Give it the chop: There's no place for sentiment in an ordered garden. But a sprawling, eight-year-old magnolia tree is a test for Emma Townshend's resolve

A friend of mine has spent the past two weeks agonising over how to split up with her boyfriend. 'It's not if, it's when!' she howls to her friends in the pub, while he has no idea what trouble's about to hit. She says her heart sinks just looking at him; I know the feeling, because I look out into the wintery garden at the moment and have similar thoughts about the bloody magnolia tree.

My mum and I picked it out from a nursery for my birthday about eight years ago. I guess I knew even then that one day it was going to be too big for the garden. But received wisdom says magnolias are slow-growing. The problem being that I am also a slow-moving creature, and years and years go by, I don't move house, the magnolia tree keeps growing slowly and now it's got much too big.

Surely most kind-hearted gardeners must have something growing that they really don't want, but can't really bring themselves to be tough enough to get rid of. For the past three years, around March, I've tried to force myself to chop down the magnolia, preferably before it goes to all the trouble of flowering - the first, white hint of spring - and then of producing all those big, green, happy, unsuspecting leaves. But I just can't make the final decision to do it.

The responsibility hangs over me like a dark cloud. In recent years, I can't even enjoy that bit of the garden, because on a summer's day I'll end up looking up at the magnolia. All that effort it's gone to. Procrastination. Guilt. Not a good combination. So, I end up sitting out the front instead where there are no bad vibes - and no leaves blocking the sun either.

Clearly, the problem has something to do with that sentimental gift factor. But my main difficulty is just a weird sense of responsibility. The magnolia never asked to be planted in a tiny little - stupidly little if we're being honest - garden. But it's done its best. I planted it in a rubbish, thoughtless position, where it was never going to fit, shouldn't I just now suffer the tree, given that I put it there?

In my experience, you do feel a special gratitude towards the things which persist year after year in your garden. You start to think of your long-term survivors as loyal, trusty and part of your gang. I feel a deep affection for the echiums that now self-seed in my front garden every year, giving a flavour of sub-tropical Tresco, and requiring only a bit of newspaper and a black bin bag laid over them if it frosts. Somehow, I feel as if these persistent survivors must have a reciprocal affection for me. After all, they've made the effort to stay.

Under the circumstances, I have seriously wondered whether I might devise some sort of ceremony for cutting down one of my own platoon. I mean, people increasingly recognise that it is not totally out-there to have a funeral for a much-loved pet. What about for a tree that you'd love, if you had a bigger garden, but which just doesn't fit?

In Claire Nahmad's Garden Spells, she suggests a charm to say over an uprooted elder - 'Elder Mother, within the tree/ No disrespect I mean to thee.' I somehow don't imagine that the ghostly Chinese ancestor of my magnolia is going to take kindly to being referred to as an elderberry. On the other hand, aficionados of tidying-up literature will know, there is no one like Karen Kingston and Denise Linn to instruct you on how to chuck things away. So I spend a bit of time flicking through their feng shui-themed, clear-up-your-clutter tomes. Say goodbye properly, Kingston says. Take a photo. Then just get rid of it.

In the 16th century, they didn't have this problem. According to Keith Thomas - a fearsome, owlish Oxford don who wrote a much-consulted history of English attitudes to nature - infants were swaddled, children beaten and trees pollarded, because they needed to be. In those days, people believed that kids and trees got out of control if they weren't reined in.

It wasn't until the romantic 18th century that people began to take issue with the idea of restricting the natural growth of a tree. Attitudes swung strongly in favour of letting trees grow freely, giving British trees a very British liberty to make their own way in the world. And, as a literature-teaching friend of mine pointed out, you can tell the baddies in Jane Austen because they chop down trees - think of that nastiest of all sister-in-laws, Fanny Dashwood, in Sense and Sensibility, who has the ancient walnut grove felled to make a fashionable flower garden.

But if the magnolia is just too big, if it's shading other plants? Surely, I'm not such a baddie? Even if I did (sniff ) buy it with my mum. 'Sentimental tree planting is a total minefield,' says another friend. 'I planted three trees in our garden for my three children. Two of the trees survived, and one of them died. Imagine how I felt. It's a terrible, terrible feeling. I vowed never to do it again.' Pete, a forester and tree surgeon, is utterly pragmatic. 'Trees growing too close to each other will never flourish. Stop kidding yourself. You'll feel this huge sense of peace that comes from getting it over with.'

If I was really put on the spot, I guess more than anything I remember looking at a magnolia tree out of the window when I was little, and it completely symbolising spring. What I actually need to do is admit that I really want one, but I just don't live in a big enough place. Magnolias in towns are fabulous, but they block out all the light, all summer, and take up the whole garden.

Yet even after all that, I can't help thinking about the little white flowers growing inside the buds. Don't scream at me, but I may be about to give the magnolia one more year. s 'Garden Spells', by Claire Nahmad (Parkgate, £4.99). 'Man and the Natural World: Changing Attitudes in England, 1500-1800' (Penguin Press History, £14.99). For information on clearing clutter and the books of Karen Kingston and Denise Linn, go to www.cluttergone.co.uk

Q&A Emma answers your horticultural queries

Could you recommend a good, interesting book on the history of gardening; it doesn't necessarily have to be something with loads of pretty pictures.

Marion Hughenden, Bucks

There are lots of lovely garden history books available these days, so you have a really good choice. The delightfully chatty, and insidiously informative Little History of British Gardening, by Jenny Uglow (Chatto & Windus, £16.99), is a good introduction. I personally loved The English Garden: A Social History, by Charles Quest-Ritson (Penguin), which does also have some pretty pictures. And take advantage of the Shire Garden History series, which is made up of inexpensive (£5.99), detailed books by experts - I particularly enjoyed Mavis Batey's Regency Gardens and Hazel Conway's Public Parks.

Is it true there is now a chemical slug killer

approved for organic gardeners? Please say it's not a dream.

K Stern, via email

It's real. Advanced Slug Killer - composed of a metal compound and ferric phosphate - has been developed by Growing Success and has already been used for some time by organic farmers. If you are really keen, Google the US government's report on its environmental effects - type in 'EPA' and 'ferric phosphate'. This should answer any nagging doubts. All this, and it only costs £2.50 for 250g. I'd be very interested to hear from readers who can let me know how well it's worked for them.

If you do one thing...

restrain yourself

The temptation at this time of year is to buy loads of packets of seed that then never get sown. For 2007, make it your mission to avoid accumulating a drawerful of ungerminated vegetable delights.

Think about it before you buy. Limit your shopping to three packets of seed that you really want to grow. When you actually finish up all of the packets, reward yourself with more.