Growing winter storage crops at Skinny Dip Farm

by Sanne Kure-Jensen
Ben and Hannah Wolbach of Skinny Dip Farm in Westport, MA shared their experience growing and selling winter storage crops at a Twilight Event for the Southeastern Massachusetts Agricultural Partnership (SEMAP). In the workshop, Hannah and Ben Wolbach explained their fertility practices. Farm soils receive mineral supplements as recommended by soil tests. Hannah and Ben plant winter rye and vetch cover crops after harvest for winter cover to improve soil fertility and organic matter. Fields that will be planted in summer for fall harvest will have spring planted cover crop blends of either oats or barley with peas, clover and vetch. Oats and peas will cover fields destined for early spring plantings because oats are generally winterkilled in Westport making spring bed preparation easy.
Crop rotation helps minimize disease and pest problems. Each year, four farm blocks are planted in cash crops. A fifth block spends a full year in cover crops and hosts four batches of Redbro or Cornish Cross chickens. Ben drags his bottomless chicken tractor  onto fresh ground once or twice daily. The dragging action lays down the cover crop.
Varieties
When planning for winter storage crops, Hannah and Ben select vegetable varieties known to keep well. Watermelon radishes are the farm’s best selling fall radishes. Last year’s Daikon radishes grew up to three pounds and were popular with restaurant customers. Green Meat radishes may be stored into the next summer. Ben also recommended China Rose radishes.
In fall, the farm offers a mixed basket of radishes to farmers markets. Bolero carrots are extremely sweet when grown in the fall, especially after a light frost. In Westport, MA, carrots can be stored in the ground under two layers of row cover. Hannah harvests 3/4 of her carrots in the fall and leaves the rest in the ground. Carrot shoulders are vulnerable to freezing so Hannah mounds extra soil over them. She digs carrots during a winter thaw or first thing in the spring before they bolt. Deer pressure can be high if the row covers tear or blow off. Hannah checks her row covers regularly.
The farm grows Hakurei turnips in spring and fall. Hannah said they also grow a local favorite, Macomber turnips. These mild turnips are traditionally eaten raw or cooked, mashed and served with carrots. Ben is trying Gold Ball turnips and Purple Top turnips and looks forward to seeing customer reactions this. Successful sweet potato varieties include Beauregard, Covington, Garnet and Jewel. Hannah and Ben sow celeriac in a greenhouse in March and transplant it to the fields in May. Parsnips are direct seeded using pelletized seed and thinned to 4” spacing. Regular watering is important to ensure germination.
Hannah and Ben try to grow storage crops in ideal conditions. They thin to proper spacing for each crop, manage weeds to avoid competition and water as needed using drip tape. They harvest root crops at their peak, not too early or after prolonged stress. At harvest, they remove and leave tops in the fields for mulch and compost. Root crops need careful sorting, bagging and storage.
Storage
After washing, careful sorting helps remove any bruised or cut produce. “Only healthy, undamaged crops can go into storage,” said Hannah. Properly cured potatoes and sweet potatoes may scab over a cut or bruise. That may make them saleable right away but will not allow not long-term storage. Hannah cures sweet potatoes for 4-7 days at 80 degrees F using a space heater in a closet. Crops with insect damage or holes in their skin will quickly fail. “Napa cabbage with spotting or any sign of rot will quickly turn to mush in storage,” Hannah added.
There is a lot of debate about whether to store washed or unwashed produce. Ben said their potatoes often go unwashed into 50 pound craft paper bags. He said, “We wash our carrots, beets, turnips and radishes, pop them wet into vented 25 pound poly bags and stack them like cordwood to the ceiling of our walk-in cooler.”
Hannah said the most important thing they do is to date their crops as they go into the cooler or storage area. For storage crops, she recommends using the last-in, last-out method.
Different types of vegetables need different conditions for long-term storage. Squash and sweet potatoes store best in warm, dry conditions. Alliums need to be cold and dry. Most other root crops last best in cold, moist conditions. “In late summer, most customers don’t want to buy new things. By February, they will buy just about anything,” explained Ben.
Hannah and Ben Wolbach have been farming together for nine years. Learn more at skinnydipfarm.blogspot.com or contact Ben and Hannah Wolbach at skinnydipcsa@gmail.com or 401-592-0237.