Frequent talk of global warming means there is heightened awareness of the weather these days. Where once a cold spring was just that, now it is indicative of a general trend and we start to imagine that every spring will be cold, every winter unbearable, every summer scorchingly hot or preposterously rainy. The truth is that every year is different and British weather is always unpredictable.
Climate and weather
Even if the climate is gradually changing, you wouldn’t really notice from one year to the next. There is too much variation. Climate is only something you can only gauge over a prolonged period of many years.
But weather can be a problem. Ask any gardener. They know only too well that the elements can conspire against them, undoing hours of hard work at a stroke. The experienced gardener knows that an unseasonably warm spell of weather in March does not mean there won’t be later frosts. Move overwintering plants outdoors too early and lush new growth may be frozen solid. Similarly, every gardener fears the sudden onset of strong winds which can decimate plants, breaking stems and knocking things over.
Preparing for unpredictable weather
Fortunately, there are things that you can do to protect your plants from the vagaries of the weather. Growing things under glass is one very popular solution. Whether this is a greenhouse or a polytunnel doesn’t really matter. It is about creating a safer, more controllable environment in which to raise plants when the weather could otherwise intervene.
Strong winds, heavy rains, sudden cold spells – the impact of all of these things can be offset by growing under glass. The effects will be felt most keenly in the spring when plants are just starting to grow and this is when the impact of a greenhouse or polytunnel is felt most strongly.
Photo source: http://www.flickr.com/photos/loozrboy/4161130243/
We have had a particularly cold spring this year, but it is important to note that the amount of light remains the same. You might think light brings heat, but while that is generally true, it depends where the weather is coming from. The difference in atmospheric temperature between areas to the east and west of us is significant as the land of the continent is generally much colder than the sea until early summer when that balance is reversed. Sunlight cannot overcome this in an instant, which is why some days are warmer than others and why we occasionally have very cold or hot spells.
However, the atmosphere inside a greenhouse or polytunnel is static. It is trapped by the glass and therefore the effect of the sun is greater. The effects are compounded by the impact of solar gain, whereby the air inside is liable to heat up and heat up without being able to escape. The effect of this for gardeners is that plants kept under glass are safe from winds and the vagaries of the weather. They will get as much light as ever and much warmer temperatures regardless of where the weather is coming from. This basically equates to more successful gardening.
After several years of stunted growth and wind damage for his plants, Andrew Morecambe has decided to get in touch with First Tunnels.