Moss: the Garden’s Magic Carpet
Gardening Newsletter
Vol. 9, Issue 11 - November 2014
Moss, botanically known as a bryophyte, is one of the oldest land-based plants. It is distinctive
in that it lacks flowers and true roots (instead it has slender hair-like filaments called rhizoids),
has spores rather than seeds, and relies on the air for nutrients and water. For the gardener,
there are two main forms: cushion and creeping moss.
Patches of moss drape over a stone retaining wall like pieces of green fabric.
Designing with Mosses
Moss makes a suitable lawn alternative in shady yards. Good candidates include fern leaf
(Thuidium delicatulum), feather (Hypnum spp.), piggyback (Hylocomium spp.), hair cap
(Polytrichum spp.), star (Atrichum spp.) and carpet moss (Mnium spp.). Though unsuitable for
heavy foot traffic, a moss lawn doesn’t require mowing, fertilizer, aeration or weed spraying.
Add interest with strategically placed rocks or sculptures. Logs, branches and decaying
stumps covered in moss add an undulating, quilt-like appearance to the lawn.
A moss roof is usually encountered in humid coastal and lakeside areas. Mosses are not shy
to colonize older cedar shake or asphalt roofs on houses, garages, sheds, etc. The resulting
upholstered structures are quite striking.
A skirt of moss ascending a tree trunk or blanketing shallow tree roots adds a sense of
mystery and a neutral backdrop for other plants. For this purpose, investigate tree apron
(Anomodon spp.), pincushion (Leucobryum spp.), feathered neckera (Neckera pennata) and
common Thelia and Leucodon species.
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Moss: the Garden’s Magic Carpet
Gardening Newsletter
Vol. 9, Issue 11 - November 2014
When moss covers rocks, boulders, concrete sculptures, etc., it adds a sense of maturity to
these structures. These moss-covered objects add fluidity to the garden and create a dramatic
juxtaposition of living material against non-living material. If you have trouble establishing
moss on these surfaces, submerge the objects in water over the summer; they will absorb
moisture and acquire some surface pitting. Alternatively, you may want to start with more
porous feather stone or tufa rock.
As edging beside sidewalks, stairs and patios, moss makes an excellent transitional plant
between turf and taller perennials. It’s also a useful crack filler in a stone pathway. (Make
sure the cracks are free of leaves, pine needles and stones.) Check out silver bryum (Bryum
argenteum), thread (Leptobryum spp.), common hair cap (Polytrichum commune), little
bearded (Barbula spp.), horn-toothed (Ceratodon spp.) and twisted moss (Tortula muralis).
Moss makes a great crack filler between patio paving stones.
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Moss: the Garden’s Magic Carpet
Gardening Newsletter
Vol. 9, Issue 11 - November 2014
Wildflower gardeners have long appreciated the use of fork (Dicranum spp.), nodding (Pohlia
nutans), fern (Thuidium spp.) or feather moss (Hypnum spp.) as a groundcover and rootinsulating plant for wildflowers, ferns, bulbs and sedges. Moss makes an ideal companion
for low-growing native groundcovers such as ground dogwood (Cornus canadensis),
partridgeberry (Mitchella repens), bearberry (Arctostaphylos uva-ursi) and wintergreen
(Gaultheria procumbens). Species that prefer acidic soils are often found nestled under
rhododendrons, azaleas, pieris, leucothoe, laurels (Kalmia spp.) and blueberries (Vaccinium
spp.).
Due to its propensity for dampness, moss thrives around pools, ponds, streams, waterfalls,
etc. As a bonus, it provides habitat for salamanders, newts and frogs. Investigate torn-veil
(Racomitrium spp.), bearded (Grimmia spp.) and rivulet cedar moss (Brachythecium rivulare).
Moisture from the waterfall encourages the growth of the moss.
The uniformity, low height and subdued color of moss makes it an ideal plant for bowls,
troughs, containers, terrariums and bonsai dishes. It’s also valuable for use in miniature fairy
gardens, which are quite popular these days.
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Moss: the Garden’s Magic Carpet
Gardening Newsletter
Vol. 9, Issue 11 - November 2014
Where to Obtain Moss
As it’s not commonly found at nurseries, many gardeners try to grow their own moss. This
often works, providing you meet the plant’s requirements and are patient. (It could take six
months to three years or more for the moss to become fully established, depending on the
technique used.)
To spore propagate moss, fill a screen-bottomed wooden flat with about 1” of mixed sand,
ground peat or sawdust. Cover with a piece of cheesecloth. Scatter your moss crumble (a
patch of moss broken up into small pieces) over the cheesecloth. Keep this shaded and
damp. Once the moss has germinated and filled in, move it and its cheesecloth backing to the
planting site. The cloth will decompose over time.
To propagate moss using the slurry or paste method, place pieces of moss into a blender with
a germinating medium such as buttermilk, yogurt or beer. Blend, adding enough liquid to form
a slurry. Pour this over logs, stumps, brick walls, etc. Keep the receiving surface shaded and
moist to allow the moss to germinate. (Note also that there are companies that sell packaged
moss slurry mixes that require the addition of just water.)
The moss-covered rocks on this retaining wall make a great foil for hostas.
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Moss: the Garden’s Magic Carpet
Gardening Newsletter
Vol. 9, Issue 11 - November 2014
If you have permission to collect moss, remove the transplants carefully using a putty knife or
kitchen spatula, preferably in the spring or fall on an overcast day. Be sure to take some of the
supporting soil to help in the moss’s reestablishment. Keep it wrapped in moist cheesecloth or
burlap, or store in an insulated cooler. Plant the moss immediately upon arriving home. Wet
the underside and press it firmly into place.
During the first growing season, the moss should be kept from drying out. If extra shade
is required, place a raised sheet of burlap overtop. This will also help protect against rain
and watering dislodgement. You can also use skewers or wooden pegs to protect against
dislodgement.
If you have trouble growing moss, there are mimics available, namely green Irish moss
(Sagina subulata) and the golden Scotch moss (Sagina subulata ‘Aurea’). These hardy
perennial groundcovers have true roots, produce seeds rather than spores and display small
star-shaped white flowers. They are popular as pavement gap fillers and tolerate more sun
and foot traffic than some true mosses. One interesting application is to make a checkerboard
display by mixing the Irish and Scotch mosses.
Maintenance
Moss is quite habitat specific, particularly as it relates to soil chemistry. It thrives in shady,
moist, primarily acidic soils. Many of the common garden mosses prefer a pH of 5.5 or lower.
It’s important to keep the soil surface free of debris (small stones, twigs, leaves, etc.). Remove
it using a low-pressure water or leaf blower set at a low speed, preferably in the late fall when
the ground is frozen. The use of stiff rakes and brooms is not recommended, as they could
easily dislodge the moss. When applying lawn seed, particularly shade-tolerant species, avoid
application on windy days so that it doesn’t reach your moss beds. In sunny areas, thyme
(Thymus spp.) can be a serious competitor.
When moss dries out in hot and droughty periods, it protects its more delicate upper surface
by curling its foliage around the stem to conserve moisture. While unattractive, this response
is temporary. The plants will likely bounce back with the onset of rain, mist or dew.
Moss does not take well to certain chemical fertilizers. If required, look for slow-release types
higher in phosphorous and potash, or make your own manure tea. Semi-annual applications
of buttermilk and water are also said to help.
Watering with collected rain water is recommended over tap water that contains chlorine.
Because they obtain their nutrients and water directly from the air, various mosses show
sensitivity to air pollution. Avoid planting them beside driveways and street frontages where
salt splash may be a problem.
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Moss: the Garden’s Magic Carpet
Gardening Newsletter
Vol. 9, Issue 11 - November 2014
Stones covered with moss line a path, giving the garden a Japanese feel.
A moss landscape can act as nature’s incubator for numerous tree, shrub and perennial
seedlings. Remove these intruders immediately, preferably when the soil is wet to avoid
disturbing the moss. Birds, raccoons, chipmunks and skunks delight in digging up moss to get
at grubs and other foodstuff. Netting and wire-mesh material secured to the ground can be
used to deter them.
To become better acquainted with these fascinating plants, purchase a field guide and
magnifying lens. You’ll be amazed by what you discover.
Text by Frank Kershaw
Photos by Marnie Wright
Frank Kershaw is an award-winning horticulturist with more than 35 years of experience. He
teaches garden design and horticultural courses at George Brown College in Toronto, Ontario,
and at the Toronto Botanical Garden. Frank is also a seminar presenter at Lee Valley’s
Toronto stores.
Marnie Wright ([email protected]) is a lifelong gardener, writer and passionate
garden photographer. Her Rocksborough Garden, developed over 30 years, is located in
Bracebridge, Ontario.
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