Keeping your greenhouse cool in summer is essential, as high temperatures can cause heat stress, damaging your plants and potentially, your crops.
Damping down and providing shading in the form of blinds, screens and shading paint can help, and it's really important to encourage good air circulation by opening the doors and vents.
You can make sure your greenhouse ventilation is constantly regulated during hot summer months, whether you're at home or not, by installing an automatic vent opener. It contains a wax that expands when heated, opening the vent. When the temperature falls, the wax contracts and the vent closes.
UPVC greenhouses have lightweight roof vents and may require a stronger vent opener to keep them closed or prevent them being blown away - check before you buy.
Available at garden centres or online, automatic vent openers are quick and easy to install - here's how to do it.