IF you’re lucky enough to own a greenhouse, chances are it is packed to the rafters with all manner of edible goodies now. But heatwaves and thundery deluges, along with pest and disease attacks, can all make life tricky, so let me guide you towards safety under glass.
Overheating can pose a real threat to your crops. Most plants stop growing when the temperature reaches 32ºC (90ºF), and that can easily happen under glass on sunny days, when the temperature outside is in the mid-20°C. Fruit set and formation can also be hindered, leading to malformed or absent fruits on crops such as tomatoes, melons and cucumbers.
Thwart overheating by addressing basic issues – installing sufficient roof vents (20% of the floor surface area is ideal), leaving doors open during scorching-hot days, ensuring water butts plus downpipes are in good working order, and damping
