Deborah Moggach: I have that rare thing in London, a large front garden. This means that I do a lot of weeding in public. Sometimes people who have been visiting the nearby psychiatric unit wander in and give me advice. One man told me he was Francis Bacon's son and could easily afford my house if I wanted to sell it. I didn't like to tell him that, as far as I knew, Francis Bacon wasn't that sort of chap. On another occasion, I was sunbathing when a man delivering an Amazon parcel walked down the path, stood above me and said, "Roll over and show me your tits." Yet another reason, on top of all the others, to boycott that hideous organisation.

I mention these episodes because, to me, gardening is a solitary activity and I prefer talking to nobody at all. I hesitate to say spiritual, but in fact I do drift into a heightened state of joy when alone with the plants I know so well. I have a tender regard for the most fragile – heleniums, for instance, which I try to grow every year and which immediately get slaughtered by the slugs. Off I go to the garden centre to buy yet another pot for £7.99, hope rising in my heart, only to be dashed yet again. As the late, great Alan Coren said, a gardener's handiest tool is their wallet.

I also love the sturdy, reliable plants that sprout up year after year, often when one has forgotten they exist. Dicentra, because it flowers so early; rudbeckia, because it flowers so late. I'm even quite fond of my so-called weeds. My garden has a lot of ground elder, which is meant to be a curse, but I find it satisfying to pull its roots out as far as possible before they snap. Herb robert is a particular favourite: delicate, beautiful and flowering all summer.

I try to keep a balance between wild and tamed: an only-just-controlled, cottage garden-like disorder. In fact, most of my happiest combinations are accidental. Poppies, feverfew and my favourite plant of all, foxgloves, spring up in the most unprepossessing of places and find themselves mingling with forget-me-nots, another self-sower, or those deep purple geraniums that grow out of the most sterile cracks.

The plants I love best are those that are lovely all through their life-cycle. Tulips are the best, beautiful from their glaucous green shoots to their graceful deaths, when the petals are shed like skirts and the striking stamens remain.

Estate agents go on about easily maintained gardens – they actually consider this a selling point. I feel quite the opposite. It's a labour-intensive garden for me. Otherwise, what would you do in it? Sit around, gazing at it? No real gardener does that. Sit us down with a glass of wine and we're up in a trice, just pulling out this bit of bindweed.

I don't think gardening helps my creativity. It's soothing and joyful, but my mind is a blank. No stories have suddenly sprung up as I'm heaving sacks of manure. What it does do is give my imagination a rest. Characters can settle down in my head, like house guests settling into their beds. I can relax.

I've always wanted the writer's epigraph on my grave: A Plot At Last. But now I think of it, one could take this inscription in a few ways. Heartbreak Hotel, by Deborah Moggach (Vintage), is out now.

Patrick Gale

Gardening is a deep, compulsive pleasure, inextricably associated with my love for my mother and sister, both avid gardeners whose ideas I continue to pilfer. I could happily neglect a novel to spend an entire week weeding. I savour bulb catalogues as some men do dirty pictures, am quicker to recall botanical Latin than people's names and get dribbly over a crumbly compost or the intense true blue of an anchusa. Like baking, dog-walking or ironing, it's an oddly productive displacement activity for a writer: occupying the body in simple tasks sets the mind free to tease out a stalled plot or an unclear motive.

If dated from the first cuttings I brought along, this garden, inherited from my husband Aidan's parents at their farm near Land's End, is 16 years old. The original garden was so hemmed in by a concrete wall that most of its flowerbeds lay in deep shade. We did what we could within it, but then we burst out.

We did this first, out of sight of the house, on its sunny, seaward side. At first it was glaringly hot, a home for wind-hardy, southern-hemisphere exotica, but then the vital windbreak of olearia, pine and elaeagnus grew to the point of casting shade as well as giving shelter. Now it's an eccentric, twisty garden of more temperate plants.

With the building of the shed, my first dedicated writing space, I stole a little of the farmyard, creating a high-walled kitchen garden and a lower-walled area just outside the shed door, which we planted on three sides with roses and nepeta. Perhaps it was the difficulty of choosing favourites for this that absorbed so much of 2013 – my new novel is a year late.

Trevilley is now fronted by the country's first and last walled rose garden. The beds are all raised – Land's End soil is barely a foot deep – so I'm hoping, when I inevitably inherit the arthritis that dogged both my parents, I'll still be able to weed and deadhead. I think we have 165 roses. If I say that fast enough, the cost doesn't make me feel so guilty. Patrick Gale's delayed novel, A Place Called Winter (Tinder Press), will be published in March.

Penelope Lively

I am a much diminished gardener. Time was, I gardened on a large scale: grass, yew hedges, shrub roses, orchard, two rushing streams, vegetable-growing on an industrial scale. Now, I have a small paved London back garden, which is just as well, because I can't do much in it apart from watering and deadheading. Never mind – my Bulgarian helper, Danni, does everything I can't and last autumn we completely made over the long raised bed on the sunny side of the garden, installing 12 David Austin ground-cover roses and two climbers, she planting and me interfering. They will foil the local foxes, who had taken to lounging on the euphorbia that was there before.

It is a pot-heavy garden, deliberately. That means you can move things around, throw out anything not earning its keep, and indulge in something new and irresistible at the garden centre. The pots are everywhere – large ones with different kinds of pieris or fuchsia, smaller ones with heuchera, and grasses of one kind and another (the hakonechloa always has square ends because cats have chewed it), and recent acquisitions: a lovely purple-flowering mint, prostanthera, a blue corydalis and astelia, with its silvery-red, swordlike leaves.

In the middle is a corokia, that New Zealand shrub with tiny, silvery leaves and little yellow flowers in spring. My daughter Josephine gave me this one 20 years ago; it must be terminally pot-bound by now, but seems entirely happy, sparkling silver when the sun catches it, and the perfect centrepiece because it gives height but is see-through.

The raised bed on the shady side is occupied by ivy and an ancient fatsia. I respect this for its tenacity, and like its structural leaves, but it has to be controlled. My neighbour is a keen gardener and I benefit from his climbing roses; we enjoy garden chat through his Rosa 'New Dawn'.

The steps up from the kitchen door are in deep shade, so make a good fernery – one pot per step. Once at the top, you are into the sun, and there's a big tub that has traditionally been used for seasonal planting, bulbs for spring, geraniums for summer. But I have got bored with that and splurged on a gorgeous acer, which will give height against the wall, and can have pansies or species tulips at its foot to ring the changes.

Blue campanula romps over the entire garden, self-seeded in cracks in the paving, swarming up the brick walls of the raised beds. Fine – let it. After flowering, we tidy it up, and when the paving is pressure-hosed in autumn, you think the campanula has been battered out of existence; no way – it simply jumps up again in the spring. And there are great clumps of Erigeron karvinskianus, the pink-and-white Mexican daisy so favoured by Gertrude Jekyll.

I occasionally think nostalgically of my previous garden – harvesting the potatoes, the first pick of broad beans – but actually this more fanciful little town patch does me nicely as my last garden. Ammonites And Leaping Fish: A Life In Time, by Penelope Lively (Fig Tree), is out now in paperback.