Several possible reasons:

Too young, takes around 4 years to flower
In a position where it gets early morning sun in February March time which means if the buds have been frosted they will then drop off (it isn't the frosting that is the problem but the sun on the frosted buds)
No in acidic soil

If you join GoY Guest you will be able to respond to this reply and let us know if any of the above apply

Hi Guest,

This is a bit of a "how long is a piece of string" question...some info, at least, is needed on how and where the plant is being grown.

Also, is it a Magnolia or a Melianthus that you are enquiring about? If a Magnolia then the species/variety makes a HUGE difference. Some can flower at 1 year from being propagated whilst others take 20 or more years.

Shoot, I hadn't noticed that Ilex!