What to plant as the climate warms

Jill Severn

A warming climate is changing what grows where.

In France, the traditional area for growing the grapes that become champagne are getting too hot. In England, they’re just now getting warm enough, so your next bottle of bubbly may be English rather than French.

If California’s weather and water woes continue, some almond orchards may be pushed into Oregon. And as Oregon warms, its filbert orchards may find their way north into Washington.

And amid all these shifts, we may need to depend more on local farms and gardens – and we will need to become more adaptable about what we grow.

We are already experiencing both rising summer heat and more unpredictable spring weather.

TJ Johnson, the proprietor of Urban Futures Farms, has stopped growing spinach because it needs cool temperatures, and our cool season is getting shorter. Johnson has replaced it with tatsoi, a more heat-tolerant Asian vegetable that can be used like spinach, and which his customers like as much or more.

He worries that more heat will mean trouble for lettuce and other salad greens, and for brassicas – all the plants in the cabbage family, including broccoli, brussels sprouts, cauliflower and kale.

“Peas also don’t like heat,” he says, and since cold, soggy soil made planting a little late this year, he’s concerned about what that will mean if June brings early hot weather.

But there is good news: some heat-loving vegetables that we couldn’t grow in the past can now mature here. Johnson has tried growing okra, a typically Southern vegetable. It grew well, but when it got close to harvest time, it succumbed to verticillium wilt – a soil-borne disease with no good remedy. But gardeners fortunate enough not to have that soil disease may get a good crop.

Johnson also tried growing sweet potatoes. They did well too, and ten days before their planned harvest, he expected to have about 100 pounds to sell. But voles foiled his plan by munching on nearly every one of them, leaving him with only ten salable pounds.

The only way to outsmart voles, he says, is to grow sweet potatoes (or lily and tulip bulbs) underground small-mesh wire cages – a solution that can be hard to manage on any but the smallest scale. For home gardeners, it might be an option. Any home gardeners who don’t have resident voles should count themselves lucky.

For gardeners who love sweet potatoes, being able to grow our own is a happy development. But it is one more reminder of our need to think about adapting to even more heat and unpredictable weather, with unpredictable consequences.

In the centuries since humans learned how to plant and grow our own food, no two years have ever had exactly the same weather. But in the years to come, the differences between one year and the next have become sharper.

During the heat dome of 2021, for instance, when the temperature hit 109 degrees, Johnson says he was out watering his 28 blueberry bushes several times a day. He had several different varieties. Now, two years later, two bushes have still not fully recovered; the rest are fine.

“Paying attention to variety selection is key,” he says. And that’s true of many crops, not just blueberries. Different kinds of salad greens, brassicas and peas may be in order too.

That’s why Johnson is starting to read seed catalogs from the South, including Southern Exposure, a seed exchange that includes many heirloom varieties.

Being open to growing more heat-loving crops, like sweet potatoes, okra and melons may also bring new delights to our tables. We might want to think of this as a “new normal.”

But as climate change advances, there may not be stable weather patterns at all if we don’t act to stop it. We need to do more than adapt. We need to act. We need to stop burning fossil fuels for our children's sake and all the plants and animals with whom we share this precious planet.

Jill Severn writes from her home in Olympia, where she grows vegetables, flowers, and a small flock of chickens. She loves conversation among gardeners. Start one by emailing her at  jill@theJOLTnews.com