Keukenhof is a garden in the Dutch bulb country behind the dunes, and it is dug up and rebuilt every year. Each autumn seven million bulbs go in by hand, in three layers with the late varieties deepest, so as one wave fades the next comes up through it. The same square metre changes several times across the eight weeks, so a fortnight later you find a different garden on the same ground. Then the season shuts in May and the display is lifted. The name has nothing to do with flowers: the estate grew herbs and vegetables for a castle kitchen several fields away, and keukenhof means kitchen garden. Hyacinths are the loudest thing in the beds, and you smell them long before you reach them, especially on a still morning when the scent pools under the trees. In the pavilions the growers set out what a field never shows you: hundreds of named varieties side by side, from parrot tulips with torn green-flecked petals to the flamed ones that once made fortunes.
Outside the gates the bulb country is ordinary farmland, and the district is laid out for bicycles. Narrow farm lanes run between the strips, so the colour goes past at eye level on either side of you. The bulbs grow here because of what the sea left: old dune sand, pale and fast-draining, since a bulb rots in standing water. The tulip itself is not Dutch. It came from the Ottoman world, and within fifty years it had caused Europe's first speculative bubble, single rare bulbs changing hands for the price of a canal house before the market collapsed in 1637. The most prized of them, the streaked and flamed ones, owed their patterns to a virus that weakened the bulb. And the fields are not a display at all. They are a crop. Once a strip has shown its colour and been checked, the growers top the heads so the strength goes back into the bulb that is actually sold. A block blazing red on Tuesday can be plain green by Friday.