To expect the unexpected may be the best advice for gardeners facing unfamiliar weather patterns driven by a changing climate. But how do we do that?

Things are shifting, and the gardener’s focus must shift along with them, especially when caring for woody plants, said Daniel Weitoish, the arboriculture supervisor at Cornell Botanic Gardens in Ithaca, New York. Our updated job description is likely to require anticipation and triage, not simply scheduled maintenance.

“Rather than just looking at a calendar and saying, ‘It’s July 15, time to do X or Y,’ ” he said, we have to be “a caretaker, watching and reacting to what signs the plants are showing.”

Things are no longer happening in the order we’re used to, so we have to tune in for clues, and get to know the garden in this new world order.

“Being present, watching, knowing what to look for: It feels more intimate communicating with the plants and listening to their needs,” Weitoish said.

What signals has your garden been giving you? Take note — and take notes, for future reference, because not every symptom will coincide with a current weather event.

That’s another part of the equation, Weitoish explained: Trees are on a different time scale. They have “a metabolic memory,” he said, as if they keep “a budget or ledger of their reserves.”

Because of that, he added, “looking at what weather and climate and pests and stressors were like over several years goes a long way” toward understanding what we are seeing now.

Watering mindfully, creating shade

There are some important don’ts to remember when you’re dealing with stressed plants: Don’t prune them, and don’t fertilize, either.

If you see yellowing foliage, get it diagnosed with help from your county cooperative extension service. Don’t intervene without testing the soil. There has never been a more important time for gardeners to connect with expert hyperlocal resources.

Much of the tactical to-do advice seems obvious, but there is a new urgency — and less room for error.

It’s no surprise that a conscientious watering regimen is essential in gardens where erratic rain patterns and bouts of intense heat are becoming more commonplace. “We want rain to take care of watering, but if it hasn’t rained for a week or so, or if it’s been shallow drizzles, that’s when we start to take closer looks,” Weitoish said. “Dig a finger into the soil, and if the top 3 inches are dry, I’d start watering.”

You may have heard this before, but it bears repeating: Gardeners armed with a hose nozzle suited to car-wash0ing may be giving plants a bath, not a proper drink. Water infrequently but deeply, drenching the soil rather than the plants. Bark on trees and shrubs that is constantly wet can lead to decay; repeated watering on foliage contributes to fungal diseases.

Soaker hoses are an excellent way to put water only where it is needed. And make sure to do your watering at night or in the morning, rather than in the heat of day.

Mulch is another essential tool, both to retain soil moisture and regulate soil temperature. Cornell gardeners use mulch made from ramial wood chips (chipped small and medium-size branches) composted with fall leaves.

Better plant choices, smarter planting

Identify the areas in your garden that seem to have suffered the most in recent years. Some plants that used to handle full sun, for example, may not acclimate to a more intense version of it. Do you transplant them or modify the space?

At the botanic garden, a structure of slatted wood known as a lath house provides permanent shade for some plants, but there are simpler solutions.

Planting a coniferous tree on the southwest side of a garden can mitigate afternoon sun that’s harsh on perennials, understory trees and shrubs. “It’s probably not going to shade it this year,” Weitoish said. “But five years from now, you’ll have started to chip away at the problem.”

Until then, light-blocking shade cloth — woven polypropylene fabric available in various densities — could serve as a temporary rescue for small-scale plantings. Tarplike versions sold hemmed and with grommets are easier to set up on supports than unfinished material in rolls.

Although many of a gardener’s management decisions are made in response to weather — specific events at a given moment — it’s time to make some longer-term choices in anticipation of where the bigger pattern of climate is headed.

When a new U.S. Department of Agriculture Plant Hardiness Zone Map was issued in November, gardeners in half of the country learned that their locations had officially shifted. Many saw their average annual extreme minimum winter temperature (the metric the zones are based on) designated a half zone, or 5 degrees, milder, confirming something they had probably already felt.

Whatever the species, proper planting is crucial to success, particularly with all the additional stressors. The goal: maximum resilience.

“Take the time to do what’s best for the roots,” he said. Remove trees or shrubs from their nursery pots and spread the roots out, positioning them so that the root flare — where the first structural roots meet the trunk — is at soil grade or slightly higher.

Cornell team members are tuned in to all of this, but nevertheless undeterred. Just as they are trying out new tree species, they have also embarked on other future-thinking projects, including the installation of a water-wise gravel garden.

Hard times have prompted updated guidelines for drought preparedness and the like, certainly. But the outcome of recent strategic planning sessions wasn’t all protocols and procedures.

There was another important mandate, as well. “One of our essential values,” Weitoish said, “is to be purveyors of hope.”