Planning is the key to success! This goes for everything in life, including lawn care. Some YouTubers preach the need to keep a lawn journal – a diary that documents what you've applied to your lawn and when.
I agree with this practice, but the project manager in me prefers to be more proactive. My approach (adapted from Grass and Garden TV) is to create a lawn care plan that can also act as a journal.
Each year, I create a one-page, colorized calendar that plans every aspect of my lawn care season. I break up my 30-week season into six cycles of five weeks each. Each cycle (other than mid-summer) begins with a fertilizer application. I also plan the timing of herbicides, insecticides and fungicides.
I print the calendar in color and keep it handy to jot down actual application dates and treatment details. Therefore it acts as both a plan and journal.
My calendar is designed for my 4-season climate in New Jersey, but you can easily adapt it for cooler or warmer areas by copying and customizing the Google spreadsheet to meet your needs.
IMPORTANT! The link below will open a read-only copy of my Google Spreadsheet. Use File>Make a copy… to save an editable copy of the spreadsheet to your personal Google Drive.
You cannot edit my file so don't ask for access.
Here's what my calendars looks like at the end of the season. Note the hash marks indicate when I mowed. R=rain.