Winter Greens: With season extension, local greens are available all year round

Greenery in the greenhouse at Landisdale Farm

Story and photos by Emily Teel.

When the truly cold winter weather arrives, it can throw a dedicated locavore into a panic. Sure, there are apples, root vegetables and potatoes to sustain us, but we crave fresh green crunch. Fortunately, to keep bringing fresh, green produce to market even when temperatures dip,  several area growers have invested in structures like greenhouses, where plants on tables benefit from active heating, and hoophouses, their less permanent cousins, where plants in the ground are protected by frames covered in clear plastic. These structures can’t mimic August’s growing conditions, but they can provide a hospitable microclimate for hardy greens like kale, collards and Swiss chard to keep arriving at farmers markets all winter long. 

Dan Landis grows some of the loveliest greens you’ll see all winter in his greenhouses at Landisdale Farm in Jonestown, Pennsylvania. He sells chard, kale, collards and dandelion greens regularly at the Clark Park Farmers Market. The 20 to 30-foot-long greenhouses accumulate warmth from the sun and are equipped with backup propane or wood-burning heaters but, according to Landis, “we only have to use heat if it really snows or something, so the house doesn’t collapse... It can be 30 degrees out, and on a sunny day it’ll be 70, 85 degrees in there... like Florida.”

Nonetheless, growing greens inside is very different than out in the fields. Though the houses capture warmth, they don’t change the fact that it’s winter. “January can be really challenging because the daylight hours are the shortest... We’ll harvest the largest leaves, but [they] just grow very slowly.” The difference in temperature and light “makes the plant slow down,” which means that he has to start the greenhouse plants early, let them get established and pace the harvest. Landis waits to begin picking in the greenhouse until the greens in the field are totally spent. As the cold sets in, “lettuce will go first. Kale and collards will pull through a freeze, [but] if it gets down to 22 degrees they may take on a weird color.” Only then will he shift to the greenhouse-grown greens. “Our kale and collards in the greenhouse are like our savings account... We have to try and make it last as long as we can... If you start picking them [early], you’ll be in trouble in January.”

Some growers are installing LED lights to mimic sunlight and increase production, but Landis doubts he’ll go down that road. “I’m fine if the stuff doesn’t grow as gives us a little bit of a break, too.”

But, however slowly, hardy greens do thrive in the houses. Since they’re growing out of season from their insect pests, they tend to look even nicer than field-grown ones. The plants might wilt a little more quickly because they are unaccustomed to changes in temperatures, but as Landis says with a shrug, “We don’t get complaints.” After all, locally-grown winter greens are still enough of a treat that they will likely be eaten up long before any wilting can take place. 

What to look for 
In the summer months, greens soak up sunshine outside and can grow to Jurassic proportions. Greenhouse-grown greens, on the other hand, grow more slowly and tend to be smaller and more fragile, wilting easily. Don’t be put off by this; these plants simply haven’t had to grow as strong because they’ve been protected from the elements. 
Nutrition 101
Dark, leafy greens like kale, chard, collards, mustard and turnip greens are some of the healthiest things you can eat. They’re rich in calcium, antioxidants, folate, potassium, beta-carotene and great-for-you vitamins E, C and K, so eat your cancer-fighting, skin-improving, bone-strengthening, digestive system-supporting greens. 


For The Cook 

Despite kale’s current popularity, when it comes to greens, people typically select the familiar and will resort to either sautéing them with garlic, or slow-cooking them with pork. While there’s nothing wrong with either, Rich Landau and Kate Jacoby, the chef-owners of acclaimed vegan restaurant Vedge offer a few other suggestions.

Chefs Jacoby (l) and Landau (r) of Vedge, 1221 Locust St., with a second location opening at 126 S. 19th St., spring of 2014“Greens are a dense food,” says Jacoby. “They can handle smoke, spice or strong acid.” And while spinach will wilt down to nothing in a hot pan, according to Landau, the “heavier, meatier greens,” that do well for winter growing benefit from two-stage cooking. Landau says the most important thing is that, “for the heavier greens, you’ve got to blanch them first.” To blanch, Landau recommends removing tough center ribs before giving greens a dunk in boiling water until their color goes bright, and then shocking them in ice water to stop the cooking process before draining and using. “When you’re at home it seems kind of ridiculous, [but] it tenderizes them,” he says “If you want to cook bad kale, throw it right in the pan. If you want to cook good kale, blanch it first.” 

If spinach is easy, and kale is intermediate, then Landau calls collards “the trickiest green of all.” For collards, Landau recommends julienning the leaves “like spaghetti.” To ensure that they cook well, “they need a little bit more braising... You do have to cook them past the point where you think they should be done... to get them tender.” When overcooked, they’re sulfurous and unpleasant, but when done well, Landau loves them. They’re “so meaty... They give so much flavor [and] it’s hard to recognize the flavor if you’re using it the wrong way.” At Vedge, a Moroccan-inspired version with smoked raisins has appeared on the menu, and Landau likes to stir-fry and quick-braise them with shiitake mushrooms, as in this recipe. 

From the kitchen of Chefs Landau and Jacoby

Collard Greens with Caramelized Onions and Shiitake Mushrooms
(Serves 2 as the main event or 4 as a side dish)
1 bunch collard greens 
(8-12 leaves)
15 fresh shiitake mushrooms, brushed clean
1 medium onion
1 clove garlic
1 Tbs. coconut oil
*  Serve with brown rice for a light supper, or with fried eggs for a hearty breakfast.


  • Wash greens and remove tough center ribs. Roll leaves and slice into ribbons the width of cooked spaghetti. Remove stems from shiitakes (reserve for stock) and slice caps into thin ribbons. Halve and thinly slice onion. Peel, halve and thinly slice garlic.
  • Bring a small saucepan of water to a boil over medium heat. Add collard greens and a pinch of salt, and stir to submerge. When the water returns to a boil, reserve a half-cup of liquid and drain greens in a colander. 
  • Heat coconut oil in a wok or wide frying pan (not non-stick) over high heat until it begins to smoke. 
  • Add onions and stir vigorously to coat in oil. Cook until onions begin to soften and turn golden brown, 1-2 minutes. 
  • Add shiitake mushrooms and stir vigorously to combine. Reduce heat to medium high and cook undisturbed 1-2 minutes. 
  • When onions and mushrooms are beginning to stick to the pan, add drained greens and garlic and toss to combine. 
  • Add reserved blanching liquid and a pinch of salt. As the liquid comes to a boil, stir and scrape up the caramelized layer at the bottom of the pan. Cook until liquid has evaporated and vegetables are coated with the reduced cooking liquid. 


For The Pantry

Besides ensuring that they cook nicely, blanching is a great way to transform a bunch of greens into something versatile that can be stored in the fridge for several days, or the freezer for several weeks. Jacoby recommends that “if you’ve got a bunch of greens from your CSA as big as a small child... blanch it ahead of time.” Simply pack it into a container and keep it in the fridge, or into a zip-top bag and freeze it. Once it’s blanched, “you can use it in different preparations... put it into pasta, throw it into soup... it’s ready to go.” 


An alumna of Fair Food, Philabundance and Greener Partners, Emily Teel is a food freelancer profoundly dedicated to sustainable, delicious food in Philadelphia. See more of her work at