Answer: Different varietiers of glad will bloom at different times, some are considered early bloomers, some mid-season, and some late. So if you planted them all at the same time, then you would see a succession of bloom.
If they are planted in different microclimates that could also influence the blooming time frame; in a cooler or shadier spot they would start later.
Size of the corm can also influence blooming. If you planted tiny cormels they may not be strong enough to bloom this year. Let these grow their foliage this summer and save to replant next year.
I hope this helps you trouble shoot.
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