Welcome to the season of fretting.

Having felt temps in the 60s, we no longer can complain about winter, yet can’t quite trill about spring. We may have lost our last mitten, but the sudden shift in temperature makes us fretful.

Do I need my parka? Or an umbrella? Sandals? (Too soon.) Will it snow again? Is winter really over?

Suddenly, strings of Christmas lights look a little desperate, like barflies who remain until last call. As much as we bemoaned winter’s pallor, there’s no beauty in snow’s early exit. When we hear “fifty shades of grey,” we think of late-winter landscapes.

Matted grass is plastered to the ground like a bad comb-over. The garden reveals a sodden ad circular touting Black Friday sales. Dog owners know better, but are nonetheless aghast. A perverse nostalgia for winter may arise.

Resist the urge.

Consider, instead, Jim Gilbert’s approach to the shoulder season. He’s a longtime naturalist whose notes on nature appear in newspapers, on radio and in his own books. He keeps a thoughtful log of what sprouts, sings or scuttles through his surroundings near Lake Waconia, bolstered by kindred observers around the state.

A woman in Swan Lake, for instance, let him know about a squadron of Canada geese that flew through on March 8, the year’s first recorded sighting here. Gilbert notes how red osier dogwood bark has started to photosynthesize, turning bright red.

“The veins of spring, I call it,” he said.

He revels in noting that mourning doves began cooing at 1:20 p.m. on March 6, or in sighting his first Eastern chipmunk of the year on March 5.

“There’s all kinds of things happening,” he said, even for more urban observers. “You can have melting in the street when it’s only 6 or 7 degrees above zero because the sun is so powerful.”

Perhaps the best sign of spring: Climbing into your car no longer calls to mind Robert Scott huddled in his Antarctic tent. You might even crack open the windows.

Winter’s work is done

Here’s the crazy thing about the first whiff of 50-degree air: People whose teeth chattered during last fall’s football games now are digging out their windbreakers.

We acclimate, just as plants do.

“Plants by this time of year have finished their rest period,” said Peter Moe, director of research and operations at the Minnesota Landscape Arboretum. Having achieved a crucial number of days below 40 degrees, silver maple buds can swell and crocus shoots emerge without ill effects.

“Cold-tolerant plants can stand an early spring, even with temps in the 20s,” he said. “That’s a risk they take.”

Problems arise when Zone 4 gardeners persist in dreaming of bougainvilleas growing alongside their zinnias. That is what Florida is for.

Moe said this is a great time to prune shrubs and trees as long as temperatures don’t remain in the 60s for a long time, when open wounds can spread disease.

“Maples will bleed, which doesn’t hurt the tree, but makes people feel bad,” he said. Keep the shears away from flowering shrubs, however, or you’ll chance clipping off the buds.

But — and you knew there was a “but” coming — we’re never entirely out of the North Woods.

Remember 2012, when St. Patrick’s Day revelers reveled in 80-degree record temps? It remained so warm through March that apple trees blossomed a month early. Then in early April, two nights of freezing temperatures devastated some orchards.

So don’t send everything to the dry cleaners just yet.

Spring needs to saunter in

Think pancakes. And waffles. And French toast.

The early warmth has set the maple sap to running weeks ahead of last year. At Somerskogen Sugarbush in Minnestrista, they started turning sap into syrup on March 11, compared with March 31 last year.

This isn’t the earliest that Don Somers has been able to tap, but neither does he want to see a repeat of 2012, when the weather stayed so temperate that the sap, somewhat counterintuitively, stopped flowing.

“We’ve already collected 300 gallons of sap from 900 trees,” Somers said last week. “The only disadvantage is that if it doesn’t get below freezing at night, the sap flow really decreases.”

By the calendar, the first day of spring is March 20, arriving at 5:45 p.m. Central Daylight Time.

In meteorological circles, however, winter is already history. Weather scientists divide the year into four three-month increments, with December, January and February accounting for winter. Spring is March, April and May. (You can figure out the rest.)

“The reasoning is that we’ve just finished the 90 coldest days of the year, statistically,” said Gilbert, the naturalist. “You can tell because there are just more sounds in the world.”

So the idea that spring already is here, with its coos and chirps and chattering chipmunks, is good news. Still, never underestimate Ma Nature: Now that we’ve experienced highs in the 60s, St. Patrick’s Day could feel brisk.

You can’t help but fret.