ROANOKE, VA – The Virginia Association for Biological Farming (VABF) hosted its 23d annual conference recently. This year’s edition was one of the largest in its history, with over 500 attendees.

The event spanned three days and included several networking opportunities, a trade show with over 50 exhibitors and over 60 informative workshops, whose topics included growing heirloom varieties for commercial vegetable production; silvopasture design, implementation and maintenance; increasing diversity and resilience through multispecies grazing; and farming with vintage tractors.

The Taste of Virginia Expo & Market once again took place during the VABF conference. The expo allows local food and beverage companies to showcase their offerings to conference attendees, hotel guests and the public.

Dan Gagnon and his wife Janet Aardema operate Broadfork Farm, an organic produce farm with a strong CSA component in Chesterfield, VA. Both of them led workshops. The remainder of this story will cover Gagnon’s presentation on growing carrots year-round.

Broadfork Farm has been growing organic vegetables for over a dozen years. “Our carrot history has involved lots and lots and lots of troubles,” Gagnon said. Those tribulations led him to be “obsessed with solving the carrot problem,” he said. “Our troubleshooting skills were put to the test.”

To discover where the farm was failing in its carrot production, Gagnon and Aardema created a framework to understand the factors that go into production – not just of carrots, but any crop. They created the following list of factors: Variety, weed management, seeding rate, seeding depth, direct seeding equipment, bed preparation, germination needs, irrigation, fertility and how needs differ in different seasons.

Site and bed preparation is critical for carrot production. “Carrots first and foremost need deep, loose soil,” Gagnon said. At Broadfork Farm, the first thing they do is apply compost to the soil surface, then mix it in with a something like a tilther or a BCS with a power harrow. After that, they put out row markers.

“Weeding is super important with carrots,” Gagnon said, “so row marking is important.” They use strings to mark their rows. “It’s important that the distance between rows is uniform.”

For seeding, Broadfork uses a Hoss Garden Seeder. “Seeders work best on a flat, level surface,” Gagnon said. “If the bed surface has hills and valleys you can be seeding too deep or too shallow in various places.”

The seeding rate depends on what size carrot you want grow. For baby carrots, they plant 45 seeds/foot. For full size carrots they plant 20 – 30 seeds/foot. For storage carrots they plant 10 seeds/foot.

Broadfork Farm’s owners and operators Dan Gagnon and Janet Aardema have been raising organic vegetables in eastern Virginia for over a dozen years. For just about as long, they have been active in the VABF. Photo courtesy of Broadfork Farm

“Knowing the seeding rate is a great first step to understand what you are doing,” Gagnon said.

To calculate seeding rate, determine the number of seeds per pack (it should be listed on the package). Weigh the pack before you start seeding. When done seeding, put the remaining seeds back in the pack and weigh the partially full package.

The difference between the first and second weighing will be the weight of the seeds used. Determine the fraction of seeds used by comparing the initial and final weight, then multiply by the total number of seeds in the unopened package. The result will be the total number of seeds used.

Take that number and divide by the number of feet sowed. Then multiply by the germination rate to get to the number of expected plants per foot.

“Then observe,” Gagnon said, “to see if your actual results correlate to what you calculated.”

Row spacing is a critical factor in the success of carrot (and all vegetable) production. “At times I tried to maximize rows per bed,” Gagnon said. “In the humid Mid-Atlantic that didn’t do well – the crop was too crowded. A biointensive approach will work better in the early spring or late fall.”

Germination is an especially relevant factor for carrots, as they are, Gagnon noted, “notoriously challenging to germinate.” You want to plant carrot seeds at quarter-inch depth in spring and half-inch depth in summer.

“Soak the seeds as soon as you plant,” Gagnon said. Then cover the bed, either with row cover for 10 to 14 days in spring or white plastic for six days in summer.

Use sprinklers only for germination – after that, use drip irrigation. “Consistent water is needed for good root development,” Gagnon said.

When it comes to crop rotation, don’t grow carrots on carrots. “Carrots are light feeders,” Gagnon said, “so I plant them behind heavy feeders like brassicas, nightshades, cucurbits or onions.” It’s also best to plant carrots after a crop which had been well-weeded.

“I used to not plan,” Gagnon said. “Once I thought of carrots as being part of a larger rotation my success drastically improved – especially with regards to weeds.”

Broadfork Farm has developed a number of strategies for controlling weeds in carrots. First is that focus on reducing the weed population of the previous crop. Second is no-till. Third is application of compost to the soil surface. Finally, by covering the beds during germination it encourages weeds to emerge as well – but when the cover is removed the weeds tend to be leggy and either die off in direct sunlight or are easy to remove.

Two weeks after emergence, use a wheel hoe to cultivate, Gagnon advised.

Succession planting can be addressed in multiple ways. You can plant the same variety every two to three weeks, or you can plant different varieties at the same time with different maturities and different characteristics.

For spring planting, the team at Broadfork likes to get the bed prep done in early winter. Then they’ll plant on March 15, April 1 and April 15, covering the beds with row cover for 14 days. Those carrots will be ready to harvest in the June/July time period.

Carrots are a hard crop to grow in summer but if you want a supply of them in summer you can grow extra in spring and store them to distribute during the hotter months.

Broadfork sows carrots again on Aug. 1 and 15. Those carrots will be harvested October through December.

For autumn seeding of carrots, Gagnon uses Spinosad to control army worms. The carrots they sow in September (they plant twice that month, just like in August) are harvest-ready January through March. “Those carrots taste the best,” Gagnon said.

Using high tunnels will permit growers in the Mid-Atlantic to grow carrots over winter.

For more information on growing carrots or other specialty crops, check with your local Extension agent.

by Karl H. Kazaks