Summer is well and truly in full swing, and for many readers that means plenty of time in the garden. If you have a greenhouse, however, it pays to put in some extra work and gear it out for summer – whether it is made of plastic or glass, the plants inside are very vulnerable to overheating from the extra heat and sun during these months. Although some perennials will be fine, save your plants from damage by ensuring they have adequate shade, moisture, and cooling. Here’s a quick guide to prepping your greenhouse for warmer weather.
Measure Your Weather
A good rule of thumb is that most plants will thrive at room temperature – approximately 20-24 degrees centigrade. And of course, a greenhouse is the best way to ensure this. However, during warmer weather or just more changeable weather, it can be hard to maintain the correct temperature inside. Many garden centres offer a range of temperature and weather forecast products which can be remotely accessed from a smartphone or with a monitor kept indoors, so you can keep an eye on everything. Take advantage of any rainy days with a water butt, from which you can fill your can to keep your greenhouse plants hydrated.
Automatic Ventilation Windows
It’s unrealistic to expect a normal home gardener to rush to the aid of their greenhouse plants when they overheat, and fortunately automatic ventilation products are available for greenhouses. These are very easy to install by yourself at home – just be sure you can test that the vent opens far enough before leaving it to its own devices. Automatic vents are ideal for days when you can’t be at home, and allow you to set a timer to open during the hottest parts of the day, changing with the seasons. For extra hot forecasts, it can be helpful to put a small electric fan in the greenhouse as well to get some extra breeze.
The greenhouse walls will magnify the sunlight that is let in, so it’s worth investing in some shading if your garden is particularly sunny to minimise damage. The RHS advise that shading is usually necessary from mid-spring to early autumn, unless you are growing hardy edible plants such as tomatoes. There are many types of shading to choose from, but external blinds are usually the best as they prevent the glass walls from absorbing too much heat. The cheapest method of doing this is fixing sheets of polyethylene mesh material either over or under the roof and held with clips or clothesline pegs, making it easy to adjust and remove the amount of shade where needed.