How to Take Care of Rainbow Moss (The Final Guide!)

The rainbow moss, or peacock fern, is nearly impossible not to take home upon first sight. Its shimmery iridescent leaves are hard to find in plants. But it also needs a lot of care and attention. To help you take care of your rainbow moss, here’s everything you need to know!

For successful growth of rainbow moss, keep it in plastic or glazed ceramic pots with moisture-retaining soil, water it when the top 2 inches of soil is dry, and grow it by northern or eastern windows at 60-87°F and 40% humidity. Feed it liquid fertilizer every month in spring and summer.

You might think the blue coloring in rainbow moss is due to colored cells. But studies have shown this is actually caused by something else! You’ll find out more about this in the article. But first, here’s a detailed summary for you to save and refer to when needed.

Factors	Optimum Requirements
Planter	4–6 inch deep pots made of plastic or glazed ceramic.
Soil	Moisture-retaining mix made of 50% loam soil or coco coir, 20% worm castings, and 20% perlite or pumice.
Water	Water when the top 2 inches of soil is dry. Never let it fully dry.
Light	Grows best in northern or eastern windows with curtains. No more than 2 hours of direct sun daily.
Temperature	60°F to 87°F
Humidity	At least 40%
Fertilizer	General liquid fertilizer every month in spring and summer. Avoid fertilizer in winter

Each of these factors is discussed more in detail underneath, so let’s go over them!

Planter

Grow rainbow moss in non-porous planters like glazed ceramic or plastic pots. Refrain from using terracotta as this will wick away too much moisture. Keep rainbow moss in 4–6 inch deep pots.

Selecting a pot for rainbow moss plants is easy: stay clear of terracotta.

While its orange hue might compliment the foliage of the peacock fern, terracotta is porous. This means that air and moisture freely pass through the pot and dry it out faster.

Instead, consider using plastic. They retain more moisture than terracotta, which this plant needs.

Learn how to customize and Paint Those Plastic Garden Pots The Right Way!

Moreover, plastic pots are easier to turn into hanging pots. The rainbow moss looks best when grown in pots suspended from ceilings.

Glazed ceramic pots are also ideal for water retention.

A simple 4 or 6-inch deep pot with drainage will work just fine, as these plants don’t need large planters.

Soil

Use a high-water retention potting mix with 50% coco coir or soil, 20% perlite or pumice, and 20% worm castings for rainbow moss. Orchid bark can also be added to increase drainage.

Rainbow moss plants hate drying out, so you’ll need good moisture-retaining soil.

I know some folks who grow rainbow moss in 100% regular potting soil. They find it holds just enough moisture for the moss.

But if you plan to keep your plant in a cooler or darker space, you can add more ingredients like orchid bark to increase aeration and prevent them from staying damp too long.

A good blend for rainbow moss can include 50% loam soil or coco coir, 20% perlite, and 20% worm castings for extra nutrition.

Water

Rainbow moss plants require consistent watering regimes and must be watered when the top 2 inches of soil have dried. Avoid letting more than 40% of their substrate dry up.

When it comes to rainbow moss, I rarely hear about them suffering from overwatering. They will happily flourish and grow so long as they’re grown in moist substrates.

How often you water your rainbow moss will depend on your environment. Once the top 2 inches (5.08 cm) of soil feels dry, give it a heavy watering.

Rainbow moss rarely responds well to inconsistent watering. So avoid neglecting to water it so much so that over 40% of its soil has dried out.

You can use this moisture meter from Amazon to know exactly how damp your soil is. It will help you understand when to water!

Self-watering pots might be tempting to use with peacock fern. But this is risky. Using these could underwater or suffocate the plant.

Instead, place them in a place you frequently pass by or stay in to ensure you don’t forget about them. This is important as they’re highly intolerant of drought and neglect.

Light

Rainbow moss is sensitive to direct sunlight and cannot tolerate more than 2 hours of full sun exposure. For optimum growth, give it partial shade by northern or eastern windows indoors. It can also grow outdoors when kept out of the sun.

Its feathery blue leaves might appear man-made. But this is a naturally occurring moss from southern China that can be found in damp and shady areas.

A 2022 study revealed that rainbow moss plants have special leaf structures that allow them to capture different wavelengths of light. As a result, the leaf color deepens and forms a metallic sheen.

To help replicate its natural growing conditions, rainbow moss can be grown in partial shade. It will also be content in a brightly lit room. Just remember to give it no more than 2 hours of direct sunlight daily.

Like me on a hot summer day, it enjoys sitting in bright windows while being kept out of the sun’s direct reach. Northern windows or filtered eastern windows will work best.

Due to its sensitivity to full sun, peacock fern is typically grown indoors. However, if you have a well-shaded porch, you can keep your rainbow moss outdoors.

Temperature

Rainbow moss plants can be grown at 60–87°F. It is slightly hardy and can be grown outdoors but could suffer when temperatures are consistently under 40°F.

The Selaginella uncinata, or rainbow moss, can tolerate a wide range of temperatures.

In fact, it is somewhat hardy and can even be grown outdoors in zone 6a, or Kansas and Missouri.

Find out The 8 Best Plants to Grow in Zones 5a and 5b.

However, it’s not impervious to frost. When temperatures drop below 40°F (5°C), bring it indoors and keep it warm.

The rainbow moss grows well in temperatures between 60–87°F or 15–30°C. It is a semi-evergreen plant.

In other words, it should keep its blue-green sheen so long as you keep it healthy. You’ll learn how to tell whether or not your rainbow moss is healthy later on, so let’s keep going!

Humidity

Although rainbow moss plants can live with humidity levels of around 40%, they will grow faster with higher humidity. Leaf-browning is a sign that it needs higher humidity. Use a humidifier or place the rainbow moss in a bathroom.

As a humidity-loving plant, rainbow moss is widely used in terrariums. More importantly, it develops beautifully with more prominent colors when grown in higher humidity levels.

The good news though, is that it can still be successfully grown with moderate humidity levels of around 40%.

Anything drier than this is not suitable, so consider using a humidifier to boost overall humidity for your peacock fern, as misting does not help.

Club Moss in My Terrarium! and Peacock Fern in the Aquarium/Terrarium - It is Mossy & Ferny Here!

Don’t be alarmed if your new rainbow moss turns brown around the edges. Newly bought rainbow moss plants can sometimes have trouble adjusting to the new humidity.

Help it adjust and acclimate to its new home. Increase the humidity by keeping it in your kitchen or bathroom. I’m sure you’ll appreciate how much it can brighten up these areas too!

Fertilizer

To accommodate for its regular growth, feed rainbow moss plants half-strength liquid fertilizer monthly in the spring and summer. Avoid fertilizing this plant in the winter when it is dormant. Granular fertilizer can also be used.

It doesn’t grow taller than a foot high, but rainbow moss plants love to grow new fronds regularly, especially if they’re happy!

You can use a slow-release granular fertilizer and mix it in its soil. Alternatively, you can give it general liquid fertilizer once a month during spring and summer.

What’s the difference between Liquid vs Granular Fertilizer?

This plant likes to rest and go into dormancy during the winter, so there will be no need to feed it in that season.

If a liquid fertilizer is used, you can give your rainbow moss half-strength fertilizer once a month or whenever you see new growth. Their fronds can be quite delicate and could suffer from higher concentrations of fertilizer. When in doubt, use less.

How to Tell if Your Rainbow Moss is Healthy (Or Not)

Healthy rainbow moss will stay green and regularly grow new leaves. Left neglected, however, it will become unhealthy and turn brown or yellow. If more than 40% of its foliage is discolored and its soil is dry, the plant is dehydrated and needs water immediately.

The easiest way to tell if your rainbow moss is healthy is when it’s vibrant all over and pushing out new growth.

You might feel worried whenever you see some of its leaves die, but such turnover is normal! Remove these dead fronds to prevent them from blocking new growth.

It is common for the bottom leaves of rainbow moss to turn brown and die. But if more than 40% of the plant is affected, this could be a sign the plant is dying.

Common signs of underwatering in Selaginella uncinata are very dry soil and brown or yellow leaves. You’ll have to respond quickly by watering them immediately, as rainbow moss can be quite fragile without water.

To be frank, this plant can be hard to maintain. Their thin and soft leaves need regular care and attention that some can’t consistently provide.

But if you provide regular water, moderate to high humidity, and keep it out of the sun, your rainbow moss will stay vibrant and healthy in your home for years!

FAQs

What is rainbow moss?

Rainbow moss or blue spike moss is a plant native to southern China. Although it has fern-like foliage, it is botanically classified as moss because it tends to spread and hug the ground. Its metallic sheen helped it earn the name “rainbow moss” as it often looks blue or sometimes purple.

Why is my rainbow moss turning white?

Rainbow moss plants typically become pinkish-white when they are suffering from sun stress or low humidity. This plant cannot stand more than 2 hours of direct sunlight and is best grown in partial shade. Grow rainbow moss with humidity levels around 40% to ensure its foliage stays green.

Is rainbow moss toxic?

The rainbow moss plant is non-toxic to animals and humans. It can safely be grown indoors but can be kept in hanging pots to prevent pets like cats and children from ingesting or destroying it.

Summary of How to Care for Rainbow Moss

Rainbow moss can be hard to maintain due to its very specific growing needs. It must be kept in non-porous pots, like plastic or glazed ceramic, filled with moisture-retaining soil. It must never be allowed to fully dry. Rainbow fern must be watered once the top 2 inches of soil is dry.

Grow rainbow moss indoors by northern or eastern windows or outdoors in partial shade—receiving no more than 2 hours of direct sunlight. Keep them at 60–87°F and 40% humidity. Only provide liquid fertilizer every month in spring and summer.

A healthy rainbow moss can be identified by its consistent growing habit and vibrant color. Conversely, an unhealthy or dying rainbow moss will turn yellow or brown due to underwatering. Revive it by watering immediately.

Sources

• “Selaginella uncinata” by n/a in NC State University
• “Selaginella uncinata” by n/a in University of Florida
• “Anatomical and Biochemical Traits Related to Blue Leaf Coloration of Selaginella uncinata” by Lin Li, Lulu Yang, Aihua Qin, Fangyi Jiang, Limei Chen, and Rongyan Deng in Guangxi University