The Frosty Fern (Pteris ensiformis ‘Evergemiensis’) is a striking houseplant prized for its delicate appearance. It is often called the Silver Lace Fern due to its lacy, arching fronds that feature silvery-white variegation down the center of each leaflet. This distinct coloring creates a “frosted” effect, making the plant a popular choice for adding texture to indoor spaces. Its graceful foliage makes it an elegant addition to any home, provided its specific tropical requirements for moisture and light are met.
Providing the Right Environment
The delicate foliage of this plant is sensitive to harsh light, requiring bright, indirect light to thrive indoors. Placing it near an east-facing window or a few feet away from a south or west-facing window is ideal. Direct, intense sunlight will quickly scorch the variegated tips, leaving them brown and damaged.
If light levels are too low, the plant’s growth may become sparse, and the signature white variegation can fade. The ideal ambient temperature for this fern is consistently between 60°F and 75°F (15°C to 24°C). Avoid placement near exterior doors, cold drafts, or heating and air conditioning vents, as sudden temperature fluctuations can stress the plant.
Watering and Humidity Management
The Frosty Fern requires consistent soil moisture and will not tolerate drying out. The goal is to maintain soil that is evenly moist but never saturated or waterlogged, which can lead to root rot. To check the moisture level, insert a finger about an inch into the soil and water thoroughly once the surface begins to feel slightly dry.
When watering, ensure the pot has drainage holes so excess water can escape immediately. Distilled water, filtered water, or rainwater is preferred over tap water, which often contains minerals and salts. These accumulated minerals can build up in the soil and potentially cause leaf tip burn on the sensitive foliage.
Humidity is the most demanding aspect of the Frosty Fern’s care, as it naturally thrives in a high-moisture environment, ideally between 60% and 90% relative humidity. In a typical home, this moisture level must be supplemented, especially during winter when forced-air heating reduces ambient humidity. The most effective way to provide this is by using a small cool-mist humidifier placed nearby.
Grouping the fern with other plants creates a microclimate that naturally increases localized humidity levels. A simple pebble tray filled with water can also be placed beneath the pot, ensuring the pot rests on the pebbles above the waterline. Failing to provide sufficient humidity will cause the plant’s delicate fronds to develop dry, crispy, and brown edges.
Feeding and Soil Requirements
The Frosty Fern is a light feeder and does not require frequent or heavy fertilizer applications. Over-fertilizing can easily damage the shallow root system, leading to leaf burn or decline. Apply a balanced, water-soluble liquid houseplant fertilizer only during the active growing season (spring through early fall). Dilute the fertilizer to half or quarter strength of the manufacturer’s recommendation to prevent nutrient overload. Fertilizing once every four to eight weeks is sufficient to support healthy growth.
The plant thrives in an airy, well-draining, and moisture-retentive potting mix rich in organic matter. A peat-based mix amended with materials like perlite or vermiculite provides the necessary balance of aeration and moisture retention. The pot must always have adequate drainage holes to prevent the soil from becoming dense and soggy. Repotting is generally only necessary every one to two years, as this fern has a relatively slow growth rate.
Identifying and Addressing Care Issues
Observing the foliage is the best way to determine if the plant’s environmental needs are being met. Brown, crispy tips or edges on the fronds are the most common sign of insufficient humidity or inconsistent watering. Correct this by increasing ambient humidity or establishing a more reliable watering schedule. Yellowing leaves, particularly on older growth, often signal overwatering, which can lead to root rot. If this occurs, check soil saturation and allow the top layer to dry out slightly before the next watering. Pale, bleached, or washed-out fronds indicate the plant is receiving too much direct light.
Like most indoor plants, the Frosty Fern can occasionally attract common houseplant pests such as spider mites, mealybugs, or scale. Inspect the undersides of the fronds regularly for signs of infestation. Minor outbreaks can often be controlled by gently wiping the foliage with a soft cloth or a cotton swab dipped in insecticidal soap.