Alys Fowler: rot

‘Too many of us tidy away what we see as death in the garden.’ Photograph: Alamy

There is a policy of live and let die in my local park. Some trees are pruned and felled as necessary, but many are allowed to stand until the cycle of nature disposes of them. I watch these giants wobble and tip: sometimes they topple in one, bringing down small trees with them and taking over paths. Others seem to dissolve, as a once-strong trunk melts into a confetti of soft wood.

They are breathtakingly beautiful, and the detail in the decay is quite something. The patterns the insects leave, the fungi and mould, the woodpecker’s marks; there is as much life this side as there was in the living tree. If it’s soft rot, you can sink your hand into the tree; the “punk wood” in the middle is like a sponge, resisting, yet tearing. It is such a visceral experience that I trample through the mud, day after day, to see and smell, to touch and wonder at it all.

The process of decay is complex and chiefly happens through lignicolous fungi. Tiny strands of fungi take a once-mighty tree and return it to its most basic materials. All forms of life take advantage of this process, building homes and dining off the instability.

I fear too many of us tidy away what we see as death in the garden. We saw, bag up, skip or burn a process that is as beautiful as any bloom, as enriching as any compost. Large rotting trees can be dangerous, so it’s wise to talk to a tree surgeon if a seemingly healthy tree starts sprouting mushrooms or shows a crack. The loss of a tree is often dramatic: it’s understandable to want new light and new vistas. But at other times, leaving a tree to its natural cycle can be just as enlightening.

If you can’t leave it in place, plant a portion of the trunk elsewhere. Upright dead trees are important habitats and food sources for wildlife such as bats, woodpeckers and nesting solitary bees. Alternatively, use the chopped timber: a wall of stacked logs can make a raised bed. Eventually this rots, but in the meantime it is host to a thousand insects and home to many more. If there is not enough wood to create a small wall, edging beds with chopped logs works well, particularly with woodland-type plants. The graceful curves that limbs and branches create make perfect organic boundaries.

And if you burn it, as long as there’s no coal involved, the ash is rich in potash, and this much at least can be returned to the soil. Spread it around bushes and trees to boost the next round of flowers and fruit.