The Massachusetts chapter of the Northeast Organic Farming Association. NOFA/Mass welcomes everyone who cares about food, where it comes from and how it’s grown

Growing Organically Since 1982

Beating the winter blues with winter greens (and oranges, whites, yellows, and more)

Print Friendly Version of this pagePrint Get a PDF version of this webpagePDF

This article comes from the NOFA/Massachusetts 2017 Feburary Issue Newsletter

By Dan Bensonoff

Overwintered onions

All too often, I’ll visit a farm in late fall or winter to find their high tunnels without any crops growing. Many growers don’t have the time, energy, or experience to get a crop in after their main summer crop has bit the dust. But high tunnels are simply too valuable to be unproductive for a full season or two. With good crop planning and preparation, you can grow an incredible diversity of vegetables throughout the winter and early spring.

If you want to learn more tips and tricks to enhance your farm’s year-round high tunnel production, join us for an advanced seminar at Stonehill College on February 6 on organic high tunnel production featuring expert farmers Michael Kilpatrick and Andrew Mefferd. Learn more here.

Let’s take a look at some innovative strategies for making use of that valuable real estate during winter.

Overwintering Onions

Come springtime, when your customers are again hungry for fresh produce, having fresh onions ready as early as possible will provide you with an important market advantage. Whether you’re looking to please a chef or round out your (mostly leafy) farm stand offerings in May, you may want to consider adding some onions to your winter high tunnel rotation.

To overwinter onions, you’ll have to start your seeds in late August or September. The exact timing will depend on your microclimate, but generally speaking, you want to transplant your onions at roughly pencil-length, so plan accordingly.

Once you transplant your onions into the ground, be sure to put some hoops and regular weight (AG-19) row cover over them to provide another layer of cold protection. In the fall and early spring, when the days can still be quite warm, you may want to pull back the row cover occasionally to provide more sunlight and air movement for your plants. Ventilating the high tunnel itself is also essential on any sunny, warm days.

According to trials done by Johnny’s and UNH, the most reliable onion variety for overwintering is Bridger, a hybrid yellow onion. They’ll start bulbing out in early-mid May in most areas of Massachusetts. Don’t wait too long to harvest them or they may bolt on you!

Fresh Carrots Through Winter and Into Spring

If you want to have a reliable year-round market, having fresh carrots available is essential. Sure, you can grow storage carrots and offer those through the winter, but with a cold high tunnel (or even low tunnel) you can have fresh, juicy, newly-dug carrots throughout much of the winter. And with careful planning, you can be the first to harvest bright spring carrots with their lacy greens still attached in the spring.

To overwinter carrots in the ground, you need to be sure that they’ve done all of their growing before the “persephone period” arrives. The “persephone period” is what Eliot Coleman calls the fall/winter spread during which there are less than 10 hours of sunlight in a day. Without those 10+ hours of light, most plants will not grow.

So, if you want to pull fresh carrots during the winter, be sure that they’ve put on enough root by early November. In my neck of the woods, that means seeding your carrots in mid-late August. Then, once November comes around, you can begin your harvest or keep them in the ground. But be aware that they also make great food for voles, mice and other rodents in the lean winter months.

For a spring carrot harvest you’ll want your carrots to have a few true leaves going into the “persephone period” but without any bulbous root. If you seed them too early, the root may rot in the ground or the carrot may bolt in the spring. For zone 6 at our latitude, that usually means seeding in early-mid October and then harvesting the carrots in May.

Be sure to look for a hardy variety for these plantings. A few to consider are “napoli” and “mokum”.

Deep Winter Greens

The kiss of frost on a leafy green is not only a beautiful sight, it is also the harbinger of peak sweetness. While there may not be any growth while Persephone wanders the underworld, there’s plenty of flavor. There are literally dozens of greens that our climate can accommodate through the winter months. Most of them need to reach their harvestable size by early November, so be sure to keep that in mind when choosing a planting/seeding date. Since that doesn’t leave much time between a summer crop, like tomatoes, and your winter green, growing good-sized seedlings for transplant may be the best option.

Unlike most greens, spinach actually will keep growing even under low light conditions. You can either transplant or direct seed spinach in the fall up through October, or transplant seedlings in late winter for an early spring harvest. 

Whichever trial you’re implementing, be sure to take careful records of seeding date, variety, days to harvest, and quality of the crop at various points. If you have the space and time, it’s also helpful to do several successions of the same crop, with as little as one week between successions, to fine-tune your crop schedule for your particular microclimate.


Donate to NOFA/Mass

Become a Member

Subcribe to the Newsletter

-A A +A