Fourteen popular bulbs: Allium christophii x 'Globe Master', Camassia cusicki,
Chionodoxa gigantea 'Luciliae Alba', Crocus vernus 'Flower Record', Hyacinthoides
'Excelsior', Hyacinthus orientalis 'Pink Surprise', Hyacinthus orientalis 'Atlantic', Muscari
armeniacum, Narcissus cyclamineus 'Tete a Tete', Ornithogolum umbellatum, Scilla
siberica, Tulipia 'Tarda', Tulipia 'Cape Cod', Tulipia 'Pink Impression' were planted in
Riverhead, NY and Griffin, GA in the fall of 2004. Four preemergence herbicides:
mesotrione, flumioxazin, oxadiazon and sulfentrazone were applied one week post plant
and twelve postemergence herbicides: sulfentrazone, carfentrazone, trifloxysulfuron,
clorsulfuron, metsulfuron, halosulfuron, 2,4-D amine, MCPP, triclopyr, clopyralid,
dicamba and fluroxypyr were applied in early spring 2005 to evaluate safety for potential
use in bulb or mixed landscape plantings. Overall, these materials do not show promise
for safe use on fall planted bulbs. Although some materials were safe on some bulbs,
no one herbicide was safe on all bulbs. In general, the spring-applied postemergence
materials were slightly less injurious except for Allium and the three tulip cultivars. Injury
symptoms worsened as the season progressed for both preemergence and
postemergence treatments. For most of the bulbs in which visual injury was observed,
bulb weight and bulb/foliage weight were also reduced as determined by a spring 2005
harvest.
