To make the sterile iris cultivar “Wedgwood” accessible to selection, bulbs were irradiated with X-rays. The aim is to induce flower colour mutations in this early flowering cultivar which is specially suitable for early forcing. The optimal dose turned out to be 1000 rad X-rays; the best moment for irradiation is immediately after lifting the bulbs in August when the growing points, which will form the new bulbs, are in the youngest possible ontogenetic stage. The size of the bulb does not seem to be an important factor. Since 1964 almost 6000 bulbs, representing approximately 25,000 growing points. have been irradiated. So far over 160 flower colour mutants, ranging from paler to darker blue with or without purple, have been obtained. Moreover, a number of other mutants — more flowers per stalk, other form of the flower or different flowering dates — have been observed. These results are discussed as well as other possible ways to reach the goal.