Many gardeners mistakenly believe that once summer arrives, the greenhouse becomes useless. In spring, seedlings are moved to open beds, and the structure often sits idle. But with the right approach, a greenhouse can become a powerful ally during the summer — protecting your plants from unpredictable weather, extending the growing season, and even giving you a chance to experiment with new crops.
Why Use Your Greenhouse in the Summer?
Summer weather can be deceiving: sunny and warm one day, rainy and cool the next. Sudden temperature drops, cold nights, or even hail can wreak havoc on your garden. In contrast, a greenhouse offers a stable, controlled environment that reduces plant stress and encourages healthy growth. This is especially helpful in regions with short or unpredictable summers.
How to Keep Your Greenhouse Cool and Humid
Ventilation is Key
To prevent overheating and condensation, your greenhouse should have proper airflow. This means doors at both ends and vents on the sides and roof. From mid-June through August, keep the doors open 24/7 unless there’s strong wind or heavy rain. Good air circulation helps maintain a comfortable microclimate for your plants.
Watering & Heat Retention
Water your plants in the morning to avoid fungal diseases. Place a large, dark-colored barrel (50–55 gallons) filled with water inside the greenhouse. During the day, it absorbs heat and releases it at night, helping to regulate temperature and humidity.
Natural Ways to Cool Down Your Greenhouse
Live Shade: Beautiful and Functional
Plant tall crops like beans, corn, peas, grapes, or raspberries around the greenhouse perimeter. They’ll provide natural shading and give you a bonus harvest. A living screen is a great eco-friendly way to reduce heat and beautify your garden space.
Shade Cloths & Reflective Nets
Use UV-stabilized shade cloths (ideally with 40–50% light transmission) to reflect sunlight and cool down the interior. These nets can also protect against hail, birds, and insects. Hang them just above the greenhouse rather than laying them flat for better airflow and heat deflection.
Spunbond Fabric: A Smart Alternative
Spunbond is a lightweight, breathable fabric made of polypropylene. It diffuses sunlight, protects against extreme heat and cold, and allows airflow and moisture to pass through. It’s affordable, easy to use, and doesn’t require much maintenance — perfect for busy gardeners.
What to Grow in a Summer Greenhouse
Summer is ideal for growing fresh greens and fast-growing crops that thrive in a controlled environment. You can harvest many of them continuously throughout the season.
Leafy greens:
- lettuce,
- dill,
- parsley,
- green onions,
- spinach, basil, cilantro.
Vegetables:
- cucumbers,
- tomatoes,
- radishes,
- peppers,
- eggplants.
Berries and melons:
- strawberries,
- raspberries,
- watermelons,
- cantaloupes.
If you create a shaded corner inside the greenhouse, you can even try growing mushrooms — like oyster or button mushrooms. It’s a fun project and a great way to diversify your harvest.
Pro Tips from Experienced Gardeners
- Mulch generously: helps retain moisture and cool the soil.
- Install drip irrigation: conserves water and keeps roots cool.
- Monitor for pests: greenhouses can attract bugs if not regularly checked.
- Be bold: summer is the perfect time to test new plant varieties or unusual crops.
