Jun 18, 2015
More growers riding the kale production bandwagon

The popularity of a “green superfood” is catching the attention of vegetable growers in many regions of the United States, and the numbers show some dramatic increases in production in recent years.

Farmers produced nearly 60 percent more of the green in 2012 than they did in 2007, according to USDA.

In all, 2,500 farms reported harvesting kale in 2012, up from fewer than 1,000 in 2007. The state growing the most kale was California, where 390 farms harvested 1,680 acres in 2012, compared with fewer than 100 kale farms and 1,077 acres in 2007. Georgia ranked second and New Jersey third, narrowly beating Texas.

The 6,256 acres of kale harvested in 2012 still pales in comparison to the 130,000-acre broccoli yield. Even beets, with nearly 13,000 harvested acres, exceed kale’s numbers.

The ability to grow kale in a variety of colors has helped drive consumer appreciation, as foodies and chefs continue to join the bandwagon. The dynamic role farmers’ markets play in the food chain also has put kale in the spotlight in recent years. The majority of kale grown in the United States is certified organic. Season-extension techniques have enabled operators to grow kale in greenhouses, hoop houses and high tunnels to provide more seasonal market coverage.

Kale is making its way into the mainstream and into the fields of southwest Georgia, according to a University of Georgia (UGA) vegetable expert.

In the past, kale has been grown for use as a garnish for salad bars. Increased consumer demand in connection with its many health benefits has Georgia farmers planting, and selling, more of the leafy green, said University of Georgia Extension horticulturist Tim Coolong.

Georgia growers who have traditionally cultivated collard, mustard and turnip greens have now added kale.

“Consumer demand has increased, so large growers have been asked to grow it,” Coolong said. “They can sell what they’re growing, and because of the demand they can sometimes market it at a higher price point than other greens. If consumers demand it, growers will grow it.”

Kale is typically grown like other greens, making it easy for existing growers to incorporate it into their farming systems, he said. Kale has a similar flavor to traditional greens, and there are multiple ways to prepare it. Its growing popularity is linked to its perceived health benefits, according to Coolong.

“Researchers have focused on the impact of lutein levels in kale, with some studies showing that a lutein-rich diet, featuring vegetables such as kale, can help slow macular degeneration along with a number of other positive health attributes,” Coolong said. “Although many associate high levels of carotenoids with more colorful vegetables, kale has long been known to have abundant levels of carotenoids, among the highest levels of all vegetables.”

According to the National Institutes of Health, dietary carotenoids are thought to decrease the risk of disease, particularly certain cancers and eye disease.

“Leafy crops are good to eat, and other greens can be just as nutritious as kale,” Coolong said.

Judy Harrison, UGA Extension food and nutrition specialist, said kale has been grown for centuries, but its resurgence is due to a greater emphasis on healthy diets.

“I think the emphasis on eating more fruits and vegetables and including a variety of these in our diets has helped people rediscover kale,” she said.

Kale is a member of the cabbage family, contains no fat or cholesterol and is low in sodium. It provides an abundance of vitamins A and C, which Harrison said help ensure bodies work properly.

“Increased intakes of fruits and vegetables may help prevent obesity and may help to reduce risk of chronic diseases, like Type 2 diabetes, cancer and cardiovascular disease,” she said.

With such a high demand placed on kale, UGA researchers are evaluating a wider selection of varieties that growers may plant.

Seed supplies of some of the more traditional varieties have been short due to the increase in popularity, Coolong said.

“We’re still working on the variety trials,” he said. “Some new selections are working well, but we have only a few seasons of data.”

To incorporate kale in your diet, Harrison suggests adding it to stir-fry, using it as a smoothie ingredient or baking kale chips.

A fast-food addition

McDonald’s announced this spring that nine southern California restaurants are trying out breakfast bowls made with kale. One of the breakfast bowls is made with turkey sausage, egg white, kale and spinach, and the other includes chorizo and egg.

Other restaurant chains like Chipotle Mexican Grill, Jack in the Box and Taco Bell have helped popularize bowls over the years, which typically are made with meat or another protein, rice or another starch and vegetables.

McDonald’s restaurants in Canada were set to offer three salads made with kale as an ingredient, according to industry reports.

The move to incorporate kale by the fast-food giant began kicking in as part of a re-work of its menu, despite claims in McDonald’s advertising several months ago stating the vegetable choices on its menu “would never be kale.”

Easy to grow

USDA guidelines for producing kale categorize it as an easy vegetable to grow. It is generally more disease- and pest-resistant than other brassicas, although it can experience similar problems. Many specialty growers are planting kale in wide beds and harvesting it small as salad greens. In England, close plantings of kale have been shown to prevent aphid infestations through visual masking.

Kale can be grown almost anywhere where there’s a cool fall growing season, USDA states. It’s a cool-season crop, hardy to frosts and light freezes. Kale’s flavor is reported to improve and sweeten with frost.

The two main varieties of kale are Scotch, an early kale with deeply curled, blue green leaves (Dwarf Blue Curled), and Siberian, a later type with smoother gray-green leaves (Dwarf Siberian). There also are ornamental kales, grown particularly for garden display in late summer and early fall when the time for annuals has passed.

The ideal soil for kale is a fertile, well-drained loam. Clay types can be improved when supplemented with compost and well-rotted manure worked in to spade depth.

Kale germination takes seven to 10 days. It’s best to plant in midsummer for a late-fall crop. Growers plant kale in rows 18 inches to 2 feet apart. When the seedlings are 3 or more inches high, plants are thinned to 10 inches apart, and the thinnings are used for salads or as a cooked vegetable. Similar to collards, kale develops attractive leaves from a central stem, which grows a foot or so tall.

According to USDA, Kale can be harvested within approximately one month of becoming established. Leaf color is the best sign of crop readiness. Rich green leaves of firm texture are ready for cutting. If they are too dark and heavy, the leaves are tough and not as flavorful. It’s advisable to cut the leaves frequently to encourage new growth, but avoid picking the terminal bud at the top of the plant.

When cold weather begins, it’s advisable to mulch the plants with straw or salt hay, and they will continue to produce well into winter.

Similar to cabbage, USDA reports, pests that are troubling for kale include root maggot, cabbage butterflies/worms, cutworms and flea beetles.

Diseases seen in cabbage as well as kale include club root fungus, yellows, black rot and blackleg.

According to Oklahoma State University (OSU) Extension, kale is harvested when stalks are fairly young and tender. They should be clean and free of discolored and dying leaves.

Kale are typically hand bunched with three to five stalks per bunch. Bunched kale is usually washed and packed in bushel buckets, crates or cartons containing 24 bunches weighing 23 or 24 pounds. These greens are usually top-iced before shipment to provide a slow cooling method. Like all greens, kale has high respiration rates, making it very perishable.

Kale is not usually stored. If it is kept iced at 32˚ F, it will remain in fairly good condition for 10 to 14 days in fresh-market channels, according to OSU.

Gary Pullano

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