`Four Seasons' is a moderately vigorous tree, with fruit that hangs for a long time. It flowers several times a year, with ripe fruit and flowers at the same time. Better than Meyers's lemon, which drops its leaves in an alarming way in autumn, a habit that gets worse as the plant gets older. Meyers's lemon is popular, thinks Chris Dennis, only because nurserymen find it easy to propagate. A 2ft-high `Four Seasons' lemon costs pounds 30.
`Tahiti', the lime you buy in supermarkets, is seedless, and the tree crops prolifically even when young. If you leave limes on the tree, they will turn yellow like lemons. The `Tahiti' has deliciously aromatic leaves and costs pounds 20 for a bush 1ft high. Keen cooks should go instead for the `Kaffir' lime which produces the leaves used in Thai dishes.
Of all the citrus family, the `Calamondin' is the most resilient to life on a windowsill. It makes an ornamental little plant with small, sour fruit like miniature oranges, which make good marmalade. It is very prolific, rarely without fruit or flower. A bush 1ft high costs pounds 20.