Our plants are behaving unusually this year, partly perhaps because of the weather extremes of climate change.  I’ve had pear blossom, species roses repeat flowering, tiny blueberries after the plants had a near death experience in spring.

I even know of someone whose runner beans are dying as a result of high temperatures, not very low ones. The list goes on and you’ll have seen other odd behaviour in your garden.

Many of my trees are shedding leaves prematurely. Before writing this in mid-September I had a walk through my woody areas and was struck by the build-up on paths.

Day length determines when trees drop leaves in temperate regions as well as their own internal timetables. This can vary hugely: ash, birch and sallow are much earlier than oak and alder. 

And two trees of the same species can behave quite differently depending on age, location and general growing conditions. A young oak in one part of my ground has all its leaves, while another mature one elsewhere is shedding now, which is ridiculously early.

Disease plays an important part in all this and explains part of my leaf drop. Ash are succumbing to ash-die back; Hymenoscyphus fraxineus and some alders have been infected with Phytophora alnii so these diseased tree inevitably shed early.

As we all know, diseases new to Scotland may also be a result of climate change. Insect damage, stress as a result of poor growing conditions and leaf scorch – browning of leaf edges – especially in urban areas with poor air quality are some of the other reasons for damaged and falling leaves.  

In his 2022 book, Trees, Emeritus Prof Peter A Thomas of Keele University suggests another reason which is supported by some scientific papers. The reason is linked to photosynthesis. As trees grow, part of their strategy is to rely on leaves for energy collected through photosynthesis.

Warm, sunny spells which are happening even in Scotland, let trees photosynthesise more efficiently. Thomas suggests that once trees have absorbed enough resources to see them through the winter, they no longer need leaves. They extract nutrients from leaves in the usual way and discard them earlier than before. We might find ourselves collecting leaves for leaf-mould earlier than usual this year.

Our memories are never as good as we’d like, at least mine isn’t. So with all these changes happening in and around our gardens, why not take a note of them? I’ll make a start and wish I had done so years ago. The Woodland Trust has started collecting and collating a record from all over the UK, called Nature’s Calendar.  For more information, visit: naturescalendar.woodlandtrust.org.uk

Plant of the week

Hylotelephium spectabile ‘Brilliant’ is an autumn flowering stone-crop bearing large, flat heads of bright pink flowers. While rain and fluctuating temperatures can dull the colours of many flowers, ‘Brilliant’ keeps its vibrancy and when the flowers eventually fade and go brown they can give a little height and structure to a flat winter border. Leave them for as long as you find them attractive. The plant needs well drained soil and a position that is still sunny in late autumn.