Mosses are nonvascular plants. This means that they do not have vascular tissue (cut a celery stalk in half to see some vascular bundles) for conducting water and minerals from the roots up to the leaves and moving glucose from the leaves throughout the rest of the plant. Other nonvascular plants are algae, fungi, and liverworts. If you look closely at a patch of moss, you will see simple parts that look like leaves, stems, and roots but because they lack vascular tissue, they are not technically leaves, stems, and roots. Mosses will never grow tall because of the lack of support from vascular tissue.
You can find mosses in all parts of the globe and in all climates and in all altitudes. In the Pacific Northwest, we are blessed to have a huge variety of mosses that carpet our forest floors as well as cover shaded, moist rocks and trees. Mosses help to prevent soil erosion and they add nutrients to the soil by discharging acids which will break down minerals in the underlying rocks. They also harbour important microorganisms. They require moisture to reproduce which is why they are often found in moist, shaded areas. Mosses are also a sign of a clean environment because they struggle to survive in polluted areas.
So that is enough of the biology lesson. Mosses are incredibly beautiful and low-maintenance plants to include in your woodland garden. Use them as your primary ground cover if you can. Your deciduous and evergreen Pacific Northwest shade trees will provide the perfect moist and acidic environment for growth. You are going to be better off encouraging the moss families that grow naturally in your backyard. You can do this by raking off debris and keeping the mossy areas weed-free. If you want to encourage them still further, you can make a mixture of buttermilk and water (50/50) and spray it over the soil. I have also heard that beer and water work just as well at the same concentration. If you want to “import” a variety that you have seen elsewhere, then blend one part of your preferred moss with the same amount of buttermilk or yoghurt, and then spread over the desired area. Make sure you do not take moss from the wild, but from friend’s gardens or public ditches and the like.
I have found the most effective way of growing moss is to remove and transport entire clumps while keeping them moist and then placing them in the desired locations. If your conditions are suitable, then the moss will grow and thrive.
The moss that seems to grow naturally in my backyard is the common feather-moss. My favorite moss (I believe a variety of thyme-moss) is shown nestled around stones and ferns in the picture below . It seems to grow in very moist and shady locations and so I try to provide the same conditions in the boggy parts of my backyard.
If you live in a dryer climate, especially near the ocean, you might try growing lichen. I have included a lichen photo I took on the Sunshine Coast in BC while walking a wonderful trail at Smuggler’s Cove. Beautiful.