Selaginella Kraussiana & Selaginella Martensii – Frosty Fern Care

Selaginella kraussiana ‘variegata’ (and its cousin varieties) are Christmas plants that are also known as frosty ferns. They are relative newcomers to the holiday plant scene, and popular because of their lightly frosted white tips.

If you are bored with the tried and true plants for Christmas, such as amaryllis, Christmas cactus and poinsettia, try growing frosty fern this year.

The plant is a bit finicky to grow indoors. These growing tips for frosty fern care will help you get the most out of your new plant.

Selaginella kraussiana is a low-growing plant which forms mats. It has fern-like leaves, and spreads by way of rooting stems.

The plant requires a minimum temperature of 41 °F (5 °C) to grow outdoors and in cooler areas, is often grown as a dense ground cover in terrariums, or as a houseplant for the holidays. It also makes a great dish garden plant, or container plant.

Facts about frosty fern

Frosty fern isn’t actually a fern at all! It is a variety of spike moss, and surprisingly, not really a moss either. If you are confused at this point, join the club!

Even though it is referred to as either both a fern and a moss, this naming is based on its appearance rather than its taxonomy. Frosty ferns are a type of spike moss. Unlike true mosses, spike mosses have roots and leaves.

Brush up on your knowledge of frosty fern with these facts:

• botanical name – selaginella kraussiana and other spp.
• family – selaginellaceae
• type – evergreen tender perennial
• native to – found naturally in South and East Africa and Macaronesia.
• common names – frosty fern, frosted fern, Krauss’ spike moss, Krauss’ clubmoss, African clubmoss, cushion moss, spreading club moss, trailing moss

Selaginella varieties – which is the Christmas frosty fern?

Not only is the taxonomy confusing, the common name of the plant itself can be.

The potted plant called frosty fern which is sold as a Christmas plant is most likely to be Selaginella martensii, a slightly taller variety of selaginella. Another variety with white tips but a  lower growing jabot called Selaginella kraussiana ‘Variegata’.

A third variety which has white tips and also has the common name frosty fern is Selaginella kraussiana ‘Aurea’.

Selaginella kraussiana ‘Variegata’ and Selaginella kraussiana ‘Aurea’ grow about 1-2 inches high and spread easily as  groundcovers or trailing plants. They have bright green leaves with white tips.

On the other hand Selanginella martensii is a small bushy plant that grows about 7-9” tall and wide and is not so invasive in growth.

No matter the variety you purchase, this pretty plant with its white growing tips reminds us of a winter wonderland!

If you are looking for an interesting new plant to display for the holidays, frosty fern is a great choice.

Note: Since frosty fern often appears for sale at Christmas, many people refer to it as a Christmas fern. This is not correct, though, the Christmas fern (Polystichum acrostichoides) is an actual fern which is a different plant altogether.

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How to grow selaginella varieties

Selaginella kraussiana and its cousins martensii and aurea are cultivated for ornamental uses. The plants require high humidity and indirect lighting to flourish indoors.

Even though these spike mosses are often seen for sale as a holiday plant, they actually have a hard time growing in the average home. Many time, the plants will start to quickly die after you bring them home.

These frosty fern plant care tips will give more detail about how to grow the spike moss and keep it alive in your home.

Sunlight needs for selaginella kraussiana

Give frosty fern bright, indirect light to part shade. It does not like more than 2 hours of sun a day. Direct sunlight can easily scorch its foliage.

Do not place closer than two feet to a south facing window. Since this plant likes lower light conditions, a north facing window is fine.

Watering requirements for frosty fern

Water selaginella kraussiana with room temperature water if possible. Cold water can shock the plant.

The plant is not a fan of lime or hard water. Rainwater and distilled water are best for watering purposes.

Reduce watering by one-half during the fall and winter since the plant is not actively growing at this time.

Fertilizing and soil needs for selaginella kraussiana

Plant frosty fern in a clay-like soil that has been amended with compost or other organic matter. Be sure the soil drains well.

Water to keep the soil consistently moist. Fertilize once a month during the growing season (spring through fall) using a balanced fertilizer at 1/2 strength.

Be careful of over-fertilizing. Too much nitrogen can turn the white tips green.

The ideal pH is neutral to slightly acidic. A soil pH of around 6 – 6.8 yields good results.

Frosty Ferns need humidity

Dry air will cause the leaves to turn brown and shrivel. The plant like tropical conditions and loves humidity.

A humidity level of above 70% is ideal, which most homes do not have. This is why people often grow the plant in terrariums. 

Since bathrooms have a higher humidity than other rooms in the home, growing your frosty fern in a bathroom is ideal.

To raise the humidity to the level that the plant needs, place frosty fern among other plants. The humidity around a plant grouping is higher than plants grown alone. 

Growing selaginella kraussiana in a terrarium or place the plant on a humidity tray with pebbles sitting in water will raise the humidity level for the plant. 

Cold hardiness for selaginella kraussiana

Frosty fern is considered a tender perennial. The ideal temperature indoors is 65-75°F (18-24°C). Keep away from open drafts.

The plant will not survive the winter if temperatures go lower than 41 °F (5 °C). It is cold hardy only in zones 11b and above.

Flowers and foliage of selaginella kraussiana

Frosty fern gets its common name from the distinctive white color of its new growth. This gives the tips of the leaves a frosted appearance that is reminiscent of snow.

It has a mounding habit that is made up of creeping stems that spread quickly. Selaginella kraussiana adds a nice texture to any plant grouping. 

The mounding variety is very low growing, reaching only about 4 inches in height in most homes, Under ideal conditions, it can reach 1 foot tall.

The normal selaginella kraussiana grows to only about 2 inches tall but it spreads a lot, which makes it ideal as a ground cover. 

Don’t be too concerned if your frosty fern loses its frosted tips in the summer months. This happens when daytime temperatures are too hot. The frosting will return when the temperatures drop in the fall.

Propagating frosty fern

Get new plants for free by propagating spike moss from stem cuttings. The plant will grow best indoors if you trim it back to control its rapid spread.

Keep the cuttings, since they will root easily. 

The plant is also propagated by division of the low-growing mats. If you are an advanced gardener, you may have luck growing frosty fern from the spores which are produced.

Pests and diseases for spike moss

Krauss’ spikemoss is generally disease and pest-free. Since the plant likes to be consistently moist, be on the look-out for crown rot from too much watering.

The most common problem that home gardeners experience growing frosty fern is dry leaves and a dying plant from lack of humidity.

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Is /selaginella kraussiana poisonous?

Many houseplants are toxic to children and pets. Fortunately, frosty fern is considered pet-safe.

The ASPCA lists selaginella kraussiana as non toxic to cats, dogs and horses. That means your kitty won’t get an upset stomach if he or she decides to nibble on the leaves.

Where to buy frosty fern

Check out your local Lowe’s, Home Depot and Walmart stores around Christmas time. I sometimes see the plant for sale for the holidays.

Another place to check is your local Farmer’s Market or small local nurseries to see if they have it in stock.

If you cannot find one locally, there are many places online to find selaginella kraussiana for sale.

• Buy selaginella varieties on Etsy
• Find frosty fern on Amazon
• Garden Goods Direct has frosty ferns for sale

Pin these frosty fern care tips for later

Would you like a reminder of this post for how to grow this pretty Christmas plant?  Just pin this image to one of your Pinterest gardening boards so that you can easily find it later.

You can also watch our video on YouTube.

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