Winter High Tunnel Crops Picking Up

Published: March 1, 2012

Last year I encountered a few growers in Clark and Prairie Home who were growing winter crops in high tunnels. The number has expanded this year, and the crops are still a selection of lettuces and salad greens. For this winter it has increased to three in Clark with tunnels planted completely full, and two partially filled. There are four growers in Prairie Home with tunnels full. A couple of growers in Clark were kind enough to share information about their experience.

These sales arrangements started with distributors approaching them for supply. Some outlets these distributors use are restaurants, direct to consumers (e.g. farmers market), and stores. In some cases these distributors are regular customers at the produce auctions and are looking to continue supplying the demand for local foods through the winter. It’s better to keep regular deliveries instead of totally shutting off their customers.

The market is driving what's grown, which is the fresh cut and washed salad greens that have become so popular with consumers and restaurants as 'ready to use'. This product is generally sold by weight. Producing a 'whole head' of lettuce would be possible, but that type of product is not being requested. Spinach and other greens are sometimes sold in grocery stores in 'bunches'; this also has not been asked for. Generally a bed is formed and then the crops are planted in several rows (2 to 4), and these crops may be planted individually, or as a mixture. A number of seed companies sell mixes for this purpose now, such as Morgan County Seeds and Johnny Select Seeds. These are some common plantings:

• Lettuce individually
• Lettuce as a mixture of varieties
• Spinach individually
• Arugula individually
• Beet greens individually
• 'Greens' as a mixture, e.g. kale, arugula, cress, leaf broccoli, mustard (red or green), and Asian greens like mizuna, tatsoi, Chinese cabbage, or Pac Hoi (baby bok choi).

Many times the price is the same across all products. The price is higher if the grower needs to wash and spin it dry. The price per pound that I have heard growers receiving varied from $3 to $8 per pound, with the higher prices being direct sale prices like at farmers markets.

Steven Kirk , Field Supervisor for the Commercial Vege-table Program at Lincoln University, stands behind a bed of mixed red and green lettuces in a Clark, MO high tunnel in early March.

Two or three crop cycles are possible in a given area. For three crops one will probably need to plant in early September. One can probably get one turn in the fall, plant again in late October or early November, harvest it in January and early February, and finish with a final planting to yield through March. With 3 crop cycles (as reported by a grower from Clark this year and last year from Prairie Home) the gross sales per square foot was about $1. For growers wanting to plant tomatoes early (e.g. mid February or early March), only two crop cycles are feasible. Some growers have tried intercropping tomatoes with lettuce, basically having a lettuce row on the outside edges of the bed, with tomatoes down the middle, with the final lettuce harvest being at the end of March or early April. This can work, but the initial tomato growth may be suppressed and there is a risk of transferring the primary lettuce insect pest to those tomatoes.

TAs compared to tomatoes, the input costs are quite minor.....some seeds, a little fertilizer like compost, if any. Some extra cash in the off season, little expense, so what are ‘cons’ to these ‘pros’? Time to harvest was mentioned, but with the qualification that they aren’t as busy in the winter. Two pests were bemoaned, aphids and chickweed. Surprisingly on aphids, a crop completely free of them isn’t needed, as they are washed out during that cleaning and spinning process. Keeping the production area as weed free as possible is the best defense against both. Grouping the beds into sections to till under at the same time will help with aphids, as they will have to move further to that new food supply. Perhaps the biggest risk is reducing or delaying the following crop yield, which is typically tomatoes, as the gross sales for that crop is $3 to $4/sq foot.

Clearly the demand for local foods is driving this market. Otherwise it would be easier to order in the product rather than travel the back roads in the winter for product that is relatively low volume compared to the April to October products. Opportunity with the customers at a number of produce auctions may exist. If some of those customers know that a number of high tunnel growers would be willing to produce through the winter, they might in turn see if they can find outlets to support the sales for some interested growers.