The thought of winter can bring a mix of emotions for a gardener—a longing for the days of growth, but also a worry about how to protect the space and plants you’ve worked so hard to cultivate.
Preparing your greenhouse for the colder months doesn’t have to be a daunting task. By understanding the basics of how a greenhouse works in winter, you can take control. This simple, step-by-step winter greenhouse checklist is designed to give you peace of mind and ensure your gardening haven weathers the season with grace.
A checklist for a confident winter season
Following this guide will help you create a safe, clean, and secure environment for your greenhouse and its contents. By taking a few preventative steps now, you can feel confident that your plants are protected and your structure is sound, leaving you free to enjoy the unique joys of winter gardening.
Step 1: Clean and sanitize your space
A clean greenhouse is a healthy greenhouse. Starting fresh for winter is one of the best things you can do to prevent problems down the line.
- Start with a Deep Clean: Remove all old plant debris, empty pots, and tools from inside. Sweep the floors and wipe down the benches and shelving. This removes places where pests and diseases can hide.
- Sanitize to Prevent Disease: Use a mild soap and water solution or a diluted bleach solution (1 part bleach to 9 parts water) to wash down all non-porous surfaces. Don’t forget to clean the glass or polycarbonate glazing itself, both inside and out, to maximize sunlight.
Step 2: Inspect and repair the structure
The integrity of your greenhouse’s structure is its best defense against winter’s harsh elements. A thorough inspection is crucial.
- Seal Gaps and Cracks: Check for any openings around the foundation, frame, and door that could let cold air in. Seal them with silicone sealant or weatherstripping. This simple step can dramatically improve heat retention.
- Check Your Glazing: Examine all glass or polycarbonate panels for cracks or damage. Replace any broken panes or patch small cracks with a clear sealant. A strong, intact seal is vital for both heat retention and safety.
- Reinforce the Frame: Check all bolts, screws, and joints on the frame. Tighten anything that feels loose. This ensures the structure can handle the weight of snow and withstand strong winter winds.
- Check Doors and Vents: Make sure your door seals tightly and that all automatic vent openers are in good working order. If you’re not using your vents, you can secure them shut for the season.
Step 3: Organize and prepare the interior
Once the outside is secure, you can focus on creating the best possible environment inside for your plants.
- Prepare Your Plants: Before bringing plants indoors, inspect them for pests and diseases. Trim back any dead or damaged foliage. Group plants together by their needs—some may need more light, while others are simply overwintering and require minimal care.
- Organize Your Benches and Paths: Arrange your benches and plants to maximize sunlight exposure. Use your benches for plants that need the most light, and keep walkways clear for easy access and air circulation.
Step 4: Plan for heating and insulation
Even if you plan to keep your greenhouse unheated, taking steps to boost its efficiency can make a big difference.
- Assess Your Heating Needs: Decide whether you want to heat your greenhouse to protect tender plants or simply allow it to function as a large cold frame. Your choice will guide your next steps. If you choose to add warmth, our collection of heaters for greenhouses offers a range of reliable options to fit your needs. To ensure you select the right size, you can use our handy greenhouse heater calculator.
- Insulate for Efficiency: Consider adding a layer of bubble wrap or horticultural fleece to the inside of your glazing to create extra insulation. This is a very effective and inexpensive way to hold in precious heat and protect plants from nighttime temperature drops. For more in-depth advice, you can explore various DIY ways to insulate and heat your greenhouse.
Step 5: Final winter preparations
Your greenhouse is almost ready. These final touches will ensure everything is buttoned up and protected for the long haul.
- Clear the Area Around the Greenhouse: Remove any dead leaves, tools, or other debris from the area immediately surrounding your greenhouse. This helps prevent pests from overwintering and ensures you can easily get to the greenhouse door without slipping.
- Prepare a Snow Removal Plan: Have a broom or soft rake ready to gently brush off heavy snow from the roof and sides. While your greenhouse is built to be strong, preventing snow buildup is a key step in protecting its structure over time.
