The bulk of the growth in kale has been in salad mixes.

Of the 10 highest dollar volume kale stock-keeping units, mixes contributed 51% more to the rise in sales than cooking greens last year, according to Fresh Express.

As the health benefits of greens gained wider publicity the whole category rose in 2012, up 31.3% in dollar sales compared to 6.5% the previous year. But kale led the charge — up 151.5% compared to 55.5%.

Salinas, Calif.-based Fresh Express is the latest to promote those nutritional benefits with a product rollout, Baby Kale Mix. The 5-ounce bags also include chard and spinach.

It’s one of eight additions to the Fresh Express line that started shipping in August. Four are two-in-one, single-serve packs and two are chopped salad kits. Fresh Express added a bacon Caesar salad kit as well.

The single serves are separated by a perforation, a design that targets consumers concerned about keeping salads fresh or providing for more than one meal.

They include:

  • 50/50 Mix, a pair of 1.5-ounce bags featuring a variety of green and red lettuces plus spinach, radicchio, red bok choy, arugula and mizuna.
  • Baby Spinach in two 1.6-ounce bags;
  • Italian in a pair of 3.5-ounce bags with romaine and red cabbage; and
  • Hearts of Romaine in a pair of 3-ounce packs.

In larger sizes Baby Spinach, 50/50 and Hearts of Romaine have been Fresh Express’ top three products, respectively, in repeat purchases and household penetration.

The kits include:

  • Asian Chopped Salad Kit, 11.7 ounces with savoy cabbage, green cabbage, carrots, celery, green onions, cilantro, won ton strips, toasted sliced almonds and orange sesame dressing; and
  • Southwest Chopped Salad Kit, 11.4 ounces with green cabbage, romaine, carrots, green onions, cilantro, nacho cheese, tortilla strips and chipotle dressing.

Fresh Express is one of a number of shippers — others include Taylor Farms, Dole Fresh Vegetables and Mann Packing Co. — to add or introduce chopped salads to their lines in 2013.

Such products don’t seem to be draining sales from other stock-keeping units. More than 74% of consumers say they would purchase chopped kits in addition to their typical salad kit, according to a blind quantitative product taste test done in April by Tragon Research. A similar number consider the “chopped” category new and different.