Learn the most important ventilation rules of your greenhouse, applicable from spring to autumn.
Spring
In early spring, when the temperature is still low (around 5 ° C), solariums are kept closed to maintain the heat in the interior and to achieve a temperature with 6-10ºC higher than the one from the outside. During this period, ventilation can only be done when the internal temperature reaches 25ºC and tends to increase (usually in sunny days), around 10 o’clock.
If the greenhouse has dung as a heating source or if there is a box of manure compost inside the greenhouse, which releases carbon dioxide and ammonia, ventilation must be done on cloudy days.
As the weather warms and the indoor temperature tends to exceed 25ºC, it is recommended airing on sunny days, from the greenhouse’s ends, between 10-16 o’clock. It is necessary to shut the greenhouse at 16.00 o’clock to accumulate some extra heat required in the nights where temperatures can drop below 0ºC.
Summer
Starting June, when the outside temperature doesn’t fall below 20 ° C, the greenhouse remains open day and night.
Also, starting this month, the ventilation is done from the sides too, by raising the foothills.
If the indoor temperature exceeds 28-30ºC during the day, it is necessary a roof ventilation.
Autumn
In autumn the temperature drops below 20 ° C overnight and you need to shut the greenhouse again. The ventilation is done only if it’s absolutely necessary.
In cold and windy days, in spring and autumn, the greenhouse is kept shut. If the temperature inside the greenhouse tends to exceed 25ºC, the ventilation will be done through the leeward door.
Image Credits: Farmhack