Back in the older days, when most people grew at least some of their food, if not all, they would notice that when certain plants or trees flowered or leafed out, etc, it was safe to plant certain vegetables.

For example: it's warm enough to plant corn when the leaves of the oak trees are as large as a squirrel's ear. Or, it's safe to plant peas once the crocus start blooming.

There must be a word for this, but I have never heard what it was, or didn't realize that's what it meant.

Thanks for any help!

Sue