Ventilation in Greenhouses is essential for maintaining healthy growing conditions.

A lack of ventilation can lead to damp humid conditions which encourages fungal diseases like botrytis and plants can get overheated. Plants have an optimum temperature which varies considerably depending on the type, so it is a good idea to check out the requirements of what you are growing and manage the temperature accordingly.

Having too high a temperature is just as bad as having too low a temperature. A rule of thumb for Glasshouses is that the area of the vents should amount to a minimum of 15% of the floor area, the more the better. So for example if your Greenhouse is 20 sqm you should have at least 3 sqm of vents.

It is best to have a combination of roof and side vents to encourage convection – the natural flow of air. Louvre vents (small slats that rotate) provide more ventilation than top hinged side windows.