Ash buds

A series following the 72 British mini-seasons of Nature’s Calendar by Kiera Chapman, Lulah Ellender, Rowan Jaines and Rebecca Warren.

Dear Readers, the fattening of buds is one of the first signs  that spring is on the way – one day there are those little fat protuberances on the twigs, and then you blink and the whole tree or shrub is covered in a green mist. I always wonder how the leaves fit themselves into those tiny packages but this is apparently the wrong way to look at the situation: the buds have developed to fit the leaves, not the other way round.

Horse chestnut leaves emerging…

I have my own favourite buds. I love ash buds, mainly because they look like the hooves of miniature deer. Horse chestnut buds are sticky, and the substance that they secrete is thought to protect them from frost.

Horse chestnut bud

In her piece on buds in ‘Nature’s Calendar’, Lulah Ellender describes how some plants have ‘spiral phyllotaxy’. Phyllotaxy is the arrangement of the buds on a stem – in the horse chestnut, the buds are ‘terminal’ which means that there is just one bud at the end of the twig. ‘Spiral phyllotaxy’ is where the buds are arranged in a spiral around the stem – they are arranged according to the ‘golden ratio’, which means that each is separated at an angle of 137.5 degrees. This means that as each leaf unfurls, it doesn’t block the sunlight from its nearest neighbour. The conjunction of geometry and nature is a truly wonderful thing! My flowering currant doesn’t have full ‘spiral phyllotaxy’ but the buds are ‘alternate’, again so that they maximise the amount of light that each leaf receives.

My beloved Flowering Currant

Flowers and leaves emerging on the flowering currant

The  timing of bud burst is critical: if the leaves emerge early, they’ll have more time to develop and photosynthesise, but they can get caught out if there’s a late frost. The timing depends on a host of factors, including the genetics of the particular species, temperature, day length and position. Many trees need a period of cold weather during their  winter dormancy – by some mechanism not yet completely understood, this can enhance foliation and seed production. But as we know, the climate is warming, and in a study based on Henry David Thoreau’s account of  his time at Walden Pond in Massachusetts 160 years ago, plants are coming into leaf eighteen days early. This can have complicated effects on the rest of the ecosystem – caterpillars may not be available for nestlings at the right time for example. There is a delicate balance that can be adjusted over time, but the climate is changing very quickly. So let’s take a little bit of time to admire the small miracle that a bud represents.

Buds on the whitebeam

Oh, and sorry, but I couldn’t resist. I feel the need to post this poem by curmudgeonly Philip Larkin every spring, because it reminds me of hope, and my Mum, and spring, and those are three good things.

The Trees (1974)

PHILIP LARKIN

The trees are coming into leaf
Like something almost being said;
The recent buds relax and spread,
Their greenness is a kind of grief.

Is it that they are born again
And we grow old? No, they die too.
Their yearly trick of looking new
Is written down in rings of grain.

Yet still the unresting castles thresh
In fullgrown thickness every May.
Last year is dead, they seem to say,
Begin afresh, afresh, afresh.