1994 Volume 63 Issue 3 Pages 629-638
Forcing abilities of spring-flowering Allium species were evaluated for possible inclusion in our breeding program for new ornamental Alliums. The inflorescences of A. schubertii Zuccarini and A. sphaerocephalurn L. withered prior to blooming despite exposure to various storage conditions and staggered planting dates in autumn and winter. A. aflatunense Fedtsch. and its cultivar 'Purple Sensation', A. caeritleum Pallas, and A. oreophilum Meyer required at least four weeks of moist winter storage at 4°C to bloom. Exposure to eight weeks of moist winter storage at 4°C improved the blooming percentages of A. giganteum Regel, whereas A. moly L. required 12 weeks of similar storage to attain 100% bloom. The treatments did not dramatically affect the blooming percentages of A. cowanii Lindl., A. neapolitanum Cyr. A. roseum L. and A. cowanii ; A. neapolitanum achieved 100% bloom without exposure to moist winter storage at 4°C. In A. albopilosum Wright, cold storage and later planting reduced the blooming percentage. Except for A. cowanii, A. moly, and A. neapolitanum, longer cold storage and staggered planting did not satisfactorily extend the blooming period of the other species.