Notes from the Garden Shed: January 2016

Where do plants go in the winter?

Yes I know they don’t fly south or go to the coast in flocks but there is a change in their behaviour, plants drop their leaves, writes Garden's Manager Paul Richens. You could say that they ‘withdraw’ underground. Charles Darwin, famous for his ‘Origin of Species’ is less well known for turning his scientific focus in the second half of his life, towards the study of plants. He wrote several books on the subject, one of which, The Power of Movement of Plants, introduced a new understanding of plants. In the last paragraph he says ‘We believe that there is no structure in plants more wonderful, as far as its functions are concerned, than the tip of the radicle’  [Note: The radicle is the embryonic root system of plants].  This became the ‘root-brain’ hypothesis of Charles and his son Francis Darwin sadly much derided in his lifetime but as with many things ‘Darwin’ he’s been proved right since.

Onion roots shown growing down to 3 foot or 91cm (from: Roots Demystified by Robert Kourik) 

Onion roots shown growing down to 3 foot or 91cm (from: Roots Demystified by Robert Kourik) 

What I would say is that a TV aerial on the roof of a house does not hint at all the activities below - so with plants, their structures above ground (what we call trees, shrubs or just plants!) just don’t give us any idea of the movement and industry below ground.  So we see deciduous plants (those that drop their leaves in autumn) withdrawn underground with just their root systems active.  This is useful to us gardeners in allowing us to prune on ostensibly non-functioning wood reducing the shock to an otherwise living branch. So we’re in full ‘winter pruning mode’ at the moment. On a count, we now have around 20 sleeping trees and shrubs to tend in the Skip garden.

Finally, you might wonder how plants take their cue to withdraw in autumn then which of nature's clues they use to wake-up again in Spring and even if this unseasonably warm weather has any effect on them. Certainly apple trees need at least 50 days of downtime otherwise they wake up grumpy and don’t perform so well (my mother is vindicated!).  It looks like some plants have been fooled by the higher than normal temperatures but most will be ‘watching’ the day length before they venture above ground.

Happy secateurs sharpening for your winter pruning and early snowdrop/daffodil spotting!