Several years ago I planted a single bulb of L. radiata to check if it would be hardy in my conditions. It thrived and bloomed so I ordered and planted 3 more near it for a nice little grouping. After 2 years I still notice some real differences between these and the original planting.

They bloom 1-2 weeks later

Their foliage is thinner and lighter green

The midrib leaf lines are less distinct

I understand that there are both sterile triploid and fertile diploid varieties of radiata. Could this be the case here? They were all supposed to be the triploid form which is said to be more hardy.