I've been posting these in the Gardenbuddies thread in the Sandbox, and was informed that they might be welcome here.
We've naturalized several varieties of crocuses in our lawn, and normally get about a month of blooms before they're done. We leave the parts of the lawn where they grow alone, and don't mow until the crocus foliage dies back. Some years that can mean the first mowing there is like making hay!
The first photo is actually from 2020. I like the way the clover background makes the color "pop."
Area photo, taken March 11, 2021
A nice clump from March 11, 2021
Area photo, a few yards away, March 18, 2021
A nice clump from March 18, 2021
Winter aconites and 'Queen Charlotte' sweet violets, March 18, 2021
The European sweet violet (in this case, the 'Queen Charlotte' cultivar) are supposedly tender, but they have done well here in NE Kansas, and have colonized parts of the yard beyond where they were originally planted.