First frost comes too soon for many farmers, who need to keep cash flowing through fall and into winter. Marketing after the farm has finished producing requires the ability to store fall harvested vegetables. Depending on your scale of operation, there are sensible ways to store produce and make winter storage successful, not only in terms of economics, but also with the seasonal work load and employees in mind. Whether your farm is 4 acres or 25 acres or somewhere in between, stored vegetables can fit into your budget and your long-term plans for your farm. Here are insights into how three farms manage to extend their marketing season into winter with proper vegetable storage.

Spring Hill Community Farm
Spring Hill Community Farm is a CSA farm located in Prairie Farm, Wisconsin, about 80 miles northeast of the Minneapolis/St. Paul area. Mike Racette and Patty Wright, the farmers, grow about four to five acres of vegetables for their 140-share CSA. Starting this year, their 20-week delivery season begins in the third week of June, and lasts through November. They plan to have one optional delivery of winter-stored vegetables in December and will charge $35. Previously, their delivery season began two weeks earlier and ended sooner. Mike and Patty decided to shift their season to a later time frame because of work pressures in June. Weed control, transplanting, strawberry season, and the first CSA deliveries make June a very busy month. Since their summer help (high school-aged teenagers) aren’t available until the second week of June, it’s hard to get all the work done. For the last two years, about 70 people have signed up for their winter share. Crops they store include carrots, potatoes, onions, winter squash and pumpkins, garlic, cabbage, beets, and celeriac.

At Spring Hill Community Farm, vegetables are harvested and kept in a neighboring farmer’s cooler until November 1 or 15, depending on the weather. Mike and Patty wash all their vegetables directly after harvest, since they don’t have any washing facilities during winter. After cold weather sets in, they store their vegetables in an insulated room in their newly constructed community building. The room has a vent to the outside, which they open and close depending on the temperature. They aim for storing potatoes and onions at about 38-40 degrees F., and keep them in mesh bags on pallets. Carrots are kept in an old refrigerator, which keeps them colder and the temperature more stable. Warm temperatures in November (for example, the fall of 2001) caused some problems with this system, but by and large it works quite well.

Squash is kept in a separate room and held at about 50 degrees F. Mike and Patty move tables from their greenhouse into the storage building and cover them with a single layer of winter squash. The tables are constructed of 2 x 4s and snow fencing, so the squash has good air circulation around it at all times. A small electric heater and fan help to keep the room at an even temperature. Among the crops that they have grown, winter squash has presented the most challenges to the farmers. Crop loss due to spoilage has been high in some years. Among the varieties they’ve tried, ‘Festival’ has proved to be a real winner, both in terms of flavor and storage abilities.

The winter storage project is valuable to the farm for several reasons. First, the farmers feel that they are making money on their stored crops. Although they are fairly low dollar value crops, they are also low maintenance. In addition, they have a longer season of connection with their CSA customers, which boosts their retention rate. The June labor gap is also addressed with the shift to a later delivery season; towards the end of the summer timing is not as critical for harvest and fieldwork. Spring Hill Community Farm has found commonsense, economical methods of storing crops on a small scale.

Food Farm
Food Farm is a CSA farm in north-east Minnesota, near Duluth. John and Jane Fisher-Merritt, along with their sons Janaki and Ben and longtime employee Dave Hanlon farm about seven acres. They produce about 50 “winter shares”, a total of five deliveries–once per month during November-March. Members receive about 250 pounds of vegetables, including carrots, potatoes, cabbage, rutabagas, and parsnips for which they pay $215. Unlike many other farms, they chose to have a “root cellar” type underground storage location (about 24’ x 32’). The facility is built into the side of a hill, enabling easy access for unloading and loading root crops, and adjoins their packing shed. It cost $35,000 to build, and the farmers borrowed money from their CSA members to finance the structure. Since the area generates a $10,000 yearly gross, they feel it has already paid for itself in the short time they’ve had it.

To keep the vegetables cool, the Fisher-Merritts are dependent on outside temperatures to chill their vegetables. They wait as long as possible to harvest the vegetables—mid to late October for crops like carrots, beets and parsnips. Insulation keeps the root cellar’s temperature stable during both summer and winter. A two-inch thick layer of styrofoam is buried about 2 feet under the soil and extends 8 feet away from the building. Also, a styrofoam layer extends 2 feet down along the foundation of the building. This prevents the ground from heating up during the summer, and from becoming too cold during the winter. During the summer the area stays about 60 degrees F, and during the winter it’s about 45 degrees.
Because most of the vegetables they store require colder temperatures—close to freezing—the Fisher-Merritts installed ductwork and a computer monitoring system designed by Conservation Technologies in Duluth, Minnesota. The ductwork and computer cost about $3,000—a bargain compared with the cost of purchasing and operating a comparable-sized cooler. The computer monitors the temperature in each of the three rooms of the storage area, as well as the temperature outside. When it is too warm in the storage area and outside temps are cooler, the computer opens a vent to the outside, and fans blow in the colder air. The computer can also turn on a small electric heater if temperatures get too cold inside the storage area.

In terms of post harvest handling, the Fisher-Merritts wash all their vegetables before they go into storage. For them, it’s easier to wash the vegetables right out of the field. Defects are more visible on clean vegetables, which makes culling seconds straightforward. Instead of a barrel washer, they use a modified commercial clothes dryer to clean their root crops. Adaptations included removing the heating element and gearing it down so that the dryer turns very slowly, about one revolution every two minutes. Water sprays onto the vegetables from above to clean the vegetables and drains away through a 3” long slot.

The storage area has three separate rooms—one for root crops, one for onions and potatoes, and one for squash. After washing, the carrots and rutabagas go into storage bins made of wood and lined with plastic. The carrot bins are 4 feet long, 18 inches deep and 6 feet high. Bins for potatoes are 3 feet long, 2 feet deep and 6 feet high. The bins are constructed of 2 x 4s and plywood, and can be disassembled easily and cleaned at the end of the season. To prevent potential problems with carrots rotting, they line the bottom of the bins with two inches of peat moss, and layer burlap every 1 foot or so. The peat moss cushions the carrots on the bottom of the box and protects them from damage. The burlap is intended to prevent spoiled carrots from affecting the whole bin.

Like Mike Racette and Patty Wright, they’ve had significant crop loss with stored squash. The Fisher-Merritts cure their squash in a greenhouse for two weeks and then move it into storage. In the root cellar, the squash is stored on wire racks no more than two layers deep. A ceiling fan (the type used in homes) provides good air circulation. They caution against curing the squash for too long, thereby causing it to over-ripen.

At Food Farm, winter storage of vegetables makes sense because it shifts labor into the winter months. It also provides a year-round connection to their customers, who actually requested the winter shares as a way to gain access to better quality produce. Food Farm is a good example of winter vegetable storage for a medium sized farm.

To view photos of the storage facility at Food Farm, as well as graphs of wintertime performance, go to http//smfarm.coafes.umn.edu.

Tipi Produce
Located near Madison, Wisconsin, Steve Pincus and Beth Kazmar are larger-scale producers who grow 25 acres of vegetables. They market about 20% of their produce after November 1st, mostly to food coops, grocery stores and at one farmers’ market. Stored crops include carrots, rutabagas, turnips, parsnips, cabbage, onions and leeks. Carrots are their premier crop. They store produce for several reasons—it spreads out sales (as well as cash flow), is important for the continuity of their business, and enables them to employ some workers year-round. In terms of growing and harvest, they find that it’s easier to produce good quality crops later in the season. Most of their fall harvested vegetables are planted around July 4th, when weeds are not a major challenge. They can use the same equipment and spread out their work considerably, including tillage and cultivation, harvest, and post harvest handling.

Immediately after harvest, little is done to the vegetables, and they are stored unwashed. Steve and Beth do this for two reasons: first, the produce keeps better–washing abrades the roots slightly, providing an entrance wound for pathogens. Root crops also dehydrate less if stored unwashed. In addition, Steve and Beth don’t have time to wash the produce during the short harvest period in October and early November. During harvest, they like the soil to be as dry as possible so that less dirt clings to the roots. Currently they have a heated indoor washing facility that makes processing easier. Previously they washed vegetables in their greenhouse—a pleasant place on sunny days. For washing root crops they have a barrel washer that holds about 500 pounds of roots. Since the dried dirt is difficult to remove, they soak the roots in water for one to two hours before washing.

Leeks are harvested into plastic bulb trays, and the roots and tops are trimmed before they go into storage. Before sale, the leeks need to be processed again, the tops re-cut and one or more layers stripped off to present a marketable product. Cabbage is cut and any diseased leaves removed before storage. Before going to market, an additional layer of leaves can be stripped off if they dry down in storage. Neoprene gloves, available from Gempler’s for about $20, are a great help for keeping fingers warm during cold weather washing.

Most vegetables are stored in a walk-in cooler on a cement slab. The cooler is 26’ x 20’ x 8’ tall, and can store 40,000 pounds of vegetables. Potatoes and onions are stored in one area together, root crops in a separate area, and cabbage in a third area. Sometimes a heater is necessary to keep the vegetables from freezing in cold temperatures; fans provide some air circulation. Root crop vegetables are stored in wooden bins that fit on a standard size pallet for easy moving. Bins are either 40” long x 40” wide x 22” high or 40” x 48” x 24”. Cabbages, on the other hand, are piled on the concrete floor in bulk. Because of potential problems with rotting, they are stored as dry as possible without causing undue amounts of dehydration.

Preventing carrots and other root crops from drying out is a major challenge. Steve maintains the proper humidity level by spraying water on the walls and floor of the storage area. This is especially important in colder weather, since the relative humidity of the outside air is extremely low. Even when not much air circulates to the outside, the moisture seems to escape. Most of the problems with drying occur at the top of the bin. To help with this issue, vegetables are topped with a single layer of plastic.
Temperature is also an important factor. Stored vegetables are still technically alive, and respire and give off their own heat. Because of this factor, growers should store their root crops close to freezing. Although crops won’t freeze as fast as you’d think, it’s also important to realize that a full storage room will be warmer than a partially filled one. Steve and Beth have experienced some crop loss due to freezing around the edges of the storage area.

Since Steve and Beth work with large amounts of heavy produce, they have developed ways to manage lots of weight. Steve recommends that all new producers think carefully about this aspect before they begin. All of their bins fit on a standard pallet, and can be moved around with a pallet jack. They have also purchased clamp-on attachments for their front-end loader, which enable them to lift pallets and bins with the tractor. They purchased the pallet lifters through Market Farm Implement for $400 and declare them to be a wonderful investment.

At Tipi Produce, winter stored vegetables function well within the overall goals of the farm. Stored vegetables serve as a way to keep wholesale accounts active through the winter months. Valued employees are given employment through the winter months, and provide a core of experienced help for the following year. In accordance with a larger scale, time and money have been invested in making sure that production is efficient, using a walk-in cooler, pallet jacks and modified front-end loaders.

Does winter storage make sense for your farm? Perhaps so, if you have a concern about maintaining a connection with your customers over the winter. Another common motivation for growers is the need to spread out deadlines and their workload. You may need to do a bit of market research to determine the possibility for a niche market for winter produce. An insulated room in a pre-existing shed, or a basement storage area can provide an easy, low-cost way to begin experimenting with storage. It may take a couple of seasons before you make up your mind—but don’t make a final decision until you take a bite out of your first sweet and tasty February carrot!

Storage Crops
Producers often maintain different areas in their storage facility for different crops, since they require different storage conditions. Potatoes are often stored with onions and garlic.

Humidity and Temperature:
Onions and Garlic: Cool and dry (32 degrees and 60-65% relative humidity)
Squash: Warm and dry (50 degrees and 60-70% relative humidity)
Carrots, Leeks, Parsnips, Rutabagas, Beets, other roots: Cold and Very Moist (34 degrees and 95% relative humidity)
Cabbage and Potatoes: Cold and Moist (32-40 degrees F and 80-90 percent relative humidity)

Variety recommendations:
Beets: Cylindra, Lutz Green Leaf (most beets store well)
Cabbage: Dynamo, Storage #4
Carrots: Bolero
Winter squash: Delicata, Kabocha type, Festival
Potatoes: Gold Rush (a Russet type), Red Norland, Red Dale, Yukon Gold, Carolla
Onions: Copra, Frontier