I’d never thought of a garden simply in terms of the number of different plants it can hold, but if you are a plant addict with a frustratingly small garden it makes sense. Logically, I suppose, they should all be tiny alpines. The true cottage gardener, though, thinks differently. Each plant must have a reason to be there. Being pretty or good to eat is important, but more important still is sentiment: who gave you the seed or where you took the cutting.
It is not only cottage gardens that have this dimension, of course. I dare say Louis XIV had flashbacks (guilty ones, I hope) of the gardens at Vaux le Vicomte he had plundered for Versailles. In botanical gardens it was all down on the dog-eared accessions cards in the old box files before they were transferred on to the computer. It isn’t the same: no more traces of compost or clipped-on postcards of the Ychang gorge. The memories, though, the history and the accumulated know-how are part of the gene-bank of every garden as much as the genes of the plants themselves. You can say of any place that its reality is as much in perception as in bricks and mortar. But of gardens this is doubly true: they only exist to be perceived.
A garden of any size, in fact, is as rich as the mind of its creator. Someone who is always curious, always acquisitive, will have a garden of many layers of meaning; something that a designer, however fashionable, can never offer.