Record-warm temperatures have made Utah’s March feel more like summer. That has some gardeners getting their green thumbs out early.
“As far as sales, they've been better than ever all winter long, because we had no cold weather,” said Brad Olson, owner of Olson’s Garden Shoppe in Utah County.
As customer demand has risen with temperatures this month, Olson’s shop had to purchase spring plants and supplies earlier than usual to keep up.
“We're caught a little bit off guard, because we're not stocked as good as we should be,” he said. “So, I hurried and ordered two semi loads.”
The store began selling cool-season veggies, such as potatoes and cabbage, at the beginning of March — a couple of weeks before it normally does. Olson’s team also kept busy with big landscaping jobs during a time of year when work typically slows way down.
“Our business has been in business for 80-something years, and I think this is the first winter that we've landscaped all winter and sold plants all winter,” he said. “Who knows what's going to happen. Everybody's a little concerned.”
Concerned, that is, about how the warm, dry winter may impact Utah’s summer. Much of the West has spent the past couple of months in the grip of a snow drought, as record-warm temperatures decimated the fluffy white stuff that stocks 95% of Utah’s water supply.
The freakishly warm weather rolled right into spring. On March 21, Salt Lake City’s daytime high reached 84 degrees — its warmest temperature for any March day since at least 1874. The city’s historical average high for that day was 57 degrees.
Provo and Cedar City also set daily temperature records March 21 with highs of 86 and 82, respectively. And St. George hit a record-setting 94 degrees on March 20, the final day of astronomical winter.
“Almost every plant I see is very, very confused,” said Victoria Xiong, an assistant professor with the Utah State University Extension office in Kane County.
Plants that require a lot of heat, such as sunflowers and cosmos, are already sprouting, she said, and will likely require extra care to survive the coming weeks.
Fruit trees are some of the most bewildered, she said, with apricots and peaches beginning to bloom, even at higher elevations. The stages between flowering and fruiting are an especially vulnerable time for the trees, so flowering early could set them up for potential frost damage.
“People need to be mentally prepared that they might not have an abundant harvest,” Xiong said. “They might not have a lot of fruiting just because the weather is so naughty.”
The March warmth might be just the beginning of this spring’s heat. Nearly all of Utah is forecast to see above-average temperatures from April through June, according to the latest seasonal outlook from the National Oceanic and Atmospheric Administration.
In 2023, the U.S. Department of Agriculture updated its plant hardiness zone map, which shows which plants work in which areas, to reflect warming temperatures nationwide. Utah’s average temperature has increased by 3.1 degrees since 1970, according to analysis from Climate Central, and most scientists agree that human-caused emissions are driving similar changes across the globe.
The warmth can open the door for planting frost-tolerant veggies earlier, said Katie Wagner, an associate professor of horticulture with USU Extension in Salt Lake County. That includes spinach, broccoli and other species listed as hardy or semi-hardy in the USU planting calendar.
“You could go ahead and maybe move up the timeline on those types of vegetables,” she said. “But I would be very careful and cautious with trying to plant very tender things right now, because we're really not out of the woods.”
Lows in the 30s and 40s can still stunt growth for delicate plants, such as peppers and eggplants, even if frost doesn’t kill them entirely. For those varieties, she recommends waiting until closer to the historical last frost date — late April or early May in Salt Lake City.
“Just because it's warm today doesn't mean it's going to be warm two weeks from now,” she said. “So, you have to be a little bit careful.”
The warmer weather has plenty of downsides for gardens, too.
Weeds may pop up sooner. Hot air increases evaporation from soil. And with less winter chill, some pests may not have been entirely killed off.
“We may see some insects and disease pressure this year that we don't always get,” Wagner said.
Gardeners can check USU’s pest advisory website to see what’s troubling plants in their area and learn how to deal with them, she said.
Other tips include covering ground with wood mulch to minimize evaporation loss and removing weeds so they don’t steal water. It’s also a good idea to wait to fire up sprinklers, Wagner said, because that helps grass roots grow deeper to withstand future droughts. The state offers weekly county-level recommendations for lawn irrigation schedules online.
The potentially hot, dry summer on the horizon may lead gardeners to make some difficult choices. In general, young plants usually require more irrigation than established ones, Wagner said. So, it could be hard to keep those baby plants alive and might end up costing gardeners economically.
“This is probably, in my opinion, not the year to be doing a lot of planting of really shallow-rooted types of plants,” such as pansies and other annual flowers, Wagner said.
