1. Begin with a Thorough Clean

• Remove spent growth and waste: Remove spent plants, fallen leaves and waste that may harbour pests or disease.
• Clean every surface: Wash walls, glazing and work surfaces with warm soapy water.
• Check for pests: Inspect the greenhouse for insects or pests and deal with any infestation promptly.

2. Inspect and Repair

• Look for cracks and gaps: Examine frames, panels and seals for any damage.
• Strengthen weak areas: Repair or reinforce loose joints and damaged panels.
• Renew cracked panes: Fit new glass or polycarbonate panels wherever breakage could let warmth escape.

3. Improve Insulation

• Add horticultural bubble insulation: Fix purpose-made bubble material to the inside surfaces.
• Stop draughts around openings: Apply draught-proofing strips at doors and ventilators.
• Fit a thermal curtain: This adds insulation, particularly in larger greenhouses.

4. Ensure Effective Heating

• Install a heater: Choose from electric, gas-fired or paraffin greenhouse heaters.
• Control heat thermostatically: Set it to maintain the chosen temperature.
• Make the most of sunshine: Keep glazing clean to maximise available daylight and solar warmth.

5. Improve Ventilation

• Fit self-opening vents: Automatic opening moderates heat and moisture levels.
• Circulate air with fans: Moving air spreads warmth evenly and discourages mould.

6. Grow Winter Vegetables

• Rotate crops: It limits diseases carried in the soil.
• Choose raised beds: They offer roots extra protection from cold conditions.

7. Give Plants Extra Shelter

• Cover tender specimens: Use horticultural fleece or cloches during cold spells.
• Group plants together: A small microclimate can help retain warmth.
• Avoid overwatering: It helps prevent root rot.

8. Review Supplementary Lighting

• Add lighting where needed: LED or fluorescent lamps can extend limited natural daylight.
• Position lights well: Ensure even coverage for healthy plant growth.

9. Put Tools and Supplies in Order

• Prepare equipment before storage: Keep sharp, clean tools in a dry place.
• Top up supplies: Keep seeds, fertiliser and appropriate pest-control supplies ready.

10. Consider Winter Equipment

• Guard against snow: Limit excessive snow build-up across the greenhouse roof.
• Seedling heat mats: They can support seed germination.
• Use cold frames: They provide extra insulation inside the greenhouse.

11. Maintain Regularly

• Track the growing environment: Keep a thermometer and hygrometer in the greenhouse.
• Remove snow: Clear settled snow to reduce the risk of structural damage.
• Reduce condensation: Wipe down surfaces regularly.

12. Prepare for Disruptions

• Power-cut provision: Have a generator available if electricity fails.
• Spare insulation: Keep additional bubble wrap within reach.