I diligently spent one entire season tracking when plants bloom for me which I now use as a reference guide. I used Excel and divided each month into 4 weeks across the top. For ease of reference, I used 1-7 as Week 1, 8-16 as Week 2, 16-23 as Week 3, and 24-30/31 as Week 4. Not precise, but close enough. As each plant bloomed, I entered its name on the left and colored in each square representing the week it bloomed as close to real as I could get. I also attempted to track the average weekly temp, general weather conditions, and added little pictures of earth events (first robin, frogs singing, dandelions blooming, last frost, etc.) up at the top as well. I initially colored in the entire bloom data section a very light gray so white blooms would stand out clearly.
I have not reproduced this project on a yearly basis, although I do occasionally add rows for new plants where they fall into the progression. It makes for a very colorful chart. If I could ever figure out how to do a screen shot, I'll post a pic.
I found that there was a definite palette of colors from season to season, and that often (but not always) really intense bold colors are short-lived. Other plants have surprised me by the really long length of bloom they provide.
