By 'in' I assume you mean in the ground and not in a pot. Have you planted somewhere close to a tree or large shrub? Have you pruned it at all, and if so, when? Pruning should only be done in early April, as new growth appears, and then only to remove dead flowerheads and dead stems. Planting too close to a large shrub or tree results in dryness at the roots, another cause of non flowering.

To explain the April pruning, the flower buds for next spring form in mid to late summer, so pruning too late in the year (or in January) will cut off all of next years flowers.