I was thinking about how some blooms and plants are the hallmark of certain seasons. Daffodils, Iris, etc. They consistently mark when certain events have happened. Last frost, start of the rainy season, and so on. In many areas, you can almost predict the exact day they will pop out of the ground and when the first flower will appear. I then got to thinking about how some of these traits were relied heavily on in times past. I know that I for one can't keep track of days and months well if I don't have a calendar handy or the internet screaming about important dates at me.
I wonder if anyone else has crafted a calendar garden based on the old knowledge of signal plants? A little patch of pretty flowers close to the house that appear in succession to keep attractive blooms all year, but which also serve to signal when the right time for certain plantings is or when to begin certain tasks. I have only done a passing scan of the internet about the matter so far, but did pull up this list of blooms based on the month of the year.
http://www.filoli.org/explore-filoli/the-garden/blooming-calendar.html
Do you know certain plants that are always marking specific moments in the year that are important or know of any bit of mostly forgotten lore regarding plants that mark predictable events?