Glasshouse drainage is an essential part of greenhouse management.
Water is vital to growing plants. It is delivered either by sprinklers or irrigation. In a perfect world, plants would absorb all that they were given; but as the world isn’t perfect, there’s nearly always not enough or too much.
When there’s too much, the excess has to go somewhere. And that’s where drainage comes in. It helps to preserve the balance between what is needed and what is left over.
To look at the state of some greenhouses, you’d think that the mud that excess water can create wasn’t a problem; but it is. It makes surfaces unnecessarily messy and even dangerous for workers and provides the perfect environment for disease.
Not all drainage originates on the floor. You also have to think about the roof. This is where gutters come in handy. They enable you to direct the extra water to a particular spot, rather than simply letting it run down the sides of your glasshouse.
This is particularly important because rainfall intensity has increased in the past 100 years. This is more noticeable during the winter, but it also occurs in the spring and autumn. A typical downpour of even just a couple of minutes can dump 15mm on one spot – you – in an hour.