
“Because the two organisms are more resilient together, they might better survive the stresses of bioproduction,” Du said. “We could also lower the cost of harvesting algae, which is a large reason biofuel costs are still prohibitive.”
Algae, Lichens, and Mosses on Plants
A.D. Davison and R.S. Byther, Professors emeriti of Plant Pathology, WSU
Algae, lichens, and mosses grow profusely on trunks, limbs, and twigs of many trees and shrubs. The cool, cloudy, wet weather in western Washington and Oregon is ideal for these organisms.
Algae are the simplest of green plants. They are present nearly everywhere and are numerous in almost any place that has sufficient moisture, such as on tree trunks and twigs, shrubs, soil, rocks, and walls, as well as in fresh and salt water. In large numbers, algae form the “scum” on ponds and wet areas of lawns.
Lichens have two components—a fungus and an alga living in association with one another to give the appearance of a single plant. Lichens grow on soil, on trunks and branches of trees and shrubs, and on rocks. Rarely are they found in water. Like the algae, lichens manufacture their own food. They occur in several forms, such as crusty gray, green, yellow, and white growths. Some are leaf-like, others resemble a tuft of horse hair hanging from the branches.
Mosses are green plants somewhat similar to algae except they have a complex structure that resembles stems and leaves. Because they contain chlorophyll, mosses can manufacture their own food. Mosses grow on soils, on tree trunks and branches, on rocks, and in water. Liverworts are closely related to the mosses and grow under similar conditions.
All these primitive plants contain chlorophyll and make their own food, so they do not directly injure the plants on which they grow. Heavy growth, however, may have disadvantages for the commercial operator or homeowner. Some people like the hitchhiking plants as they add a bit of color to shrubbery and trees in winter. At times, however, the growth becomes objectionable or unsightly, and it is desirable to control it.
Reduce conditions favorable for growth of these hitchhiking plants by opening up the plant canopy to allow better air circulation and light penetration. Pruning both shrubs and overstory trees may be necessary. Reduce plant numbers to open up the landscape. Algae, lichens, and moss often become established on slow-growing plants. Therefore, improve plant vigor by proper fertilization, watering, and cultural management. In moist, humid climates, these practices probably will not eliminate these epiphytic plants, but they will reduce their number and vigor.
A number of fungicides not only will control fungus diseases but also will kill algae, moss, and lichens. The copper-based fungicides, mancozeb and lime sulfur, are examples. In order to use the fungicides, you must find the plant that you want to spray listed on one of these labels. Since the dormant season is a good time to apply sprays for algae, moss, and lichen control, follow the label directions for disease control during the dormant season. You will note that during the dormant season, these fungicides are used in higher concentrations, making them more effective. They should not be used at these concentrations during the growing season because they can injure the leaves. When using these sprays during the dormant season, be careful not to get them on evergreen plants nearby because leaves may be injured. Also, lime sulfur should be used carefully around painted structures because it can stain.
One dormant spray should give adequate control. However, although the sprays may have effectively killed these growths, they will remain attached and visible for some time. Weathering and plant growth eventually will slough them off. The density of the original problem, the local environment, and the vigor of the plant will determine whether treatments are required each year.
Those using organic growing practices will find some of the copper-based fungicides and lime sulfur sprays acceptable. Cultural controls should be used in conjunction with any spray program.
There are approximately 3,600 species of lichens in North America and those are just the ones we know about! New discoveries are being made every year. Lichens are found all across North America and all over the world. They are found in a vast diversity of habitats and climates, from the Sonoran desert on the Coronado National Forest, to the alpine tundra of Alaskan mountains on the Chugach National Forest, and in the tropical rainforests of the El Yunque National Forest in Puerto Rico.
What are lichens?
Have you ever seen a lichen and knew that it was a lichen? Not many people know what lichens are, and who would? They seem as though they are from another planet! Lichens are bizarre organisms and no two are alike.
Lichens are a complex life form that is a symbiotic partnership of two separate organisms, a fungus and an alga. The dominant partner is the fungus, which gives the lichen the majority of its characteristics, from its thallus shape to its fruiting bodies. The alga can be either a green alga or a blue-green alga, otherwise known as cyanobacteria. Many lichens will have both types of algae.
What are fungi?
Fungi are a diverse group of organisms that are in their own kingdom (Fungi), separate from plants. Fungi do not contain chlorophyll or any other means of producing their own food so they rely on other organisms for nutrition. Fungi are widely known for their role in the decomposition of organic matter. They are also necessary for the survival of the ecosystem around them, such as partnering with plants and trees for nutrients and survival.
Lichens are another such partnership for fungi to gain nutrients from another organism. The algal partner photosynthesizes and provides food for the fungus, so it can grow and spread.
What are algae?
Algae are in another kingdom (Protista) separate from plants and fungi. There are several types of algae: green, brown, red, gold. They can survive in salt water and in freshwater on their own, and in any environment when part of a lichen relationship.
Although cyanobacteria are called blue-green algae, they are actually bacteria, and are part of the bacteria kingdom, Monera. The “blue” in the common name refers to the fact that they need to live in water, and “green algae” refers to their photosynthetic abilities, like green algae.
Peltigera britannica, dog-pelt lichen. Notice the bright green surface that is green algae showing through. Look closely and you will see dark spots. Those spots are pockets of cyanobacteria. Photo by Karen Dillman, U.S. Forest Service.
What Lichens Are Not
Isn’t lichen that mossy stuff on rocks and trees? When people think of lichens, many of them think of them as a kind of moss. That could not be farther from the truth.
Although moss and lichens are both called non-vascular plants, only mosses are plants. Mosses are included in a group of non-vascular plants called bryophytes. Mosses are believed to be the ancestors of the plants we see today, like trees, flowers, and ferns. Lichens, on the other hand, are not similar in anyway to mosses or other members of the plant kingdom.
Although mosses are very primitive, they still have plant-like structures that look like and function like leaves, stems and roots. They have chloroplasts throughout their entire bodies and can photosynthesize from all sides of their structures.
Lichens, on the other hand, are completely different. They do not have any roots, stems or leaves and their chloroplasts are contained only in the algae on the top surface of the lichen.
What lichens and mosses do have in common are size and habitats. In fact, mosses retain water, which is what lichens use to prolong their growth cycle. That’s why most lichen pictures will have mosses in the photos.
So, the next time you see a bunch of “mossy” stuff hanging from a tree or sitting on a rock, ask yourself, “Is that a lichen or a moss?”
Why are Lichens Important?
Lichens are important for several reasons. One of the most obvious is that they are beautiful to look at. How enchanting would the Pacific Northwest be without the long drapes of Alectoria sarmentosa (witch’s hair) hanging from the branches of the old Douglas firs and Sitka spruce? How colorful would the rocks and cliffs be in the Rocky Mountains without the reds, yellows, and greens of the crust lichens? Without these living creatures hanging off of trees or clinging to rocks, our natural areas would look pretty boring and a little more lifeless.
Another important function of lichens is that they provide a mode of survival in harsh environments where algae cannot normally survive. Since the fungus can protect its algae, these normally water-requiring organisms can live in dry, sunny climates without dying, as long as there are occasional rain showers or flooding to let them recharge and store food for the next drought period. Because lichens enable algae to live all over the world in many different climates, they also provide a means to convert carbon dioxide in the atmosphere through photosynthesis into oxygen, which we all need to survive.
One of the ways lichens directly benefit humans is through their ability to absorb everything in their atmosphere, especially pollutants. Lichens can provide us with valuable information about the environment around us. Any heavy metals or carbon or sulfur or other pollutants in the atmosphere are absorbed into the lichen thallus. Scientists can extract these toxins and determine the levels that are present in our atmosphere. The United States Forest Service National Lichens & Air Quality Database and Clearinghouse provides more information about lichen biomonitoring and how it is helping federal land managers meet federal and agency responsibilities to detect, map, evaluate trends, and assess the ecological impacts of air pollutants.
- Choose a shady spot. Low light and moss go together. While moss does not require shade, it gets less competition there from other plants–notably grass.
- Remove grass and weeds. If grass and weeds are growing within existing moss beds, the simplest removal is gentle hand-picking. Do not rake! Dr. Budke says, “If the grass is really thriving in the moss, it’s probably getting too much sun. If you want a better moss spread, increase the shade.”
- Dial down the pH: Most mosses thrive in acidic conditions below 5.5 pH, though they can also grow in alkaline and neutral soil. Low pH discourages grass and many weeds, making it easier for moss to thrive. Garden centers supply soil acidifiers.
- Spread new moss around the bare areas. There are three great techniques for doing this. Transplant moss patches are one effective way to integrate moss into the flora of your yard. “I mostly recommend transplanting patches of moss from other parts of the yard,” says Dr. Budke. “I’ve seen much practical success with that approach.” There’s also the much-discussed “moss milkshake, in which the plants are blended with water, beer, eggs, or buttermilk and then spread. According to Jessica Budke, the method is not optimal, though interesting. You could also order live moss from a supplier and follow the instructions that accompany it.
- Keep a rain barrel nearby. Moss does best with sky juice. “Tap water can be deleterious,” says Dr. Budke. “Most plants can filter unwanted minerals and substances through roots and a vascular system, but moss has neither of those. It absorbs everything directly through the cell walls.” Nonetheless, the key to happy moss is consistent moisture. If tap water is your only source, by all means, use it.
- Clear away leaves. “Matted leaves make it too dark even for moss,” says Budke. “And as leaves decay, they encourage fungi, which discourage moss.”
Moss Propagation: Learn About Transplanting And Propagating Moss
If you’re frustrated at trying to grow grass in the shady moist parts of your yard, why not stop fighting nature and turn these areas into moss gardens? Mosses thrive in areas where other plants struggle, and will cover the ground with a soft and gentle layer of color. Moss doesn’t actually have a root system or seeds like most garden plants do, so propagating moss is a matter of art more than one of science. Let’s learn more about moss propagation.
Transplanting and Propagating Moss
Learning how to propagate moss is actually quite easy. Prepare the area for a moss bed by removing everything that’s growing there now. Dig up grass, weeds and any plants that may be struggling to grow in the meager light. Rake the soil to remove any stray roots, and then water the ground until it is muddy.
You can spread moss to parts in
your yard using two different methods: transplanting moss and moss spreading. One or the other method may work best for your area, or a combination of both.
Transplanting moss – To transplant moss, pick bunches or sheets of moss growing in your yard or in a similar environment. If you don’t have any native moss, look near ditches, in parks under trees and around fallen logs or in shady areas behind schools and other buildings. Press chunks of the moss into the soil and push a stick through each piece to hold it in place. Keep the area moist and the moss will begin to establish itself and spread within a few weeks.
Spreading moss – If you have a rock garden or other place where transplanting won’t work, try spreading moss slurry on the proposed garden spot. Put a handful of moss in a blender along with a cup of buttermilk and a cup of water. Blend the ingredients into a slurry. Pour or paint this slurry over the rocks or in between chunks of transplanted moss to fill in the empty spaces. The spores in the slurry will form moss as long as you keep the area moist to allow it to grow.
Growing Moss Plants as Outdoor Art
Turn moss into a piece of outdoor art by using the moss and buttermilk slurry. Draw the outline of a shape, perhaps your initials or a favorite saying, on a wall with a piece of chalk. Brick, stone and wood walls work the best. Paint the slurry heavily within this outline. Mist the area daily with clear water from a spray bottle. Within a month, you’ll have a decorative design growing on your wall in soft green moss.
Converting a mossy lawn into a ‘moss lawn’
Moss, like other plants, can be weedy when it grows where we do not want it. It can be problematic on our roofs, driveways, and lawns. Heavy moss buildup on your roof can be bad for your home value, and moss on driveways and sidewalks presents a legitimate safety issue. But as a bryophile (“moss lover”), I would like to suggest more moss friendly options for your lawn moss.
Simply using moss killer on your lawn is only a temporary fix, and the moss is not the true problem. One or more factors is creating unfavorable conditions for grass growth, allowing the moss to succeed. Changing conditions to promote grass growth is potentially difficult, expensive, or both. Instead, consider two options for coexisting with the moss.
The first option is to just live with the moss. As long as you don’t require a pristine golf course lawn, the moss really is not that bad. It is green year-round and tolerates shade well. If your problem turf area is shaded, killing the moss will not lead to thick, full turf like that in sunnier locales. And if the area is sunny, moss will still return next year. Some lawn-inhabiting moss species are actually quite sun-tolerant.
Option two is to completely convert your moss-laden lawn to a “moss lawn” where moss cover is at or near 100 percent. Before you take on this task, first determine if it is appropriate for your situation. Perhaps the most important factor affecting a moss lawn is the intended use of the area.
One reason to have a grass lawn is its relative tolerance for wear and tear. Turfgrasses can tolerate and recover from foot traffic much better than other plants, including moss. If the area will see heavy use from playing children or neighborhood gatherings, a moss lawn may not be the way to go.
However, if foot traffic is lighter or can be mitigated by diversion or installation of a trail or stepping stones, moss can be a better, potentially lower-maintenance alternative to turf. Moss is both very eye-pleasing and requires little effort other than occasional weeding, watering and debris-clearing. Once your moss lawn is established, it will be extremely drought-tolerant, needing much less water than grass. It won’t need periodic mowing, trimming or fertilizing.
Moss maintenance is simple. Keep it weeded and remove leaves, sticks and other debris that fall onto it, and water your moss occasionally.
When first establishing your moss lawn, water it once or twice a day lightly. Moss grows when hydrated and will fill in faster with a frequent water supply. In hot weather, moss quickly dries and goes dormant but continues growing within minutes of being watered. A new moss lawn will fill in faster if it is watered more frequently. Once filled in, moss lawns only need to be watered occasionally for aesthetics or before weeding: moist moss is more wear-resistant than brittle, dry, dormant moss.
Once you have decided to convert your lawn to moss, the easiest way is to weed out the grass and alter activities to discourage grass growth. If the area you are converting already has a lot of moss, this should be easy. If not, you may need to dig out the grass and plant moss, but that is a longer process for a different article.
Without weeding out unwanted grass, there will always be a small quantity so a little kneeling and weeding will be necessary. As the grass disappears from your moss, this will get easier, consisting of occasional maintenance weeding. Ideally, weed before the grass goes to seed, spreading next years batch of weed seeds.
Besides weeding, discontinue turf promoting activities. Stop fertilizing. Turf needs regular fertilizer to grow well, moss needs no added fertilizer. Water less. Lawns need obscene amounts of water. Cut back on the total amount of water applied and water more often with less water until the moss fills in. Then water infrequently. Turfgrasses will suffer while your moss will be unphased.
One final note, do not worry too much about your soil pH. A common myth is that mosses prefer acidic soil, but the reality is that many mosses can tolerate alkaline pH levels. Adding lime to encourage turf won’t work and adding sulfur to lower pH and discourage turf may not be worth the trouble.
If any of you have converted a lawn to moss or plan to try, I would love to hear about your experiences!
Darren spends his time hand picking grass out of the moss garden at the Bloedel Reserve. When not obsessing about the moss, he can be reached at [email protected]
How To: Grow Moss
There are two main types of mosses—acrocarpous and pleurocarpous. The former grows vertically and resembles strands of hair, while the latter is characterized by a close-cropped horizontal growth habit. Gardeners have been cultivating both types for centuries, particularly in Japan, for a host of reasons: Not only does moss excel as a ground cover, but it also lends a sense of maturity to the landscape, helping a planted environment look less manicured and more natural.
How to Grow Moss on Soil
Planning to grow moss on a bed of soil? I recommend transplanting from elsewhere in your garden or a neighbor’s property. The goal is to relocate a patch of moss that’s been growing in circumstances similar to those in the spot where it will be planted. Transplanting requires no special removal techniques. Once you’ve identified the moss you want to transplant, simply use an old knife or garden spade to free up the amount of moss you’d like to—or have permission to—take.
Back on your home turf, prepare the ground with a rake. Next, dampen the soil and lay the moss on top. Once the moss is in place, press down on it firmly, pinning it down with enough rocks to ensure that the moss maintains a high level of contact with the surface of the soil. Over the next few weeks, be sure to keep the moss consistently moist. This is critical. You’ll know the moss has successfully established itself only when you can give it a light tug without shifting the material.
How to Grow Moss on Rocks, Bricks, or Pots
To grow moss on objects in your garden, such as dry stones on a retaining wall or a collection of clay pots, you need to take a different, slightly trickier approach. First, combine plain yogurt or buttermilk (two cups) and chopped moss (one and a half cups) in a bucket. Mix until the concoction becomes easily spreadable; add water if it’s too thick, additional moss if it’s too thin. Now spread the mixture wherever you would like the moss to grow. Over the next few weeks, make sure to keep the burgeoning moss moist. Within six weeks, so long as it’s been properly cared for, the moss should begin to grow rather vigorously.
How to Care for Moss
Moss likes moisture and acidic (pH 5.0 to 6.0) soil. It also likes shade. There’s no getting around it: Because moss draws nutrients via filaments, not through a root system, it dries out very quickly in the sunshine. Bear in mind that weeds can steal the moisture that moss needs, so in order to grow moss successfully, you must be a vigilant and ruthless weed killer. Finally, come fall, remember that moss cannot survive under a blanket of dead leaves. Rake—and rake often!
BELMONT, N.Y. — Moss is a much maligned yet magnificent plant. We get a lot of calls on the Master Gardener Helpline about how to get rid of moss in their lawn. I always try and convince callers of the good features of moss and wish more people could appreciate moss as it is a fascinating plant.
Moss is an ancient plant. It evolved from algae and was the first plant to be able to grow on solid ground. Moss is extremely different from other plants because it doesn’t have roots, leaves, flowers, seeds or branches. Its botanical name is Bryophyte which comes from Greek Bryophyta: bryo- meaning moss and -phyte meaning plant. The basic difference between mosses and other plants is moss lacks a vascular system. That would be like people not having a circulatory system. Moss doesn’t have the ability to transport water or nutrients throughout its foliage. So how does it stay alive?
Without roots to carry water and nutrients moss has developed the ability to absorb all the water and nutrients it needs from the air. It grows in moist shady areas where there is more moisture in the air. So how do they stay put without roots? They have specially adapted structures called rhizoids that enable them to adhere to surfaces. Moss is easily disturbed however, as anyone who has raked leaves from a mossy area has found out. The disturbed moss patches can be put back easily and stepped on with light pressure to re-establish contact with the ground.
There are more than 12,000 species of moss growing throughout the world in a wide variety of habitats including the arctic cold and hot deserts. Because they don’t depend on roots to take up water, they can live on rocks, trees, clay and even under water! Most moss grows from less than an inch high to 20 inches for the largest. They live from 1 to 10 years depending on the variety. Not producing seeds, moss spread through division and air borne spores.
One of the joys of walking in forested areas is seeing all the beautiful mosses. It seems so peaceful and relaxing. Moss is a true “evergreen”. As soon as the snow melts there it is, green and lush, and it stays that way until covered with snow again. It will go dormant if the weather becomes hot and dry but comes back after a rain.
For these reasons moss gardening is one of the newest trends in horticulture. Given the right habitat it’s easy to grow, low maintenance and beautiful. What’s not to like? Many people who have given up trying to grow grass in shady areas are turning to moss. It’s an excellent alternative. Normal foot traffic is OK but moss wouldn’t be a good choice for an area where children are playing as it tears up too easily. The easiest way to include moss in your lawn is to encourage the moss that is already there by removing other vegetation that is impeding its growth. That’s what I have been doing and it works. There are also recipes online for making a moss “slurry” with moss and buttermilk or beer to encourage moss growth. Since moss is becoming so popular there are nurseries that specialize in moss that can be mail ordered.
Over the centuries moss has been used for many things. Sphagnum moss is the main ingredient in peat moss. Because it is extremely absorbent and can absorb up to 20 times its weight and has anti-bacterial properties, moss was used as bandages throughout history including during WWI. Dried moss was used as an insulation in homes and to keep feet dry in boots as well as fuel for heat. Moss also has an important ecological role; it is a bioindicator for pollution (in polluted areas, it changes shape, density or just disappears completely), conserves water, prevents erosion, filters pollution and acid from rain and sequesters carbon.
Don’t be so quick to try and get rid of the moss in your landscape. Give moss a chance, it will add beauty to your garden.
—Lyn Chimera, Master Gardener Volunteer
Cornell Cooperative Extension
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