In Season: Nicola Potatoes

When you think of powerhouse potato growing, states like Idaho and Washington come to mind. But at Heron Pond Farm, a full-diet organic farm just north of the Massachusetts border in South Hampton, New Hampshire, owners Andre Cantelmo and Greg Balog prefer quality over quantity, harvesting blue-ribbon heirloom varieties on five acres of their land. Modern Farmer caught up with Cantelmo in the cab of his blue Kubota tractor on a chilly November day, while he and his team were harvesting his favorite variety, the Nicola potato.

Modern Farmer: Why Nicola potatoes?

Andre Cantelmo: I love the Nicola. It’s one of the waxiest you can find and has one of the lowest glycemic indexes, which makes it much more like a sweet potato than a Russet, which is probably the worst potato you can eat as a diabetic. This is important to me because I used to be diabetic.

MF: What is difficult about harvesting potatoes in New Hampshire?

AC: Ideally, potatoes are grown in sandy soil. Here in the Granite State, we have really rocky soil, so cultivating and harvesting are difficult. The rocks need to be separated from the potatoes on the belt before the potatoes land in the wooden bins. Otherwise, the rocks can nick and bruise the potatoes and we can’t sell them.

MF: Why do you harvest this late in the season?

AC: We wait until now to harvest because we have a naturally cooling root cellar that needs to fall to 38 degrees for storage. In a perfect world, a potato’s internal temperature is 65 degrees at harvest time. They are alive and metabolizing when we harvest them so we try to bring down the internal temperature about 1 to 1.5 degrees every day until they get down to 38 degrees.

Potatoes like to live at 38 degrees and about 90 percent humidity with bottom air flow. In our root cellar, we try to mock what potatoes naturally do in the ground. We keep them in the dirt, in a dark and humid environment. In storage, you can actually tell that they are breathing; you’ll see wetness in the middle of the potato pile which is their exhale. This is why we need 90 percent humidity in the root cellar; they need enough moisture for their inhale, but not so much humidity that fungi grow.

“In storage, you can actually tell that the potatoes are breathing.”

MF: What’s the danger in harvesting at this time?

AC: Early ground freeze. If the internal potato temperature goes below 40 degrees it causes shadow bruising when you harvest. If there is an early ground freeze, you have to wait to harvest until the ground thaws for the day. Sometimes this means the harvest starts at 2 PM and ends four hours later when it’s too dark to see.

MF: How long does harvesting take?

AC: It takes about 15 to 20 minutes to fill a bin. Each bin holds at least 15 bushels of potatoes. We usually harvest 14 to 18 bins a day. We send about 1600 bushels of potatoes into storage and harvest countless others that are sold immediately between June and October.

MF: What are some unexpected issues that arise during the harvest?

The harvester we use is an ASA-LIFT from Denmark that was purchased in 1987. At that time, no one wanted small potatoes, so the belts had wider spacers. This presents a problem, especially when harvesting Nicola or fingerling potatoes because the smaller potatoes can fall through the gaps in the belt.

MF: Any other issues?

AC: Potatoes can get skin diseases like skirts, especially when they’re entering dormancy. Soft rots happen earlier and are the scariest thing to a potato farmer. The potatoes get yellow lesions and a gaping brown smelly rot that can happen in a matter of hours. We use an organic copper sulfite spray and try to plant resistant varieties.