Making green with microgreens

Growers have done with lettuce what craft brewers have done with beer. Spurred by changing consumer tastes, and a trend toward healthier eating, growers are meeting the demand for new and interesting varieties of this leafy vegetable.

A good example of the push toward the novel is the mini-head lettuce. Varieties like Breen and Rhazes are not only tasty and interesting in appearance, but come in single serving portions — no more lettuce turning brown and slimy in the fridge.

“Chefs prefer smaller heads because they keep longer,” says Paul Johnson, owner of Kekela Farm in Kamuela, Hawaii.

Lettuce is the most valuable vegetable crop in the U.S., with sales of $2.2 billion dollars in 2010, according to USDA statistics (fresh tomatoes were a distant second at $1.4 billion). Although California is the largest grower of lettuce, the crop is increasingly being grown in all parts of the country, thanks in part to hydroponic and covered growing methods.
 

The challenge for growers

What growers face if they want to grow greens and make some green, is matching the market demand for a particular lettuce variety to the existing growing conditions and methods in their region.

“The trick is to go through the seed selections and see what does well in your environment,” says Johnson.

Anne Cure, of Cure Organic Farm near Boulder, Co., agrees. She harvests 300 pounds of mixed greens twice a week and sells to farmers markets, restaurants, and via CSAs. She says diversity in lettuce offerings is the key to not only meeting market demand but building “resiliency” into a farm. She proves her point by growing a nice selection of lettuces.

“Batavian lettuce is our go-to,” says Cure. “We use Pablo a lot.” Both Johnson and Cure grow some romaine lettuces, with Jericho being the favorite choice of both growers.

Uniform maturity, field holding ability and shelf life are the pillars of good lettuce seed selection, according to Lauren Giroux, vegetable production manager at Johnny’s Selected Seeds.

The relatively new Salanova lettuce offered by Johnny’s appears to meet all three criteria. Giroux says growers are reporting good success with this class of lettuce, which includes incised and cored types, that come in varied colors and textures.

Here again, Johnson and Cure are on the same page, with growing Salanova because they like the way it holds in the field and how it reduces harvesting time and is “less fragile to handle,” according to Cure.

Shelf life is also important, and doesn’t just apply to lettuce that is shipped long distances. Johnson grows strictly mini-heads of lettuce —10-12 different varieties — because they keep well on the shelves of the resorts he serves on the island.
 

Consumer’s tastes

Ultimately, growers need to cater to the changing tastes and whims of consumers, the folks who browse the farmer’s markets and produce sections of the supermarket and also those sitting down for dinner at a restaurant. Appearance is everything in the lettuce market and there are a lot of good looking choices for consumers.

“For baby leaf lettuce, diverse colors and textures make the most attractive mix,” says Giroux. This is particularly apparent in varieties like Red Sails and Firecracker, two eye-catching selections offered by Johnny’s. She says it’s sad, but consumers appear to care to a lesser degree about taste.

For leaf lettuce, it’s all about the dark green color in varieties like Green Ice loose-leaf lettuce from Jung or the perennially popular Black-seeded Simpson, offered by Burpees and others. The market-preferred dark green types will also have a glossy appearance versus a matte or dull look. This characteristic keeps a leaf lettuce looking fresh, according to Giroux.
 

Growing culture and potential problems

Lettuce is not immune to disease and insect problems. Be prepared to deal with downy mildew, which is closely tied to weather conditions and is an issue in California. Bottom rot can be a problem, says Giroux, particularly in humid areas and with lettuce varieties that have a flat bottom or base where air movement is restricted. Tip and internal burn is mostly an environmental issue and can strike lettuce that is growing so quickly it can’t take up the necessary calcium to support growth, resulting in browning of the leaves at the edges.

Red aphid is the primary insect that affects lettuce and is mainly found in California.

“We haven’t had much of a problem with aphids,” says Johnson. He says mildew can be a problem because it is wet where he’s located, which is about 3,000 feet above sea level. So he grows his romaine lettuce in a high tunnel to reduce exposure to the rains.

Growers must meet the demands of a changing marketplace. Johnson says he’s seeing a slight decrease in demand for lettuce as people try different things, but there should always be demand for a good salad.

Neil Moran is a horticulturist and freelance writer in Sault Ste. Marie, Mich.