Palisade expects 90% peach loss
A hard frost on the night of Monday, April 13, added disappointment to what has already been a challenging spring for Moab area residents. The cold temperatures may have wiped out a substantial portion of the local fruit crop.
April 15 has generally been known as the frost-free date downtown when it’s safe to plant garden starts. Any date prior to that is risky for young plants. Folks who grow lettuce and other frost-tolerant vegetables from seeds have already been enjoying the fruits of their labors. But fruit trees are largely up to the mercy of Mother Nature. And in Moab, early spring temperatures can often prompt a tree to bloom well before its blossoms and tiny fruits are out of danger from being frozen.
Michael Johnson, extension agent at Utah State University-Moab, confirmed the grim news: “Sorry, but it looks like this might not be a good fruit year,” he told The Times-Independent. “Due to the cold that evening, it appears there might be more damage to our fruit trees here in Moab. Good new fruit (which is very tiny right now) would be a nice shiny shade of brighter green, and blossoms would look healthy (if a tree is still in bloom). If the fruit is a pale to darker shade of green or you see any browning of the fruit or blossom, then it’s most likely damaged and not likely to produce. Unfortunately this warmer weather we often have in our area does make it more likely for fruit to be damaged when we have a series of cold nights or one very cold night,” said Johnson, an associate professor at USU-Moab.
What’s interesting about fruit damage is that it can affect some areas but not others, even within the same community. “Cold weather can be a bit selective,” he said, with temperatures dipping lower in cold pockets but not other places. “This is going to be area-dependent to some degree. If there is discoloring of the fruit from what it appeared a few days ago, then it’s been hit and will likely fall off the tree.”
Johnson further explained, “Damage to fruit tree flowers in late winter and early spring depends on the specific temperature and length of time it stays at that temperature. Generally, for most of our fruit trees, when at full bloom to post bloom (usually associated with petal fall), the temperature of concern is 28 degrees F. It is not just reaching this temperature but it must stay there for at least 30 minutes to damage the flower. At 30 minutes of 28 degrees F you could see 10% flower/fruit damage or death. If the temperature dropped to 25 degrees F for 30 minutes (or more) at this full bloom to post-bloom stage the expectation would be upwards of 90% or more flower/fruit death. Of course at temperatures in between this range that would vary, and when temperatures stay colder longer than 30 minutes you could see more flower/fruit death.
“For any fruit trees that had flowers still in the process of opening,” said Johnson, “the critical temperature drops slightly, meaning that it could take temperatures dropping to 27 or 26. But once flowers start to open there is more chance of damage with our late winter/early spring cold spells.”
Moab’s neighboring communities in the Grand Valley of Colorado are bracing for the worst. Folks who own orchards in Palisade, which is famous for its peaches, fear this will be their worst peach crop since 1999, according to the Grand Junction Sentinel. “I know we have an awful lot of damage,” said Bruce Talbott, whose family operates a number of orchards there.
Meteorologist Kris Sanders with the National Weather Service in Grand Junction said the low fell to a record 19 degrees the night of April 13 in Grand Junction, two degrees below the previous record set in 1933, thanks to an Arctic cold front.
Some farmers at commercial orchards in Mesa County utilized sprinklers and wind machines in an effort to mitigate damage. Buds that are surrounded by ice don’t get as cold as ones exposed to the bare air. The wind can move cold air along so that trees aren’t exposed too long.
But on Orchard Mesa, another area near Grand Junction, a research associate fears a near-total loss, according to David Sterle of Colorado State University’s Western Colorado Research Center. His associate, Ioannis Minas, expects 10 to 15% of the normal crop of peaches, he told the Sentinel. Minas is assistant professor of pomology, the science of fruit growing. “It’s a really dramatic loss. I think it’s one of the worst losses ever” for the local peach industry, he said.
Here in Moab, Johnson is holding out hope, explaining that some areas may have been spared. “Something to keep in mind is that beyond the temperature your thermometer showed, consider your landscape and how cold air might move through your property. Cold air is ‘thicker’ and heavier, and if your property is more open and you don’t live at a low place, the cold air will slowly move on past. However, if you have fencing, even as simple as a chain link fence, or shrubs or other items, the cold air can slow up and to a degree settle in place. This cold air is likely colder than the temperatures reported and can cause further damage,” said Johnson. “So even if outside temperatures don’t appear to be cold enough to damage your plants, cold air off the mesas can be much colder, settle in the area and damage your plants more than you might think.”
Fruit is likely even more vulnerable at higher elevations. Said Johnson, “In areas at a higher altitude it is possible more damage has occurred because we did have warmer weather, as is often the case, which pushed the flowers on our fruit trees to open up.”
Local weather recorder Ron Pierce did not report a killing frost at his weather station at 252 E. 100 N., on April 13. His gauge said it got down to 33 degrees F. On April 14 he recorded a low of 29 degrees.
But in Castle Valley, nursery owner Ken Drogan said it got down to 20 degrees F. This illustrates how various areas within a region, or even within a valley like Moab’s, can have a range of impacts.
Interestingly, Pierce noted these historic lows over the years: April 13, 1997 had a low of 24 degrees F. On April 14, 1933, a low of 20 degrees F was recorded. The last historical low on April 15, considered our frost-free date, was back in 1928.