John Bunker has spent the past fifty years learning everything he can about North American apple varieties.
"It's safe to say that by roughly the Civil War, that there were probably between 10 and 20 thousand named American varieties that were being grown one place or another."
Today, we have fewer than 5,000 named apples. But John says that as our climate changes, it’s more important than ever to do what we can to preserve and increase this diversity.
"In our orchard, we have about 450 different selections. And I believe that the health of any orchard now or at any point in history is going to be in its flexibility and diversity."
To explain why, John told me about an extreme weather event in May of 2023. The temperature all over the northeast dropped into the low twenties during bloom time for the apple trees and many orchards that season lost everything.
"We did not if it wasn't so much of a bummer, the fun part of it was that because we grow so many different apples, it was incredibly interesting and potentially useful to see which ones did well. And some were not phased by the cold at all. Others were wiped out."
John took notes that spring. And he’s been doing the same in the fall in recent years, watching how different apples on his farm respond to another new climate pattern he sees developing.
"The climate here on our farm is getting warmer. I've been here 52 years, 53 years. And we have longer falls, typically earlier springs, but certainly longer falls. The longer fall can be challenging for the apples because some of them decide that it's warm, so, you know why go dormant?"
Offhand this might not sound like a problem. The trees are photosynthesizing longer and storing more energy to make fruit. But when late October rolls around and these apples suddenly get hit by cold temperatures, it’s like they’ve been caught out in their bathing suits and some die. You might think this means we should be planting apples better adapted to warmer climates, but John says that actually it’s the apples best adapted to super cold climates that are surviving these swings.
"Some of the apples that do really well in the situation in our farm where temperatures are warming is the ones that are really hardy. Actually maybe we should be growing the ones that are hardier. And is that counterintuitive? A little bit, except that those are the ones that when September 21st and fall first arrives, they're like, okay, time to go dormant."
That’s because these varieties are relying on cues like changing daylight not temperature. Apples can survive extreme temperatures some as low as fifty degrees below zero but they need a cooling off period first, to slowly shut down respiration and put themselves into full dormancy. It’s when they don’t do this that they get winterkilled. And it's these counterintuitive twists that make John feels so strongly about both preserving old apple varieties and experimenting with new breeding.
"I don’t think that anyone knows what are the best apples to be growing now or in ten years or whatever but my recommendation is that there be people and I’m attempting to be one of them but there are others growing lots of different apples."
It turns out that yet again, diversity is the key.
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