Table of Contents
Ferns are a popular choice for gardeners seeking lush greenery and a touch of the wild in their landscapes. However, many fern varieties are sensitive to cold temperatures and require special protection during winter months. One effective solution is building a cold frame—an outdoor shelter that provides insulation and shields ferns from harsh weather.
Understanding Cold Frames
A cold frame is a transparent-roofed enclosure that creates a microclimate, trapping heat and protecting plants from wind, frost, and snow. It is typically made from wood or metal with glass or plastic panels. Cold frames are ideal for overwintering ferns, allowing them to survive cold spells and emerge healthy in spring.
Materials Needed
- Wooden pallets or lumber
- Glass or clear plastic panels
- Hinges and latches
- Insulation material (optional)
- Soil and compost
- Fern plants
Steps to Build a Cold Frame for Ferns
Step 1: Choose a Location
Select a spot that receives partial sunlight and is sheltered from strong winds. Ensure the ground is level and well-drained to prevent water accumulation around the base.
Step 2: Construct the Frame
Use wooden pallets or lumber to build a rectangular frame. The size should accommodate your fern collection comfortably. Secure the corners with nails or screws for stability.
Step 3: Install the Cover
Attach glass or clear plastic panels to the top of the frame using hinges for easy access. Seal the edges with weatherproof caulk to prevent drafts. Consider adding a latch to keep the cover secure during storms.
Enhancing the Cold Frame
To improve insulation, line the interior with bubble wrap or foam panels. Add a layer of mulch or straw at the base to retain heat and moisture. Regularly ventilate the cold frame on warmer days to prevent excess humidity and mold growth.
Caring for Ferns in the Cold Frame
Monitor the temperature inside the cold frame regularly. Ferns prefer moist, cool conditions, so water them as needed, avoiding overwatering. Remove any snow accumulation from the cover to maintain light and airflow.
Common Fern Varieties for Cold Frames
- Maidenhair Fern (Adiantum spp.)
- Christmas Fern (Polystichum acrostichoides)
- Ostrich Fern (Matteuccia struthiopteris)
- Lady Fern (Athyrium filix-femina)
These varieties are hardy and can tolerate cooler temperatures when protected properly.
Conclusion
Building a cold frame is an effective way to safeguard your ferns during winter. With proper construction and care, your ferns will thrive in their sheltered environment, emerging vibrant and healthy when spring arrives. Enjoy nurturing your lush green sanctuary year-round.