Sagina subulata 'Irish Moss'

There is something plain old irresistible about Irish moss. I don’t know if it’s the colour, texture or elegant simplicity that everyone loves.
Sagina subulata is one of the best low growing ground covers that is both decorative and low maintenance. Hardy to about -15°C (5°F), it spreads slowly to surround paths and stones with a dense, evergreen, emerald green carpet of tiny, soft feathery leaves that are studded with a galaxy of white flowers for a short time in mid-summer.

Irish moss is most often used as a ground cover, softening paths and stepping-stones. It gives a lush accent to rock garden and terraces. It can be used as an under-planting beneath taller plants or to cover bare soil beneath potted topiaries or other plants in containers. It is also popular for Japanese-style landscaping and can be grown under trees.

Irish Moss can be used as a lawn replacement and can also help cut down on grass space and increase your garden space. Often used strategically in smaller areas where grass is hard to grow, the plants will tolerate light to medium foot traffic. For a luxurious carpet of green, few plants can match Irish moss.

Coverage:
If you are looking to cover a large area, start by growing in pots or trays and make your own 'plug plants' by cutting the plants into squares. To give you an idea of coverage, look at the last picture attached, the sign says "One box will cover three square metres"
Irish moss will grow and spread over time. As the plants grow they create undulations and "hump up", these humps can also be cut and transplanted to other areas. These seeds, and plants are particularly small, so will need delicacy, patience and time to grow.

Sowing: Sow in late winter to spring or in late summer to autumn.
Sow February to March for planting out from June onwards. Sow mid July to the end of August for planting out the following year. Sowing to plug plant stage is around 5 to 6 weeks, to green pots is 8 to 10 weeks
Fill cells or small pots with good quality, free draining seed compost (John Innes or similar) stand the containers in water to moisten thoroughly, and then drain. Sow the seeds very thinly onto the surface of the compost. Do not cover the seed as they require light for germination. Avoid direct sunlight by shading seeds after sowing.
Use a propagator or seal in a polythene bag until after germination which usually takes 5 to 8 days at 18 to 22°C (65 to 68°F). Cold temperatures will increase the cultivation time. Keep the soil slightly moist but not wet, watering from the base of the tray, never on top of the seeds.
Remove the polythene bag once the first seedlings appear and move to a cooler area, ideally around 15 to 18°C (59 to 65°F). When they are large enough to handle transplant the plug of tiny seedlings to 7 to 10cm (3 to 4in) pots to grow on.
Seed can also be sow into flats. Once the seedlings are growing strongly, cut the flats into 5 to 10cm (2 to 4in) squares, pot on or plant outdoors as required.
Plant out into their permanent positions in late spring or early summer, after the last expected frosts. Space 15cm (6in) apart.

Cultivation:
Moss needs regular watering and occasional feeding. Feed in spring and summer with fish emulsion or a dilute solution of other fertiliser. Pull out weeds early before they take over. But don't use herbicides as they tend to damage this ground cover. Clumps may be divided in late summer or early spring.
Irish moss does well in full sun but in hotter parts of the world may suffer in the heat of summer. Add plenty of organic matter to soil and keep plants well watered.
Be sure to step them into the ground occasionally. As Irish moss matures, it tends to create an uneven, undulating surface. Many gardeners like this natural look, but if plants become too lumpy, slice out wedges to remove humps. If needed, add a fine layer of topsoil to create an even surface; remaining plants will quickly cover bare spots.

Plant Uses:
Rockeries, Ground Cover, Borders, Edging, Paths, Walls & Containers, Lawn replacement.
Low Maintenance, Evergreen.

Origin:
Sagina subulata is not a true moss; Sagina is a genus of 20 to 30 species of flowering plants in the family Caryophyllaceae (The carnation family). These are flowering plants native to temperate regions of Europe

Nomenclature:
Name by Matthias Lobelius, 1576. Sagina is from the Latin meaning ‘food for cows’ referring to its grass like appearance.
Subulata is taken from the Latin ‘subula’ meaning ‘an awl or small weapon’, (An awl is a pointed tool for making holes, usually in wood or leather.) and refers to the shape of the leaves.
The common name Pearlwort refers to the resemblance of the small spherical flowers to pearls. The common name Irish moss is also used for Chondrus crispus, a red seaweed found off the coastlines of Ireland and the common name Pearlwort is also used for Colobanthus, a flowering plant found in the Antarctic region.
The Irish name for Sagina subulata is Mongán móna.

To Clarify:
Sagina subulata (Irish Moss) is deep, green. Sagina subulata Aurea (Scotch Moss) is brighter, having a golden tint to the foliage. Scotch moss favours clay soil, Irish Moss is less particular about the soil it's grown in. Both dislike drought and the other extreme, wet feet. Both are evergreen and are covered in tiny, star-shaped white flowers in spring.