Selaginella uncinata, the blue spikemoss, peacock moss, peacock spikemoss, or spring blue spikemoss, is a species of plant in the Selaginellaceae family. It is widely cultivated outdoors along the Gulf Coast and in greenhouses and nurseries.
As brilliantly iridescent as the colors of a peacock are the metallic bluish-green shades on peacock fern (Selaginella uncinata). Also commonly called "rainbow moss," this plant is neither a fern nor a moss, but it earns these descriptive names because of its appearance and growth habits. Other than its common names, you may also find Selaginella uncinata called "spike moss" or "club moss." Peacock fern has a mat-spreading habit with foliage that grows only a few inches high, with a typical spread up to 18 inches.
Peacock fern is not a drought-tolerant plant. The soil should stay consistently moist, which means you may need to water your plant often during the extreme heat of summer. If you notice that your peacock fern is turning yellow, check to see if the soil is too dry.
Peacock fern prospers in shady nooks and woodland gardens. It needs direct sun for no more than a couple of hours each day, and it can even flourish in full shade. A partial shade spot that works well is one that receives filtered sunlight through the overhead canopy of trees, providing much more shade than sun.
When planted on rich, humus- or compost-enriched soil, peacock fern generally receives most of the nutrients it needs. When the warm temperatures in spring prompt new growth, fertilize with a water-soluble fertilizer that’s diluted to half-strength and do a second application in midsummer.
This plant can be grown in containers. Choose a pot with enough drainage holes. You can also grow rainbow moss as a hanging plant.