Plant Irish moss as plugs, or surface-sow the seed after frost. Press plugs at the soil line in the joints between pavers.

Press plugs at the soil line between the pavers
| Factor | Recommended | Avoid |
|---|---|---|
| When | Spring after frost, while nights are still mild | Do not plant into peak summer heat unless you can keep the joints moist |
| Stock | Nursery plugs, or small rooted pieces of a mat you already have | Do not tease the roots dry and leave them sitting out |
| Where | Joints between pavers, or a small path of soil that drains | Do not set it in a baked south wall with no afternoon shade |
| Depth | Roots in contact; the green top even with the soil | Do not bury the foliage in a wet hole |
| Spacing | One plug per joint, or about 8 to 12 inches apart in open ground | Do not set pieces so far apart that weeds take the gaps |
Irish moss goes in as a small plant for a path or a patio joint. Loosen the soil in the gap, then press a plug so the roots touch the ground. [1] Wait until frost has passed, and plant the same day you bring the plugs home. [2] In open ground, eight to twelve inches apart fills in; a paver joint takes one small piece per gap. [3] Site, sun, and later watering live on How to Grow Irish Moss.
- Choose a sunny or lightly shaded joint of soil that drains. Pull weeds and loosen the top of the gap.
- Water the plugs, then press each one so the roots meet the soil and the green top sits even with the surface.
- Firm with your fingers, or step once on a board over a larger patch, then water at once to close air pockets.
- Keep the joints barely moist until the pieces root, and stay off them until they hold.
When do I plant Irish moss?
Plant plugs in spring after frost. Midsummer only works if you can keep the joints moist. Fall is possible while the ground is still warm.
How do I plant it between pavers?
Loosen the soil in the joint, press a small rooted plug so the top sits even with the soil, and water. Keep that gap moist until the piece holds.
Surface-sow the seed after frost
Seed is the cheap way to start a larger patch. Sow it on the surface after frost, or start trays a few weeks earlier and move the seedlings out when frost has passed. Press the seed onto the soil; do not bury it under a thick cover. Keep the surface moist, not soggy. Seedlings usually show in two to three weeks. [4] Harden indoor seedlings for about a week before they go out, so a first hot day does not scorch them.
- Wait until frost has passed, or start trays a few weeks before that date.
- Surface-sow the seed on a weed-free bed or a seed mix, and press it in. Do not bury it under soil.
- Keep the surface moist until seedlings show, usually in two to three weeks.
- If you started indoors, harden the plants for about a week, then set them out as you would plugs.
Do I cover the seed?
Press it onto the surface so it makes contact, and keep that surface moist until it germinates. A thick cover of soil often stops the seed from sprouting.
If new plugs dry out, the joint baked. Press the roots to the soil, keep the gap barely moist, and keep seed on the surface, not buried.
FAQ
Can I plant a large lawn of it?
A path, a patio, or a small strip is the reliable job. In a large open lawn, weeds often win the gaps before the slow mat closes, and heat browns the middle.
Can I plant in midsummer heat?
Only if you can keep the new plugs or seed moist. Spring after frost is the easier window.
Should I bury the seed?
No. Press it onto the surface and keep that surface moist. Burying it under soil often stops it from sprouting.
Recommended plants
References
- [1] Garden Guides -
https://www.gardenguides.com/92299-plant-irish-moss-between-paving-stones.html - [2] Epic Gardening -
https://www.epicgardening.com/irish-moss-plant/ - [3] Gardening Know How -
https://www.gardeningknowhow.com/ornamental/groundcover/irish-moss/growing-irish-moss-plants.htm - [4] Wisconsin Horticulture -
https://hort.extension.wisc.edu/articles/irish-and-scotch-moss-sagina-subulata-and-arenaria-verna/
This note is part of Sagina Guides.
More planting notes by plant are gathered in Planting Guides.
Updated: Reviewed by Bosquelle Editors


