Plenty of hardy plants flourishing in this chilly, wet spring

By Karen Risch

It’s amazing to observe what grows in Ouray, a city of just a thousand people, living and working at an elevation of 7,500 - 8,400 feet. This hardy town lies in a sloping mountain bowl at lat/long 38°1′24″N 107°40′20″W, its citizens’ living experience enhanced by numerous hot springs, a river that never freezes, and warm pink and purple sedimentary cliffs.
In a cool, snowy spring like this one, many species of bushes, trees and vines flourish and flower in local gardens. Lilac, forsythia, spirea, Siberian pea shrub, mock orange, sand cherry, chokecherry, red twig dogwood, purple smoke tree and snowball bushes perfume the air with flowers. Apricot, apple and crabapple, sour cherry, plum, pear and peach trees bloom reliably here and often manage to set fruit as well. Hardy grapes, climbing honeysuckle and splendid, showy trumpet vines perform well in protected yard nooks.
As June begins, tough shrub roses ramp up the show. Harrison’s Yellow, also known as the Yellow Rose of Texas and the Oregon Trail Rose, was originally carried across the plains in covered wagons. It’s a scented, fruity, tall delight, spilling over fences and around trees. The pink flowering, purple leaved Rosa Rugosa bears little scent but makes a pleasing spray against a garden or house wall.
Another shrubby climber, the multi-colored Austrian Copper Rose, will flourish even — or especially with — neglect. My original specimen was dug from a patch of abandoned dirt at the edge of the Ouray School alley. A more sedate cousin, the showy pink cabbage rose, likes a moist, not too sunny spot near a west wall.
In the historical record, Ouray’s growing season averages 121 days, a pretty remarkable four-month duration, given the town’s mountainous location. But that’s just an average. In 25 years of keeping weather records, I’ve seen a 79-day growing season in 1995 and a 161-day growing season in 2010. The shortest growing season on record (76 days) occurred in 1985 and the longest (170 days) in 1958.
Ouray’s average last frost date (32.5 degrees) was yesterday, May 29; the average first frost date is Sept. 26. But that’s only an average, bracketed by two weeks either side where frost is likely to occur. So, we’re not out of the woods yet. (It’s May 30 of a very cool, snowy month in an El Niño spring as you read this!)
In fact, it’s not uncommon to see early June last frosts and early October first frosts. The earliest last frost date recorded is April 29, 2009, and latest spring frost occurred on June 27, 1985. The latest first frost recorded is Oct. 27, 1963. The earliest first frost on record is Sept. 3, 1961.
This year, though, Ouray’s gardens seem to be especially vulnerable as we move past the average last frost date. In the last two weeks we’ve had below freezing temperatures of 29-32 degrees on seven mornings since May 18, the last being 31 degrees on the 28th.
USDA climate zones span the country and are based on the average annual extreme minimum temperature. Ouray’s USDA zone is 6a with expected extreme minimum temperatures of -10 to -5 degrees. This makes the city a real anomaly, given its elevation. By way of comparison, Ridgway — 10 miles down the road at 6,985 feet — is USDA zone 5a with expected extreme minimum temperatures of -20 to -15 degrees.
Most years, Ouray doesn’t experience much in the way of below zero temperatures. This past winter, for example, had just three below zero nights: -5 and -4 on Jan. 2 and 3, and -1 on Feb. 20. The city’s usually dependable snow cover also protects the plants slumbering in our gardens.
Ouray shares this 6a climate zone designation with many and diverse places with longer growing seasons: Washington State, parts of Utah, northern New Mexico, Kansas, Indiana and southern New England.
Overall, May 2019 has been cool, soppy and snowy, but not especially record setting. In the first 28 days we recorded 3.40 inches of precipitation (normal is 1.76), but that’s paltry compared to May 2015’s record of 5.07 inches. Ouray’s 14.0 inches of snow this May is also dwarfed by a record 24.7 that fell in May 2011.
As of Tuesday, the 28th, this cool month accumulated temperature extremes of a measly 72 degrees on the 16th and 29 degrees on the 21st. Daytime temperatures have averaged 55.8 degrees, nearly eight degrees below the long term average of 63.5. Night temperatures have averaged 34.7, three degrees colder than the long term average of 37.7.
The 20th century Scottish poet Alice Mackenzie Swaim perfectly described this transition month and its impact on spring flowering plants and the hopeful humans who nurture them: “Courage is not the towering oak that sees storms come and go,” she wrote. “It is the fragile blossom that opens in the snow.”