Clumps of camassia, blooming their blue heads off on a rainy April Monday at Fort Tryon Park, the far North of Manhattan.
That's the Hudson and Jersey in the background; it's a spectactular site.
"Big" is a relative thing, but read on. There are only a few blue-blooming Spring bulbs—scilla, muscari, crocuses, hyacinths, and these early-early Iris reticulata, which, yes, grow from bulbs.
Hyacinths aren't worth it past the first Spring anyway, so let's toss them as being what they truly are, a splurge for municipal garden bedding.
In cost-conscious gardens, then, all the other Spring blues are ankle-biters: Four inches, six inches, tops. Except camassia. Shin-high, it's the giant among them. And it's staying power is unrivaled. When it likes you, or rather the land you have to offer it, it can self-seed to the horizon.

Here's a meadow-full in Idaho. How happy are we. (Read more, and see the picture even bigger, here @ Wikipedia.) Other species of camassia are even bigger blue, and can tickle your knees. Most important for me with my flatter-than-Holland land, they are exceptional in their easy-going approach to wet ground, even growing pond-side. That's my garden after Winter rains. Camassia are in my future.