The foliage doesn't hang around long, similar to a tulip in that regard. They do increase steadily in my garden, but not as prolific as daffodils.
I just realized I also grow C. leichtlinii Blue Danube too. I had forgotten about them because a spruce had overwhelmed the spot they were growing and had stopped blooming. They're in a new home and started blooming again this past spring. I would describe its growth and increase as similar to C. quamash.
A few years ago I discovered some growing wild near a stream bank while driving a back road near my home. I'm not sure what species they are, but I did snag a few bulbs for the garden. I guess that means I stole them, but there had been dozing work done that had exposed the bulbs- I couldn't stop myself, LOL.
Here is C. quamash this spring
This is the rescued roadside wildling.