Why are there Changes to Your Garden Growing Season?

red roses, white roses, pink roses in the walled garden, brockwell park, Lambeth


If the garden growing season in the UK has increased over the last decade, does that mean we’ll have bigger pumpkins, more fragrant flowers or just more snails and aphids?


Let’s start with a definition of what a ‘growing season’ is in relation to your garden and the plants you would like to grow as an amateur gardener.


The garden growing season refers to the period of the year in which climate conditions are optimal – most favourable – for the successful growing of edible plants and ornamentals (flowers and shrubs).


Depending where in the world you garden, the growing season will vary, as will the method of establishing its duration.

In other words, a useful general definition for those gardening in temperate zones would be that the garden growing season may be defined as being the weeks and months between the last frost in early spring to the first frost in the autumn.

espresso coffee cup

I garden in a temperate zone, but as a coffee lover, I’m also interested in the climate and the growing season elsewhere in the world. For example, in Indonesia, the rainy season puts a halt on the growing season, whereas in Columbia, they are able to grow and harvest coffee year-round as they don’t have a rainy season. Constant espresso – yey!

Of course, this definition of ‘growing season’ applies to most horticultural and agricultural situations, not just home gardens, allotments and communal gardens.

Where crops are grown under glass, whether in your greenhouse or in large commercial polytunnels, the garden growing season is extended rather than given a new definition.

greenhouse, border collie

Where edible crops and flowers for florists are grown in artificial, or rather totally managed conditions, for example, by using hydroponics, the growing season in relation to the weather outside is far less relevant.

But let us return to our beloved British climate, the topic of conversation in offices and pubs as well as on the allotment and in the garden centre!

The Met Office use the Central England Temperature Series to monitor changes in the British climate. The starting date for records varies, but many go back as far as the eighteenth century. The data is collected on a monthly basis and the year is divided equally into four seasons, which is why June is the first month of summer yet also has Midsummer – the Summer Solstice within it. The area used to collect the temperature and other weather data is an approximate triangle from the South Midlands to Lancashire and has both urban and rural weather stations.

So, when the Met office announced in March 2016 that six of the ten longest growing seasons have occurred within the last thirty years, they knew what they were talking about.

Using the temperature records from 1861 – 1890, the average growing season was 244 days. From 1961 -1990, the garden growing season had increased by about a week.

orange zinnia with osteospernum, annual flowers, tender perennials

By comparison, the most recent ten years of data, 2006 and 2015, show that the average growing season has been 280 days. This is 29 days longer than the period between 1961 – 1990, and 36 days longer than 1861 – 1890!

The increase in the growing season means that as gardeners we have a longer time in which to grow annual food crops and flowers. Fewer frost days, which is another current long term trend, also means that our ability to grow more tender plants is also greater. This could be we’re more successful in growing tender annuals sweetcorn and chick peas in the vegetable garden, for example. Ornamental half hardy annuals like cosmos could potentially flower for more weeks.

However, these changes are not turning our temperate, damp, maritime British climate into a warm Mediterranean one. We are likely to have not only more frost free days, but also more rain, especially over the winter months. This trend of wild, wet, windy weather has been a feature of recent years, as some gardeners, homeowners and businesses know to their cost.

cactus and agapanthus, South African gardens in Britain – Kew at the British Museum

Milder weather over winter enables many garden pests to stay alive when we would expect cold weather to kill them off. Plant diseases are an increasing problem, partly for the same reason. Garden pests and diseases that creep in with imported plants have become more of a problem as a result of these British climate changes.

But all is not doom and gloom. Gardeners have always had to amend their way of gardening to suit local conditions. For example, it must be obvious to those of you who live in North East Scotland that the average temperature in the English Midlands is not going to reflect your own gardening experience. Even in Cornwall, the climate varies between the milder southern coast and the northern coast.


Managing the Changes to Your Garden Growing Season

There are many, some easier to put into practice than others, so I will give them a blog to themselves in a couple of weeks’ time. Here are 7 changes to your gardening practice that you may find helpful:-

  • Know Your Garden’s Microclimate
  • Improve your Soil
  • Use Raised Beds and Borders
  • Use a Greenhouse, polytunnel or cold frame to protect from frost and excess rain
  • Adopt a Successional sowing method for annual crops
  • Make a weekly Health Check to spot diseases early
  • Use barriers to reduce Pest Damage

edible garden design bromley, raised beds,grow your own vegetables, gardening lessons,

If you have queries before the more detailed blog on managing your garden and benefitting from the longer garden growing season, you could:-

And if the sun is shining rather than the rain falling, why not have a relaxing cup of tea sitting in and enjoying the sight, sound and scent of your garden?


Related Gardening blogs you may enjoy

Soil – the plant food in your garden
So What Might a Plews Gardening Lesson Be Like?
Garden Planning – Your New Year’s Resolution for Your Garden
Grow your own vegetables in rows


garden arch with seats, arbour, pergola, climbing scented jasmine

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garden designer, gardening writer, gardening teacher, garden advisor

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