In the nature garden of the author in Scherpenzeel (centre of the Netherlands) a number of Crocus species have been introduced. Of the species flowering in spring only three increased in numbers (also by seed) and ran wild in various grassland types (hayfield) and in ‘haylawn’ (hayfield in spring and lawn in the rest of the year): C. chrysanthus (Fig. 3), C. tommasinianus (Fig. 2), and C. vernus subsp. vernus (Fig. 1). In the Dutch Flora¹ C. flavus cv. ‘Luteus’ (Fig. 4), C. tommasinianus and C. vernus are mentioned as species running wild, but not C. chrysanthus. However, the latter species has been often introduced in urban areas and has run wild in verges and lawns. Of the Crocus species flowering in autumn only C. speciosus showed a light increase.