A moss garden is best served by learning to work with the local shade and moisture conditions instead of trying to meet moss growing conditions․ In Tennessee‚ the hot and humid summers and clay soils are a benefit to growing moss․ Moss often grows well in areas where many other plants (including grass) would not thrive․ That damp‚ shady corner under your maples? That's prime moss real estate․
Moss: The Way to Go for Tennessee Yards
A majority of Tennessee is in the USDA zone 6b or 7b․ The humidity is comfortably high‚ and in many areas of the state there is over 50 inches of rainfall per year․ Moss will thrive just fine without help․ Unlike most decorative groundcovers‚ moss prefers our tight-packed clay soil and acidic pH‚ so there's no need to amend it․ This is one of the few plantings where """"problem soil"""" is basically a non-issue․
Picking The Right Spot
In choosing a site‚ look for an area that has dappled or full shade most of the day‚ is moist but not boggy‚ and has little foot traffic․ In some locations‚ north-facing slopes‚ the area under established trees or under a downspout or other drainage route will work․ Morning sun is generally helpful‚ but more tender moss species are scorched by the intense afternoon sun (May to August)․
The intended purpose of an area can also determine its shape and contents as a quiet meditation area‚ woodland path‚ or fairy garden that can support the placement of small figurines․ Depending on the intended purpose‚ the moss can be flat and simple or irregular with stones‚ logs‚ and hills․
Ideal Moss Types for the Southeast United States
Hypnum species (carpet moss)
provide the best option for establishing moss in Tennessee․ They spread rapidly‚ tolerate foot traffic after establishment‚ and cope well with the wide range of humidity levels characteristic of the state․ Ideal conditions lead to 100% coverage in 12-18 months․
Cushion moss (Leucobryum spp․)
will not grow in a mat but instead forms dense‚ round-bellied cushions․ It can take up to two growing seasons to cover‚ but the contrast is worth the wait if you want to layer․
Fern moss (Thuidium spp․)
is tolerant of slightly more filtered sunlight and will even thrive in areas that receive a couple of hours of sunlight in the morning․ Its leaves are feathery and resemble a miniature forest floor․
Haircap moss (Polytrichum spp․)
tends to grow taller‚ making it an ideal choice for adding some vertical texture to an otherwise flat ground cover․ Once established‚ it can withstand the dry season that descends on Tennessee during late July and August․
Mood moss (Dicranum spp․)
is the species with the """"velvety green pillow"""" look most people think of․ It does best in the constantly moist‚ deep shade situation (part of a dense canopy‚ for example) and should not be allowed to dry out even for short periods when first installed․
You don't have to pick just one․ Many of the best looking moss gardens have two or more species to create contrasting areas of flat carpet and raised textural mounds․
Installing the Moss: What The Timeline Actually Looks Like
Next‚ remove all leaves‚ debris‚ and weeds down to bare dirt so that there is direct soil-to-moss contact‚ and rake it level․ (Moss doesn't have a rooting system․ It doesn't need loose‚ crumbly soil like most plants require․ Clean surfaces that are free of leaf matter are ideal for mosses․)
Then tear the moss patches into pieces 2 to 4 inches across and press them firmly into the soil instead of burying them‚ using your hand to press them down․ Firm contact is generally more important since moss gets moisture and nutrients through its entire body‚ rather than from roots․
Water heavily at time of installation‚ and keep the entire area moist (not soggy) for 3-4 weeks․ That water then makes or breaks the installation․ If watering is skipped for even several days in the heat of summer in Tennessee‚ one will lose the planting․ In a month moss is anchored and much lower maintenance․
In a realistic sense‚ plan on 2 to 3 weeks for full visible coverage‚ 3 months for partial coverage‚ and full cover in anywhere from 6 months to 18 months․ This all depends on species and soil conditions․ If someone tells you otherwise and makes promises‚ they are deceiving you․
Ongoing Care
Mist the moss with water during dry spells․ A light mist is preferred (strong water sprays may dislodge young plants)․ A good rule of thumb that works well in Tennessee during the summer months is if it hasn't rained in 5-7 days‚ mist the moss in the early morning․
Eliminating leaves and other debris from the surface is important․ A thin layer of leaves will smother moss faster than almost anything else․ A soft brush or leaf blower on low works well‚ as raking tears up shallow moss․
Never use fertilizer․ Moss absorbs nutrients only from the air and rain‚ and fertilizer usually destroys the fragile rhizoid filaments that anchor moss to a surface․
Weeds should be pulled out (hand-weeding) as they appear․ Established moss prevents most weeds from establishing themselves‚ but new moss is sensitive to weeds during its first growing season․
Building Out The Design
Once the moss has taken‚ natural features such as river stones‚ small logs and a piece of driftwood can be added for depth and interest without detracting from the moss․ Many moss gardens also contain shade-loving perennial ferns that have similar light and water requirements to the moss and which add a vertical element and textural contrast․ Since TN Nursery already carries several ferns that will work well in these same damp shaded areas‚ creating a tiered woodland effect is easy to do from plants that are already known to thrive in these conditions rather than having to guess which ferns will or won't thrive․
A few mistakes to avoid:
Over-watering is more of a problem than under-watering‚ and moss covered in standing water tends to rot․ Avoid using mulch around moss beds‚ as bark mulch leaches acids and dries soil surfaces‚ both of which will inhibit moss establishment․ Do not walk on new plantings at all‚ including drought tolerant plants such as haircap moss‚ for the first 60-90 days․
A moss garden can be one of the easiest‚ lowest-maintenance landscape features you can plant in Tennessee․ Once established‚ there's no more mowing‚ fertilizing‚ or fighting with clay soil․ Just plan on being patient through the first season while the moss establishes itself․
