As we adapt and grow in the face of climate change, we need to adapt the way in which we garden, such as planting more flowers for pollinators or planting species that will survive warmer summers and wetter winters. How often, though, have we thought about where these species come from, and what impact they may have when introduced to our gardens?
Maybe you have thought about it and have adapted and planted accordingly. You might even be aware that according to the Natural History Museum, the UK, as a whole, now has more non-native plants growing in our gardens, fields, and forests than native plants. This is said, in part, to have been caused by our long history of knowingly and unknowingly introducing non-native plants to the UK. But what does this actually mean and is it something to be concerned about?
Native Plant Species
There are a total of 1,692 recorded native plant species found throughout the UK and it is not uncommon knowledge that a majority of these plants are struggling greatly. The impacts of climate change are causing us to experience changes in weather, bringing in drier, warmer summers alongside wetter, colder winters. This, unfortunately for our native plants, particularly those in alpine and wetland habitats, means harsher unfamiliar conditions, causing many of our species to decline in numbers. Last summer, University of Stirling researchers said climate change had pushed Scotland’s rare arctic-alpine plants to the brink of extinction.
Non-Native Plant Species
Alongside our native plants, however, are the 1,753 recorded non-native plants now found in the UK. These, in the wake of our serious conversations around climate change, have become the favourite recommendations for gardeners to plant, as many hail from warmer and more arid climates that we are starting to see mirrored in our summers.
Some of these recommended plants include Cosmos, which originally hail from Mexico, salvias from the Mediterranean and Americas, or even asters from North America. Now there is nothing wrong with these recommendations, but we may be unwittingly prioritising plants which would not flourish in our normal wet autumns and winters, never mind the colder extremes we are starting to experience. Our native plants are more used to our cycle of seasons and are therefore more likely to survive these fluctuating conditions.
It is also important when we decide to plant non-native plants that we consider the effects they may have on our local flora and fauna. There is always the risk that we may unleash something larger into our gardens and beyond, or even alter the way our local natural environment operates.
This can be seen in such instances as the invasive Rhododendron ponticum that grows in such a way that it blocks out sunlight from forest floors, creating ecological dead zones. It is also a common host of phytophthora ramorum and p.kernoviae, both fungal-like plant pathogens which severally damage British trees.
Pollinator Problems
As an example of influencing how our natural environment works, we can look at the bases of non-native tubular flowers, where sometimes little holes have appeared. It has been found that some species of bees do not have tongues long enough to reach the nectar inside some of these flowers, such as certain salvias, so instead, the bees have been forced to adapt by learning to chew a hole into the flower base. The nectar is obtained but unfortunately pollination is bypassed.
Most native British flowers tend to have open inflorescence with smaller and wider tubular shapes that allow our bees to easily access the nectar. So, with our habit of bringing non-native, unfamiliar plants into our local ecosystems, we may be unfairly, albeit unknowingly, forcing adaptation, however small, on our natural ecosystems.
While this does show us that our ecosystems can and will adapt to new and unfamiliar horizons, not every species will adapt. We can use our awareness of how our native ecosystems work to support and protect its future against the effects of climate change.
Encourage Diversity
Ultimately, our garden’s diversity is key. Make room in your garden space for habitat pots that include small ecosystems of alpines, wetlands, and mini meadows.
You have a choice. When considering your garden planting this year, think about the broader impact you can achieve by buying native and locally grown plants. Every small action has the potential to create a larger reaction within our environment.
Georgina Sillars is a Geography, Society, and Environment graduate from Heriott-Watt University. She is passionate about the communication of environmental awareness especially within horticulture. Georgina is based in Ayrshire and looking forward to developing her writing and future career.