Making the Most of Your Greenhouse in January
The arrival of winter doesn’t mean your gardening journey has to pause. With a greenhouse, you can continue growing various crops throughout the coldest months while enjoying the therapeutic benefits of gardening year-round. This guide will help you maximise your greenhouse’s potential during winter, from what to grow to essential maintenance tips.
Benefits of Winter Greenhouse Gardening
Winter greenhouse gardening offers several advantages:
- Provides a comfortable environment for year-round gardening
- Ensures a steady supply of home-grown produce for spring
- Helps maintain active engagement with gardening during darker months
- Contributes to positive mental health during winter
- Offers a head start on spring growing
Essential Winter Greenhouse Management
Temperature Control
Maintaining a frost-free environment is crucial for winter growing success. Consider these options:
- Install electric heaters with thermostatic control
- Use horticultural bubble wrap for insulation, particularly on the roof and end panels
- Pre-heat the space before working for personal comfort
- If electricity isn’t available, consider using a paraffin heater as an alternative
Ventilation
Despite the cold, proper ventilation remains essential:
- Open doors on bright mornings
- Close before sunset to retain heat
- Maintain good airflow to prevent mildew and disease
- Balance ventilation with heat retention
What to Grow in Your January Greenhouse
Vegetables
- Early Potatoes
- Plant in large buckets or grow sacks
- Start in January for March harvest
- Use two parts garden soil to one part compost
- Leafy Greens
- Winter lettuce varieties (Little Gem, Rocket, Lamb’s Lettuce)
- Spinach and Kale (can survive temperatures as low as -6°C)
- Pak Choi (30 days for leaves, 70 days for full plant)
- Brassicas
- Brussels Sprouts (harvest when 1-2 inches in diameter)
- Cabbage and Broccoli (start mid-winter for spring planting)
- Cauliflowers (for early summer harvest)
- Root Vegetables
- Carrots (Early Nantes and Amsterdam Forcing varieties)
- Salad onions
- Leeks (sow in deep troughs)
- Legumes
- Broad beans (start in 7.5cm pots)
- Early peas (consider using guttering method)
Herbs
Several herbs thrive in winter greenhouse conditions:
- Coriander
- Dill
- Mint
- Parsley (particularly cold-hardy)
- Mediterranean herbs (thyme, sage) from summer cuttings
Additional Crops
- Microgreens (year-round harvesting)
- Mixed salad leaves (sow weekly for continuous crops)
- Garlic and shallots (start in pots for spring planting)
Tips for Success
- Be Patient: Winter growth is naturally slower due to shorter daylight hours, particularly around the winter solstice.
- Choose Appropriate Varieties: Always check seed packets for winter suitability.
- Maintain Good Ergonomics: Set up your workspace comfortably with proper seating and working heights.
- Practice Succession Planting: Stagger sowings of quick-growing crops like salad leaves for continuous harvests.
- Monitor Conditions: Regular checking of temperature, ventilation, and plant health is essential.
Remember, while growth may be slower in winter, your greenhouse can remain productive throughout the year with proper planning and care. The effort you put in during winter will reward you with early harvests and strong plants ready for spring.