Every year when I am thinking about my last frost date (which averages April 25) I don’t look at the calendar: I look at the oak trees.
There’s an old saying that when the oak leaves are the size of little mouse’s ears, it’s safe to plant.
You may think that this sounds like an old wives’ tale. Call it what you want. I think it’s a farmer’s saying. And in the years before sophisticated technology and weather satellites, what did the farmers use? Phenology–the study of signs in nature.
Internet searches yield lots of different ways to use this for planting guidelines. There are all sorts of regional planting guidelines cued to the flowering of various local trees and shrubs–search for “farming guides and phenology.” To make it local, add your state or region.
As for me, I am not sure where I first heard the “little mouses’ ears” advice. But I have plenty of oaks and I watch them carefully. And, so far, the advice has been great–no frost after the oaks leaf out.
But of course, by the look of these oaks, I won’t be planting anything tender anytime soon!