IN this week of love (unless you're embroiled in a tender exchange over speeding points), let us turn to the bearer of arms that are always outstretched to embrace, no matter what our transgressions.

Let us turn to trees.

There is reason to say this. Over the years, people have used trees as giant, living Valentine's cards, declaring their love by carving their initials into the bark, a practice that gave rise centuries ago to the Roman proverb Crescunt illae; crescant amores – as these letters grow, so may our love.

Trees reach for the light all their lives and every now and then catch our hearts in the process. Sadly, not just our hearts. They also catch plastic bags, party balloons, kites, the odd can, the whole blown and tossed and thrown melee of urban flotsam and jetsam. Sorry, you thought this was going to be a romantic piece. No, it's essentially about litter.

In the early 1990s, an American magazine ran two pieces, imaginatively titled Bags in Trees and Bags in Trees II. The author listed all the items he'd seen in trees in his native Brooklyn. The list included shoes, dolls, a white jujitsu sash, the odd hubcap and endless plastic bags.

It's the bags that hold sway here too – or sway and hold on. They're everywhere – and some of these trees haven't even paid for the M&S ones. There should be an adjective to capture the urgent sound that a trapped supermarket bag makes – susurrplasitcation perhaps, or sussurpolyration. Helium balloons are popular catches too, although sadly, there are no examples of the rustling becoming absurdly high pitched as the gas leaks into the branches. Shame – that would freak the crows out.

My personal favourite was a patchwork blanket that was tied by its corners to the branches of a plane tree that I passed every day when I commuted into the city years ago. It would seem to disappear in the summer – hidden by the leaves – only to reappear in the winter.

This poor, homeless fabric withstood snow, rain and gales – and then one morning was simply gone. Fortunately, it lives on a in a box in my loft in a series of pictures that show the tree changing around it. Needless to say, as excuses for being late for work goes, "taking pictures of a blanket in a tree" never sounded too convincing.