He did not, however, hold a long, strong finger down on his emotional life.

As I got lunch under way, he wandered into the kitchen and took up a post by the window. I fluffed up the parboiled potatoes in the colander. ‘Why do you do that?’ he asked.

I spooned them into a tray of hot fat. ‘Makes them crisper.’

‘I must tell Alice. We’re both learning to cook.’

I pushed the tray into the oven. Sam should have known by now that Alice was not the sort of woman to appreciate cookery tips. What was more, her immaculate good looks and naked ambition made older women uncomfortable. ‘How is she?’ I avoided his eye.

‘Fine.’ A pause. ‘I think.’

‘You think?’

‘She went skiing in Austria.’ Sam dug his hands into his pockets, which made him look just like his father. ‘An all-party girl’

Alice hurt Sam regularly. He was admirably reticent about it but Nathan and I did not require chapter and verse. One fine day, he had met the golden-haired Alice at a conference and, far too quickly for warnings, had fallen in love. There was nothing to be done, except sit it out.

To go with the chicken, I had planned tarragon gravy and tiny carrots, peas and broad beans. The carrots were fiddly and I had to concentrate on scraping them. ‘Lay off, Mother,’ Poppy would say – but there was no point in having children and not involving yourself in their lives. It was as natural as breathing.

‘I asked her to marry me, you know’

The peeler caught my nail and I sucked my finger. Alice’s answer was reflected in Sam’s stiff attitude. I knew I should be the Samaritan, the wise counsellor, but Sam’s hurt and disappointment distressed me so much that I was at a loss. ‘Sam, why don’t you open a bottle of wine?’

‘It’s OK. I can talk about it.’

‘So…?’

‘She doesn’t feel there’s any point in getting married. She has a fantastic job and a fantastic salary. A fantastic flat. A fantastic car. The works. Why spoil a good thing?’ His eyes were dark with longing. ‘But I want to start something.’

‘Have you explained this to her?’

He shrugged. ‘Sure. Alice feels that people do unspeakable things to each other when they get married. She thinks it’s wrong to base your life on the idea of love. Women don’t buy that any more. As an organizational principle, love has flaws.’

‘Will you give up?’

‘I don’t know’

‘Oh, Sam…’ I took his hand and stroked it, willing his hurt on to me – which is what mothers do.

When the chicken was ready Nathan carved a couple of pieces of breast and arranged them in a fan on Mr Sears’ plate. I added the roast potatoes and vegetables, and a separately made portion of gravy: Mr Sears had an aversion to herbs. ‘I’ll only be a couple of minutes,’ I said, and left Nathan stirring the gravy and Sam laying the table.

Mr Sears lived on his own next door and was bedridden. I went down the stone steps to the basement of number nine. During the war, Lakey Street had been the random target of a bomb flung out of a plane on its way home to Germany, which had destroyed three houses. During the fifties, the council had nipped in and built three neither beautiful nor appalling replacements.

‘Who’s that?’ Mr Sears called at my knock.

‘Rose.’ I was never the person he wanted, which was Betty, his daughter who, long ago, had packed her bags and done a bunk. Betty got in touch with her father once a year, and then only grudgingly.

I let myself into his sitting room where he had been eased into his chair, surrounded by newspapers and full ashtrays. ‘I’ve brought your Sunday lunch.’

It was important to remind Mr Sears of what day it was because it was difficult for him to remember. Time no longer functioned for him in the conventional manner and calendars were of no use to him: he never looked at them. ‘That’s nice,’ he said, looking surprised. ‘What made you do that?’ Off and on, I had been bringing him Sunday lunch for the last five years.

I fetched a tray from the kitchenette, and settled it on his knees. ‘Chicken. Your favourite. Unless you’ve changed your mind.’

He poked at a carrot and I knew he would need encouraging.

‘Thought you might like to know, Mr Sears, they’re taking off the Routemasters on the eighty-eight and putting in pay-the-driver buses.’

‘Are they now?’

‘Everybody’s grumbling about it. There’s a protest meeting being organized.’

This information excited Mr Sears so much that he took his first mouthful and I relaxed.

Ours was a carefully developed friendship, which had taken years to mature. Before he had become housebound, Mr Sears had spent his days riding the buses. They were his passion and he had mastered the network of interconnecting routes, a king of the city. What he did not know about timetables, tickets and bus territory nobody knew. So, in a small way, I had made buses my business too. I told him about breakdowns, the latest adverts I had seen pasted on to their sides, and sometimes swung by the depot in Stockwell to give him an update.

Mr Sears’ other great passion was Parsley, who treated number nine as her second home. If the subject of buses ran out, we talked about her and Ginger, the cat Mr Sears had once had.

I checked up on the rota to see which of his Homecare nurses would put him to bed. ‘Marilyn’s coming this evening, Mr Sears. She’s the one you like.’ I heard that falsely cheerful note creep into my voice. It made me wince.

Mr Sears shot me a look.

‘I hope you enjoy your lunch,’ I said.

‘Chicken gives me a headache,’ he said, to punish me.

Immediately after we had eaten, Sam left Lakey Street, and I insisted that Nathan and I took our coffee out into the garden. ‘See?’ I said, flinging open the french windows. ‘Perfect’

The first growth of the Buff Beauty was struggling for space through the bullying Solanum jasminoides. The Marie Boisselot clematis had already put out a few leaf buds and the Rambling Rector rose was readying itself to dust, later, in the spring, its tiny creamy buds – like Poppy’s baby fist along the fence. In fact, all the plants were poised to shake out their plumage for their annual show. Lavendula ‘Nana alba’, Artemisia nutans ‘Silver Queen’ – my lovely, tender children. I almost forgot the olive tree in the stone pot. That, too, had a silvery gleam in the thin light.

During the winter, moss had edged over the stones and colonized the bench. They required dousing and scrubbing with disinfectant and I fetched a bucket. Nathan scuffed the patio with his shoe, revealing grubby streaks of the stone underneath.

‘You’ve been very quiet, Nathan.’ I scrubbed at the bench and wiped it over with a cloth. He watched me.

‘It’s far too cold.’ He sat down but did not look at me and I wondered if he was angry with me.

I tried again. ‘I think I saved the clematis.’

‘I don’t know why you’re obsessed with white. Can’t we ever have a bit of colour to liven things up?’

It had crossed my mind more than once that Nathan was jealous of the garden. ‘I don’t know. I love white – but maybe as a change I could go for red.’

Now Nathan said something that struck me as strange. ‘I don’t think I’ve ever understood you, Rosie.’

It was too serious a statement not to treat it as a joke. ‘You don’t have to.’ I leant over and kissed him. ‘That’s part of my mystery’

‘Don’t be silly.’

Why did I love white in a garden? No doubt some of the books that passed over my desk offered explanations of the white period in a gardener’s history. Picasso had had a blue one, and plenty of print had been devoted to analysing it. Perhaps white gardens revealed an unconscious yearning for purity. More likely, the fat, innocent buds butting their way through chocolate earth, the tender, reliable goodness of a garden, provided a direct contrast to what took place in the world. Yet any fool can tell you that it is not the answers which are significant, but the garden itself. My white beauties traced pathways over rotting fences and spread their cool canopies over tired city soil. It may be true that I was gripped by the longing for clarity and resolution that white suggests, which I could not explain to Nathan, but it was the visible beauty that was the real point.

Nathan stood up. ‘I’m going indoors.’

‘Would you like to go for a walk? I can do this another time.’

‘No. I know you want to tackle the moss. I might take myself off for a stroll.’

‘Fine.’

I refilled the bucket at the outside tap, poured in disinfectant then got down on my hands and knees and began to scrub. The disinfectant was astringent and clean-smelling and made my skin tingle. Nathan moved about inside the house. He washed something up, made a phone call, and then I heard the bang of the front door.

The scrubbing brush was new and bit hard into the moss. A swathe of freshly minted stone flag appeared. A cheap substitute for limestone, this stone had been imported from India, hewed from hot, dusty plains. It was old and some of the flags had fossils imprinted on them. A foamy leaf. A fishbone of fern.

I traced the fern with a wet finger. Nature produces her enormous variety from only ten basic patterns: the whorl, the spiral, the crystal, the branch, etc. I learnt that while I was a student at Oxford. I loved that piece of information. I found Nature’s strictness reassuring – and I was the woman who still cherished a silver medal engraved ‘Rose Uttley: for Tidiness and Not Being Late. Form 3’. I liked the notion of such order, such simplicity. It was one of the reasons I had married Nathan.

Etc., etc.

I finished the patio and embarked on the garden furniture. It was hard work and I grew pleasantly warm. Every so often I looked up – just for the pleasure of looking – at the green and brown of the waiting garden. When we had moved in, forty-five feet of bleak, leached London clay, tangled with briars and rubbish – the same imaginative estate agent had called it ‘a mature prospect’ – had greeted me. ‘Try me,’ I fancied it was saying. ‘I dare you.’