Peaches depend on a few key elements to produce a crop: cold winters, a lack of frost after they bloom, and warm weather to ripen the fruit. In our peach orchard, you can see the affects of different weather on the different varieties every year. We have 25 varieties of peaches and nectarines; each one with its own specific harvest window that generally lasts for a few days to a week. The date of ripening is more or less determined by the date that the trees start blooming: the earliest fruit blooms in late January or early February, and the latest in April. Spring-ripening peaches don’t need as much cold in the winter to produce a crop, while the ones that ripen in late summer need the most.
There are peach varieties that ripen in late September, but we can’t grow those here because we don’t get enough chill during the winter.
On the flip side, early ripening fruit is more vulnerable to weather in the spring. Rain causes blossoms to rot and fall off, and brings diseases that affect the foliage. And bees don’t fly and pollinate them when it’s cloudy and wet. Wet weather just before harvest also causes problems, and thunderstorms that bring hail are devastating any time after bloom.
A hard freeze at any time after the trees have leafed out can destroy any green tissue: flowers, fruit or leaves. Very cold weather tends to follow wet storms, and the affects are similar. So when you lose a crop of peaches it can be hard to tell whether to blame the rain or the cold.
When we planted our first peach trees in 2006, our goal was to have as long a harvest season as possible. According to the nursery catalog, we could harvest from mid-May until Labor Day. Being vegetable farmers, we didn’t know anything about all the other issues involved. It was only after we planted the orchard that local farmers told me “You can’t grow early peaches here, it’s too cold and wet in the spring”. They predicted we would never get a crop.
And it’s true that there have been years that those four rows of early-ripening trees have been empty of fruit. For the most part, they have produced reliably and abundantly — especially during the warm-winter years when many other varieties in the orchard had little or no crop.
In trying to diversify our offerings our CSA subscribers by offering peaches for as many weeks as possible, it turns out that we also hedged our bets against both short-term local weather and global climate change.
Peaches may be the orchard crop most capable of adapting to climate change. That’s because there are so many varieties, adapted to so many different parts of the country. And the trees grow quickly — just 3 years to the first harvest. So as farmers recognize new weather patterns developing, they can take out trees that aren’t producing well and replace them with others.
As the climate warms, peach farming is expanding in areas where it used to be a marginal or risky. This year, part of the gap in peach supply caused by the weather problems in the Southeast will be made up by growers in New England, where the peach season is getting longer (even though a frost wiped out the crop there last year).
The biggest challenge for peach growers though, from California to New England, will be the availability of workers with the skills and experience to tend to the orchards and harvest the fruit. The vast majority are immigrants, and there are fewer people available each year. But that’s a subject for another newsletter.