Published Sep 11, 2013

Grinnell Heritage Farm – Production, Packing Shed and Recordkeeping

By Sally Worley

Andy and Melissa Dunham opened their Grinnell Heritage Farm to 70 visitors Thursday, August 22. Andy’s Aunt Janet is majority owner of the farmland where Grinnell Heritage Farm raises food, and Andy is the 5th generation of his family to farm the land.

Andy grew up on a livestock farm in NE Iowa. After college and traveling to Tanzania with Peace Corps, he established his own roots on the Grinnell farm in 2006. Twenty of the 80 acres are planted into certified organic vegetables. The balance is in hay and pasture. Andy: “Our farm has grown in accordance with our business plan. It is still growing at an intentional rate to reach a scale we believe is sustainable.” The Dunhams raise cows on their pasture in order to produce fertility for their crops.

Currently the farm employs 14 people in addition to Melissa and Andy. They sell their products through Community Supported Agriculture, at Iowa City farmers market and to several wholesale accounts. The field day consisted of a farm tour, packing shed tour and presentation on recordkeeping.

Tour tidbits

Andy attended a Xerces Society presentation at a MOSES conference and learned how we’ve eliminated habitat for beneficials, and that habitat needs to be in the field and permanent. Neighbor Dewey Murken planted seeds of little bluestem, big bluestem and Indian grass in the greenhouse, and then transplanted the plugs into two 1000-foot beetle banks on the farm. These beetle banks provide perennial habitat in Grinnell Heritage Farm’s vegetable fields. Andy keeps beehives on the farm to help with pollination. They also have habitat for native ground-nesting bees, who are more effective pollinators than honeybees.

Andy showed attendees plots where he attempted to conduct year two of a Practical Farmers’ on-farm research project, Quick Turnaround Summer Cover Crops. The idea of this trial is to determine which cover crops hold potential to put on enough growth between spring and fall cash crop successions to be effective. There was no germination among his cover crop plots due to zero rainfall. The experiment setup is similar to that listed in this research summary.

As we walked by Grinnell Heritage Farm’s pasture, Andy shared that the pasture is shot since there hasn’t been rain on the farm in two months. Typically the cows graze 16 paddocks and move every two days. Currently the cows are in the back paddock being fed hay while the other paddocks are recuperating. Meat from the cows is of good quality (I can attest- we had some for dinner that night). The Dunhams don’t advertise their meat for sale because they sell out without advertising. The main reason the cows are on the farm is for fertility.

Andy showed the tour his parsnip ‘lesson.’ He planted parsnips that germinated well. Due to incessant spring rains, he couldn’t cultivate weeds according to schedule. “I should have tilled in the field, but the parsnips were doing well, so I let them grow. The parsnips will be a good harvest for us, but now I’ll battle weeds in this area for ten years,” said Andy. The weedy parsnip field was indeed a rare sight at Grinnell Heritage Farm. Other fields were very clean, due to adherence to a weeding schedule from stale seedbed preparation before a crop gets planted to regular cultivation throughout the life of the crop to keep weeds from competing with cash crops or going to seed. Grinnell Heritage Farm relies on a mix of cultivators and with hand weeding with a focus on mechanical weeding.

Andy pointed out bindweed, a prolific weed from the morning glory family: “This was a weed of my grandpa’s in the 60s, and is still a weed now.” Bindweed is a nuisance because it reproduces both by seed and rhizomes, or underground stems. The weed will regenerate from remnants left in the ground when pulled.

Grinnell Heritage Farm transplants most everything into the field. This year they grew out around 250,000 plugs in the greenhouse. They have a long-term employee, Angel, who oversees greenhouse seeding. “We are fortunate to have him,” Andy said. “Everyone can weed, at least kind of, but not everyone can seed. He is very good at it.”

Everything planted on the farm is planted into beds that match machinery size. The bed system uniformity makes documentation easier as well. Every bed is labeled, and every planting and harvest is recorded by bed location into a binder. Not only is this required for wholesale accounts, it makes crop rotation easier and is important for organic certification.

Grinnell Heritage Farm uses drip irrigation for many of their crops. In some areas drip tape is on top of soil. In other areas drip tape is buried when the mechanical bed former creates a raised bed and lays black plastic. Andy does not save drip tape from year to year; he’s found buying new each year is more cost effective than paying labor to roll up old drip tape and patch holes the next year.

Andy had three suggestions to test watermelon ripeness: 1) if the stem attached to the melon has shriveled and shrunk and if the tendril at the first node beyond the melon is dead; 2) if there is a yellow ground spot; or 3) if, when tapped, the watermelon makes a “plunk” versus a “plink” sound.

When planting crops for the wholesale market, Andy selects ones that aren’t intended to compete with economics of scale of the likes of Idaho potatoes. Instead they specialize in crops like kale and Brussels sprouts that are hand harvested regardless of scale. “We are able to sell crops like carrots for a premium, even though ours are produced on a much smaller scale than most in the mainstream market,” said Andy. “Ours are grown for flavor versus shipping and aren’t really a comparable product.”

New packing shed

When Grinnell Heritage Farm outgrew its packing shed, they toured five farms of a scale they will someday be similar to and used that information to help design their packing shed.

They installed a walk-in cooler that has the capacity to store three semi-loads worth of produce. Andy and Melissa received a Farm Storage Facility Loan from FSA to fund the cooler:

Andy and Melissa are working to be prepared for when new food safety regulations are implemented. “Besides putting covers over our lights, we think we’re pretty close,” said Melissa. The packing shed is home to a barrel washer, where employee Jose can wash up to one ton of carrots in a day to grocery store quality if they don’t come in very muddy. The barrel washer works for a lot of other crops the farm sells.

There are two old dairy bulk tanks in the packing shed. When product comes in from the field, employees dunk it into cold water in these tanks to quickly remove field heat. The packing shed’s brush washer cleans more sensitive produce, such as eggplant, zucchinis and peppers. This was purchased from Iowa company Nolt’s Produce Supply. Andy: “If you grow produce and don’t know Nolt’s, you should.” The company is not online; call (641)228-4496 to request a catalog. Andy also recommended Knott’s Handbook for Vegetable Growers for any commercial vegetable farmer.

Andy and Melissa built a crew area equipped with lockers and microwave/break area. A white board lists daily activities, so if the crew doesn’t have to wait for instructions. The packing shed houses a restroom with running water. The hand-washing sink is located right outside the bathroom, better for food safety. Melissa has a nice office in the packing shed, close to production, and equipped with a charming play area for her kids. Water and electricity in the packing shed are run above the work area to prevent tripping over hoses and cords.

Soil and water are treasured resources on a farm. There is a floor drain in the packing shed buily to endure the weight of full pallets that drains into a settling basin outside the packing shed. Soil is moved from produce to basin and then is returned to the field. Building gutters drain into the irrigation pond.


Andy is the farming enthusiast, passionate and well-versed out on all things farming, from machinery to varieties and everything in between. Melissa, on the other hand, is a recordkeeping enthusiastic. Oftentimes farms are comprised of farming enthusiasts, but are light on recordkeeping expertise. Melissa’s interest and abilities on the paperwork end are key to any good business, especially farming, where the work is hard and inefficiencies eat into profit margins.

Melissa’s presentation on recordkeeping can be accessed here: PFI Field Day Presentation. Grinnell Heritage Farm keeps very detailed data. Not only do they know their own actual production history, good records are important for profit and loss analyses, organic certification, wholesale accounts, crop insurance, delivery coordination, tax compliance and more.

Every crop family is assigned a number to increase ease of crop rotation. They set their maps and production schedule before the growing season. On their spreadsheet, they have a column for seeding planned date, as well as one for actual planting date. This way, if circumstances such as weather get them off course, they are operating on real data. This simplifies transplanting, harvest, organic and wholesale documentation.

Melissa relies on pivot tables to extract portions of her master Excel document so people aren’t wading through the colossal master sheet for just a few pieces of information. Seeding sheets are printed out and placed in the greenhouse so employees can keep documentation current. Melissa backs up all their data dutifully.

On the Excel field map, three years of growing history are visible, recorded by month and year. When Melissa and Andy plan the field map for the upcoming season, the process involves a long piece of paper and Post-it notes before it’s transcribed into a tidy Excel format.

Wholesale accounts require labels with the lot number, which identifies where the crop was grown and when it was harvested. The Dunhams made labels by hand until they purchased a label maker. Melissa: “Now we can print 40 labels in 15 seconds.”

Hopefully, more farmers will learn to adore recordkeeping rather than be intimidated by it. Practical Farmers offers multiple events each year that highlights what farmers in Iowa and beyond are doing to create good data and financial systems for their farm businesses. In addition, we are partnering with financial experts to provide their expertise to Iowa farmers. Please check out website for upcoming events.