North Country farmers and gardeners adjust to climate change, part 2

More annual precipitation is coming in heavy downpours. The Northeast leads the country with a 74 percent increase from 1958 to 2010. (Image provided — National Oceanic and Atmospheric Administration via the Northeast Regional Climate Center at Cornell University)

Much of what I know about gardening or have learned about farming is based on established practices (standards, rules, conventional norms) having to do with climate. Climate has always dictated which crops (and varieties) we can grow, which livestock we can rear, when to plant seeds or seedlings in the ground, which and when insect pests and diseases can be anticipated, and when to harvest.

But our climate is changing. We’re experiencing shorter, warmer winters and hotter summers. In fact, in 2012, the United States Department of Agriculture released updated plant hardiness zone maps which show that almost every region of the United States now has a longer, warmer growing season than just 25 years ago. North Country localities now range from as cold as zone 3b (minus 35 to minus 30 degrees) to as warm as zone 5a (minus 20 to minus 15), with much of the region upgraded from zone 3b to zone 4a. (Each zone represents a temperature range of 10 degrees, further divided into 5 degrees sub-zones “a” and “b.” This indicates that we now live in an area favoring a wider selection of crops than it did 25 years ago. And, while that may be true, there are several downsides.

Freeze risk

Fluctuating and often-unseasonably warm early spring temperatures are becoming more commonplace disruptions in what was once the normal freeze-thaw cycle and may actually be more damaging to perennials than colder minimum-winter-temperatures. Spring flowering seems to be advancing more quickly than frosts and freezes are losing ground. In backyard and commercial orchards, vineyards, and berry plantings, florae that bloom earlier are left vulnerable to frost and freeze damage. In recent years, late season freeze events have caused significant crop losses for fruit growers across the North Country and much of the Northeast. In fact, by some estimates, as much as 90 percent of the apple crop was lost to April freezes in areas of the Upper Midwest and Northeast in 2012.

Growers at every scale need to keep up to date with local weather forecasts and, before planting, do the research. Select proven varieties. And consider planting on a north-facing slope, if possible. South-facing slopes tend to encourage earlier leafing out and budding than north-facing slopes, which tend to delay the initial budding and minimize freeze-damage-risk.

Extreme rainfall and flooding

Much of the precipitation we now receive comes from increasingly-frequent intense downpours. In fact, the Northeast leads the country with a 74 percent increase in heavy precipitation from 1958 to 2010. Prolonged or extremely wet weather can delay planting and harvesting, promote erosion and soil loss, exacerbate soil compaction problems, and promote root damage and disease.

Gardeners need to carefully select well-drained sites on higher ground (or consider growing in raised beds) and varieties that have proven resistance to fungal and bacterial diseases. Farmers and gardeners should consider increasing soil organic matter. By some estimates, a 1% increase in soil organic matter will hold an additional 19,000 gallons of water per acre. Gardeners can add compost and other organic amendments. Cover cropping will add organic matter to farm fields and garden plots. Farmers can also reduce tillage, plant riparian buffers and, if feasible, invest in tile drainage systems.

Heat-stress and drought

While we are not facing the potentially severe future water shortages predicted for much of the nation, the risk of heat-stress events and short-term summer drought is expected to continue to increase; by most estimates, substantially. Heat stress and drought can lower the yields and quality of important, high-value grain (field corn, oats, wheat), vegetable (sweet corn, potatoes, brassicas), and fruit (apples, berries, grapes) crops.

Growers should consider diversification into newer, more-heat-resistant plant cultivars and, whenever possible, increasing irrigation capacity.

For dairy farmers (dairy is the dominant industry in the Northeast’s agricultural sector), even moderate heat stress (temperatures above 75 degrees with moderate humidity), can lead to considerable milk-production-decline. Investments to improve cow-comfort (additional fans, misters, or sprinkler systems, ventilation renovations), can be considerable. What’s more, all livestock producers are likely to encounter unpredictability in availability and cost of feed.

Diseases, pests and weeds

Milder winters and warmer summers have allowed insects, weeds, and diseases, which were once only marginally able to overwinter here, to flourish. New species (i.e. brown marmorated stick bug) invade and natives become more prolific. A longer growing season may also mean more insect generations per season.

Anticipating the challenge of increased weed and pest pressure, vigilantly monitoring crops, and rapid response will allow for more cost-effective management and better control, with minimal economic, environmental, and health risks.

Cornell’s Climate Smart Farming Extension Team

Cornell’s Climate Smart Farming Extension Team — a group of highly regarded individuals, each an expert in his or her field; work in partnership with Cornell Cooperative Extension and climate change and agriculture specialists at Cornell University to answer growers’ questions about management-practice changes that can be applied to help increase farm resiliency and sustainability.

To learn more, contact your local Cornell Cooperative Extension Association office or visit online.