Irish Moss Plant: perennial, plush floor cowl

If you're looking for a ground cover that will produce tiny star-shaped flowers, you've come to the right place with the Irish moss plant. It's a great addition to a shaded rock garden, the spaces between stepping stones and next to water features. Irish moss (Sagina subulata) can even be used as a lawn substitute in some areas.

Its creeping stems tolerate light foot traffic, and as it grows it forms a dense mat that is not only pleasing to the eye but also soft to the feet. It's also relatively disease-free. Growing Irish moss and its variety, also known as golden Scottish moss (Sagina subulata "Aurea"), can add so much dimension to a garden area.

So what do you need to grow a finely textured carpet from Irish Moss or Scotch Moss? And what's the difference between the two? Where do these plants come from anyway? Read on and we'll address all of those questions here.

Good Products on Amazon for Growing Irish Moss:

Brief instructions for care

Irish moss is a beautiful, soft ground cover plant. Source: beautifulcataya

Common names Irish moss, heather pearlwort, awl leaf pearlwort, Scottish moss
Scientific name Sagina subulata
family Family of the Caryophyllaceae
Height & Spread 1 to 2 inches tall, 1 foot wide
Bright Partial shade to full sun
floor Average to fertile, well draining
water Regular light watering, once a week
Pests & Diseases Snails, moles, crown rot

All about Irish Moss

Sagina subulata aureaSagina subulata aurea is sometimes referred to as golden Scottish moss. Source: Rigid

Irish moss (Sagina subulata) is commonly referred to as heather and awl-leaf pearlwort. Scottish moss is not technically the same plant, but it is a species that is often grown similarly in gardens, although there is a specific variety of Irish moss ("Aurea") that also shares the name. Both plants are native to Western and Central Europe. These moss plants grow on banks and slopes near the fertile coast of the British Isles. But they can also be found everywhere between there and Romania in sandy, well-drained soils. Perennial Irish moss grows to only 1 to 2 inches tall and spreads about 1 foot wide. It and the scotch moss variety are often grown in rock gardens, between stepping stones, or as a lawn substitute. Both belong to the carnation family and easily seed themselves, creating a beautiful mat of soft, green, grassy moss.

The plant is known as awl-leaf pearl herb because its green leaves are shaped like an awl, a tool for poking holes in leather or fabric. However, the dense, small clusters of awl-shaped leaves are soft, and the creeping stems do not reach out to poke anyone. Small, white, star-shaped flowers with five petals bloom first in spring and then sporadically during the growing season.

After each of the white flowers bloom and die, small brown elongated capsules form and triangular seeds are produced. These fall off the low-growing plant at a moderate rate and sow themselves. In this way, the thin stems manage to spread and reproduce by themselves. One of the main differences between Irish moss (Sagina subulata) and Scottish moss (Arenaria verna) is leaf color. While Irish moss has lush green foliage, Scottish moss has golden to greenish leaves. Both have white flowers and grow similarly. So if you want to fill the space between garden paving stones, either let the color guide you.

Planting Irish moss

Plant Irish moss in the spring when the threat of frost has passed. Choose a place in partial shade to full sun with fertile, well-drained soil. This can be on your lawn, in your yard, and even on a sidewalk where pedestrian traffic is expected. Pick a room where you want to fill a gap with low-growing, green foliage and white flowers.

If you live in an area with drought or extreme heat, plant Irish moss in a container and place that container in your garden on purpose. Make sure the container has rich and well-drained soil that this moss likes. The same timing applies to containers. Wait until spring when the last frost is over. To plant this moss (Irish and Scottish varieties), rake about an inch into the surface of the soil. Then, take plugs with sufficient roots and place them on the ground or in your planter. Press the dowels lightly into the earth. You shouldn't have a problem starting these plants from seeds as well. Either start indoors in winter a few weeks before the last frost or sow directly outdoors in spring. Give them plenty of sunlight or grow light. They sprout in 2 to 3 weeks.


Irish moss without flowersA close up of Irish moss when it is not in bloom. Source: Rigid

Once established, Irish or Scottish moss will stand out and do well on its own. Let's discuss some of the conditions required to grow such a ground cover.

Sun and temperature

Irish moss prefers full sun to partial shade. In areas with high heat, partial or afternoon shade is a must. Grow Irish moss in an area that can get at least 6 hours of partial shade and no more than 1 hour of scorching sunlight per day. Ideal growing zones for Irish moss are 4 to 8. Scottish moss prefers zones 4 to 7, as zone 8 is too hot for this sensitive soil cover.

If you live outside of this range, grow Irish moss in a container and bring it in when temperatures drop below 30 degrees Fahrenheit and above 80 degrees Fahrenheit. Each extreme creates brown patches in Irish moss that bounce back in the fall and can restore it to its beautiful green color. Irish moss ideally prefers temperatures around 60 degrees. Because it is low on the ground, using frost or shade towels may not be as effective as with other plants. Therefore, ground cover must be specifically placed and placed right from the start.

Water and moisture

Always water your Irish moss in the morning before the sun has warmed the soil. Keep the soil around your plant sufficiently moist, but not soaked. Especially if it has just been transplanted, it will need a constant amount of water to take root effectively. For this sensitive ground cover, however, light watering with a soaking hose is best. Too little or too much water will cause brown stains. Plants like these prefer nutrient-rich, moist soil near the coast. This is an indication that Irish moss is not a drought tolerant plant. So keep it evenly moist! If the time of year was particularly rainy, do not water your moss plant. Again, excess water on this low-growing plant is more likely to create brown spots than the lovely green foliage you want in your lawn or garden.


Blooming Irish mossIrish moss in bloom looks like a green and white carpet. Source: mrburnes99

Grow Irish Moss (and its close relative Scotch Moss or Arenaria verna) in rich, fertile, and well-drained soil. Think of its natural habitat. Native moss plants like to grow on lush coastal slopes in sandy soil. Under the sand, the coast is filled with rich humus soil. So choose a similar area or create one in your garden, lawn or container. Prepare a mixture of compost, rich garden soil, and sand to fill the area or containers you have chosen. Many advisors suggest that the plant, at least once it has established itself, can adapt to poor soils. The ideal pH range for Irish moss is between 5.6 and 7.5.


Irish moss likes a slow release fertilizer that is applied to the ground cover once a year in the spring. However, fertilize sparingly, as high nitrogen levels can affect the spread and growth of Irish moss. Instead of growing compact and deep with too much nitrogen, it grows in a hill. Especially if you are trying to maintain a garden or lawn with little land cover, avoid too much nitrogen. Use a full spectrum 5-5-5 NPK fertilizer or opt for something that has a little less nitrogen in it. This will provide adequate nutrition for foliage and flowers without overwhelming the green growth.


There isn't much to prune with ground cover crops like Irish moss. However, if there are yellowed or brown leaves, remove them as needed.


Propagating Irish moss is easy because it is a self-sowing plant. Give him a good start in the garden and let him do his thing. Seeds tend to pop out of flower pods and help moss plants to spread like they do in the wild. However, you can collect seeds and sprout seeds indoors in the winter before the last frost. On the surface of the soil, plant the seeds in a rich starter mix that has a good amount of soilless content. You can also plant seeds directly in the garden soil or on your lawn. Place the seeds at least 8 inches apart.

Another way to propagate these plants (outside of seeds) is to separate them from a healthy section of green growth in spring or fall. Simply remove a section of the moss from your garden and pull it apart so that each resulting section has healthy roots. Then place them in the partial sun to the full sun spots of your garden. Moisturize the plants and seeds and you will have more Irish moss plants in your yard and flowers to bloom in the spring.


Sagina subulataSagina subulata tolerates partial shade. Source: Class in the Garden

When gardening Irish moss, don't worry too much if problems arise. Here are a few things to keep in mind that we covered in the previous sections.

Growing problems

As mentioned in the section on fertilizers, do not give Irish moss too much nitrogen. This makes it grow into a hill instead of a low one. High nitrogen levels could also prevent flowering, meaning there are no seeds to self-sow. Instead, use a balanced full-spectrum fertilizer sparingly.

Remember not to do it Water too muchas this can cause brown stains when gardening with Irish moss. The same applies not enough water. If brown spots appear, no problem. Remove them and let the rest of the patch continue to grow with the correct amount of water. Too much sun also causes browning in patches of Irish moss. So if you are not sure whether the spot you have chosen is too sunny or not, plant the moss in a container first, move it around as needed, and then plant it in the ground when you are sure it is placed.


The only pest the Irish moss struggles with in the garden is the infamous slug. The easiest way to deal with them in the garden is to give them a heady beer trap. You cannot resist the beer and perish when you drink it. If snails get out of hand and attack your Irish moss, try some organic snail bait. You should only need to apply this once per season.


Crown rot is the only disease that affects Irish moss. This usually occurs when there is too much water in the soil, and it's caused by the same fungal pathogens that cause root rot. Prevention is the best way to fight crown rot as it can cause death of the entire organism. If you notice yellowing leaves in areas of high humidity, remove them and let the plant dry. Then apply small amounts of water only after the earth has dried. If that doesn't improve conditions, remove the entire plant to prevent the fungus from spreading to the rest of your garden.

frequently asked Questions

Heather pearlwortSometimes referred to as heather pearl, the fine leaves are awl-shaped. Source: Futureman1

Q: Where does Irish moss grow best?

A: Irish moss prefers rock gardens, spaces between paving stones, or anywhere in your garden, ground cover is preferred. Pedestrian traffic is completely ok!

Q: Does Irish moss spread quickly?

A: Although it self-propagates from seeds, it is not a powerful spreader and is easy to remove. You don't have to worry about planting an aggressive moss.

Q: Does Irish moss come back every year?

A: In warmer areas, it can scorch a little in summer and die off in winter. But this perennial will return in temperate seasons.

Q: Can you walk on Irish moss?

Answer: Absolutely. Although the leaf shape is compared to the Pokey awl, it is soft on the feet. That is why it is often chosen as a ground cover.

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