Anna Pavord: What happens when a tree comes to the end of its life?

Our gardening correspondent had to call in the tree men to cut out the dead half of a willow

Pollarding, as seen in these willows, can keep a tree healthy for longer (Alamy)

The tree men have been in, cutting out the dead half of a willow. We generally leave this kind of work till the winter, but the willow worried me. Like most fast-growing trees, it is brittle. And this one is big. I threw a tape measure round the deeply fissured trunk – 240cm (8ft), it said. I thought it would be safer to get the dead branches off before the equinoctial gales started hurtling up our valley. There are always strong winds at this time of year and I had a ghastly picture of the willow shedding its load – each branch as big as a tree – over the footpath below.

Every tree man I've ever known is deeply pessimistic. They shake their heads slowly. Suck their teeth. Sigh. “The whole tree's on the way out,” said Pete. I said I suspected he was right, but thought we'd deal with the obviously dead bit first. We'd see what the rest looked like next season. More sighs. Reluctantly Pete put on his climbing gear. The tree hung like a gallows with ropes and bolts and shackles.

I won’t miss it. Already the view across the valley has opened up

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But you have to be patient through the preliminaries because the skill of tree men is worth any amount of waiting. The climbing is tricky enough, you might think. But after clearing the small branches, the climber has to cut and carefully lower each main branch in pieces. Wood on a tree always turns into twice as much wood on the ground. These guys had brought a huge chipper – noisy but amazingly effective. They ground up all the brash and small branches to make the mulch that we use on the paths on the bank. One way or another, we'll use every scrap of that tree.

The willow grows on the bank below the house and was here when we came. It's most probably the native Salix alba in the form called “vitellina”, which is Latin for egg-yolk yellow. That is the tree's only attribute. When the narrow grey-green leaves drop, the twigs shine out very brightly through winter in a rich gold-brown. It's popular with birds though, especially the ones with beaks sharp enough to dig out insects from the deep crevices of the bark.

So why did it die back? I suspect it is just because it has reached the end of its life span, reckoned to be about 50 years for a free-growing native willow. If you pollard the tree, you can extend its life considerably.

This is how I most like to see them: pollarded willows growing alongside a stream in a flat water-meadow. Grown like this, the trunks gradually become hollow, but the new sprouts at the top keep on coming. It is remarkable. But the trees need to be managed, with the biggest shoots cut out each year to reduce the weight and encourage fresh growth. The inside of the trunk gradually crumbles away, making the “willow dust” that was once recommended as an ingredient, along with the earth of molehills, in recipes for home-made compost.

If, as our gloomy tree man predicts, the rest of the tree dies back next year, could pollarding be an option? We would take off the remaining branches, leaving the trunk standing at about eight feet. But I doubt (even before Pete tells me so) that it would succeed. Pollarding works well on young, vigorous trees such as poplar and willow. But this is an old tree and I feel that death is in the trunk as well as the branches. And a pollard, on its own, stuck halfway up a bank, would not look (or feel) comfortable. I won't miss it. Already the view across the valley has opened up. And an ornamental pear tree (Pyrus calleryana “Chanticleer”) on that same bank is already 30ft tall. It was the first tree I planted here and it has grown much faster than I expected. But in shape it is narrowly conical. It won't block out the view the way the willow does.

There are willows I like, including some of the fancy ones such as Salix irrorata and S. melanostachys which bear big, furry catkins before the leaves emerge. Our native pussy willow is S. caprea and there's already one of those down in the valley.

I got hold of a bundle of hardwood cuttings of S. melanostachys which has sumptuous catkins that are almost black. From these I raised five trees, all of which were doing well until this year, when every single one was barked by squirrels. I asked Pete to cut down the sad, dead skeleton of one of these special willows. “Take it down to the ground,” I said. “I'm hoping it may shoot again from the base.”

He gave me one of his special you-must-be-joking looks. “You must be joking,” he said.