Published 5:30 am Saturday, November 8, 2025

By Leslie Cox

You just have to know a title in my Inbox starting with “Lab Report” was going to catch the eye of this retired techie. Especially when they added “climate change” and “garden” to their tag. Then they really hooked me by mentioning “research studies”.

I know many of you are more likely to read your gardening magazines and scrutinize the newest seed and bulb catalogues rather than struggle through a scientific document full of strange, unpronounceable words. Cannot blame you as it is way more fun to see what is new on the horizon for the garden than reading a stuffy document that probably would not make much sense to most gardeners.

However, not all lab reports are ‘stuffy’. Some, such as the one in my Inbox, were written in perfect layman terms which everyone who read the document would be able to understand. And it was very informative on three different subject matters from the basis of climate change effect.

The first to catch my eye was the one on bumblebees. These pollinating insects have always been amongst the first to appear in our garden in early spring to catch the first blossoms of the season. Their fat fuzzy bodies are well suited to handle cool temperatures and they even seem to weather the odd rogue overnight freeze with finesse.

But enter climate change with its ever-increasing temperatures and the bumblebees begin to suffer. I will not bore you here with the intimate details of the scientists’ research studies in Switzerland over a 13 year stretch. I will just spill the results.

They found queens who were exposed to wet years when they were immature larvae generally suffered from a lower body mass, increased risk of infection, lower reproduction and a higher rate of mortality as mature queens. The scientists reasoned this was likely due to poor foraging material for the workers who were feeding the developing queens. Add in wet conditions that are prime for parasite development and you have the perfect double-edged sword that will decimate bumblebee queen populations.

The next study was on “plant phenological shifts”. For those who do not know what “phenology” means, I cannot say it any better than to quote from my Taylor’s Encyclopedia of Gardening. It says: “phenology – an absorbingly interesting science having to do with the relation of climate to the periodic response to it, and, in the garden, best manifested in the time of flowering and fruiting”.

Most of this particular study was based on the meticulous records of a horticultural professor who regularly visited three university gardens over a 58-year period. He selected 607 plants and recorded the dates when each of the plants broke bud, when their first flower appeared and when their colour changed in the fall. Of special note, the 58 years covered many La Niña and El Niño weather cycles, including when they had a stronger or weaker impact on the local weather.

Comparing the professor’s records with weather data from a climate station in the area, they found 87 per cent of the 607 plants leafed out 2.6 days earlier in each successive decade, 80 per cent flowered 2.5 days earlier and 84 per cent displayed fall colour 10.6 days earlier.

The final study had to do with environmental impact. The question: does extreme heat cause higher release and leaching of fertilizer nutrients? During this study, they experienced a heat dome event over 6 days with temps as high as 45 degrees C…at least 12 degrees above average.

The test results on the leachate after this heat event showed the level of Controlled Release Fertilizer were at a detrimental levels for the surrounding waterways.

I think we need to really start paying more attention to climate change. Especially in our gardens.