How many of our splendid spring bulb gardens will be transformed into

summer bulb gardens? Not enough is the answer. Now is the time to plan the change.

Most summer bulbs are planted about now. There are hundreds to choose from and I've picked out just a few of what I regard as mainstays of the summer garden. First I chose the dahlia, perhaps the most spectacular plant in any flower garden.

Even the end of March is too early to plant out dahlia tubers. It is much safer to start them in boxes or pots in unheated greenhouses, in a cold frame or even a sunny windowsill in the garage.

The time to put them into the garden is after the last frost, positioning them in the sunniest spot with a well-drained soil containing lots of organic matter.

There are literally thousands of dahlia varieties, from shin-high dwarfs to mansize giants in a myriad of colours and shapes. Remember to stake the tallest, pinch out overcrowded buds to get the biggest flowers and take them up for winter storage.

The gladiolus is another spectacular that comes in a rich variety of heights and colours. The most popular kinds are half-hardy hybrids which can be planted from early spring for display throughout summer. Like the dahlias, gladioli are best taken up in October for winter storage.

No such problems with the irises. Here is yet another huge and complicated family.

My choice would be the bearded irises, dwarfs, intermediates, and the tallest, which grow to a metre or more. They flower in that order, and provide a great sight as befits a flower named after the Goddess of the Rainbow.

The irises are hardy and should not be disturbed although the growing clumps can be divided four or five years after planting. They thrive in chalky soil which I know will appeal to a great many readers.

By Jim Roberts