Ventilation techniques

Ventilate the greenhouse to keep day temperatures down and to introduce a gentle air flow. Roof vents can be fitted with automatic openers that open at about 20°C but if not, prop them open and open side louvres or doors. Air flow can have a drying effect on plants so your plants might need more water.

Night temperatures can still be low now, so shut vents in the evening and watch the forecast. A max/min thermometer will guide you on the typical temperatures in the house.

Keep air flowing in the greenhouse to avoid humidity causing disease