Avant gardens: Anna Pavord gets her head (almost) around conceptual gardening

"Conceptualist landscape design is predicated on the idea of meaning, metaphor or narrative inserted into spaces." So writes the brilliant Tim Richardson in Avant Gardeners (Thames & Hudson £24.95). I think he may have saved my bacon. If I can just get my head (let alone my tongue) round a few words like chthonic and diachronic, I'll be able to stand by our patch of concrete with pride.

Metaphor is there in bucketfuls. The farmer who put the concrete down in the 1940s was probably more concerned with foot rot than metaphor but I'm training myself to see his intervention as a heroic but ultimately unsuccessful attempt to bring meaning to this space, to create a harmonious yet intellectually demanding linking passage between two acculturated verticals. The cracks in the concrete are quite brilliant, symbolising as they do the eternal nature of the fight between the now and the then, chthonic (I had to get it in – I may never have another chance) forces fighting to regain control of the space.

The concrete stands as a metaphor for man's arrogance. The cracks winding through it (very potently I think – I seem to remember a garden at Hampton Court last year that used just the same concept) represent the ultimate fate of all man's endeavours. This too shall pass. Oh yes, I could go on a lot about metaphors. But perhaps, in order to feel quite comfortable about this area as a valid piece of 21st-century gardening, I ought to stitch in a bit of narrative as well. The problem is, there's not much of a journey here – in a physical sense, no more than five paces in one direction, eight in the other. It is south facing...

No, no, no. Stop it there. I cannot, must not, am not allowed to think of this as a mere gardener might. If this space is to take its mimetic place in the pantheon of 21st-century gardens, the potential of its orientation can never be part of its worth. Shadows do interesting things on it, though. Do shadows count? Natural ones, I mean. Or are only man-made shadows allowed, filtered through lenses, manipulated by computer programmes? I fear so.

Perhaps, given that I fall down so badly on technical manipulation, I could bang on a bit about teleological tension: the way the particles of the concrete – the grit, the sand, the powdery cement itself – are at the same time individually suspended yet held together in a simulacrumic mass. Or is this going a little too far? I might be challenged. It's so tricky to be challenged when you, yourself, haven't the faintest idea what you are talking about.

But I'm sure there's narrative there. It just needs stitching together in a sufficiently diachronic (hurrah) way. Leaving aside the farmer, whose presence in the story is perhaps too empirical for my needs, the raw materials themselves can surely supply the narrative. Use of highly artificial materials is "one of the hallmarks of landscape conceptualism". So is "an insistent, repetitive, rhythmic visual sequence". I think I've got that too. Lucky old me. The farmer probably put the insistent ridges into the concrete to stop his cows slipping on their way to the milking parlour, but it requires only the slightest shift in perception to see them as rhythmic. Nice word, rhythmic. I'll enjoy saying that to myself as I pass through my conceptual garden on the way to the cold frames.

Meaning, Richardson's other requirement, is too easy to waste many words on. This patch can mean anything I say it does. I just need to assign semantic content with sufficient panache and confidence. Or I could adopt the stand taken by Martin Rein-Cano of the Berlin practice Topotek 1. "I don't believe in the idea of having to explain a design," he says. How sensible.

But am I missing a trick by not venturing a feminist take on the whole thing? History as herstory? The pervasive factor of gender embedded in the foliage that pushes, trampled but tenacious, between the cracks of the concrete? No, it won't do. I was brought up by a mother who treated with amused disdain the idea that women needed any special pleading. Such a disadvantage. I'll hang loose on meaning. It'll leave me free to blow with the wind of change.

My real problem lies in getting round that weasel word "inserted" that Richardson uses. Though the area I have been discussing seems to qualify in so many ways as a conceptual space, I cannot in any way claim to have inserted it. Nobody has paid me a large sum of money to bring it into being. I have not lain awake at night planning the exact line of those beautiful cracks, those insistent ridges.

I can't claim as the landscape architect Susanne Burger of Munich does, that my project planning "focuses the plain formulation of the design topic, always in connection with the explorable, empirical definition of space". Nor, like Jean-Pierre Brazs of Paris have I "found an architectural correlative in postmodernism and more recent deconstructivist disciplines". I must definitely go on looking. That correlative must be somewhere. Perhaps behind the door of the shed.

Meanwhile, I must stick at my homework and get to grips with the avant-garden. The snow has been a great distraction. It is far too beautiful to fit the script I am trying to write for my concrete topos. And it's gone and covered those really meaningful cracks.