Grow Your Own Powerhouse

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What two things do these 10 vegetables have in common?

Watercress
Chinese Cabbage
Chard
Beet greens
Spinach
Chicory
Leaf lettuce
Parsley
Romaine lettuce
Collards
If you’ve been keeping up with the news, you might recognize that these vegetables earned the highest ranking among 41 “Powerhouse Fruits and Vegetables,” based on a Centers for Disease Control and Prevention study published this past summer. Powerhouse Fruits and Vegetables (also known as PFVs) have a high level of beneficial nutrients relative to the amount of calories that they provide, and their consumption is strongly associated with a reduced risk of developing a chronic disease (like diabetes or cancer).

Table adapted from Di Noia J. Defining Powerhouse Fruits and Vegetables: A Nutrient Density Approach. Prev Chronic Dis 2014;11:130390.

Table adapted from Di Noia J. Defining Powerhouse Fruits and Vegetables: A Nutrient Density Approach. Prev Chronic Dis 2014;11:130390.

 

But there’s another common thread that may be even more important to home gardeners — they’re all cold-tolerant vegetables. Why, you could be growing them right now! And you could continue to be growing them through the middle of winter… without a greenhouse or fancy equipment.

Although the PFV rankings were released this summer, I only recently came across them while preparing a lecture at the medical school where I teach. I was immediately struck by how many of the top-ranking vegetables thrive in my home winter garden, but do relatively poorly if I try to grow them in the heat of summer. As discussed in the CDC publication, the top half of the list is dominated by cool weather-loving cruciferous vegetables (like Chinese cabbage, collards, kale, and arugula) and leafy greens (such as chard and spinach).

What about vegetables that can ONLY be grown in summer? None of them had a nutrient density score above 42! We may celebrate and extoll the health benefits of that first sun-ripened tomato in summer, but it doesn’t hold a candle to the nutrients in cold-tolerant watercress and spinach.

Plants that can survive through the winter express special cold-tolerance proteins, accumulate sugars, and modify their cell membranes to withstand freeze stress. Might some of these same chemical adaptations be responsible for the benefits of these plants to human health? It wouldn’t be a far stretch, given what we’ve learned about other plant chemicals like lycopene and resveratrol. Wouldn’t it be wonderful to later learn that winter gardening is not just possible for most of us, but healthier for us, too?

 

How to Grow the Top 10 PFVs

All of these vegetables are cold-tolerant, and the use of inexpensive low tunnels or cold frames could help you push their limits in plant hardiness zones 5 and above in the United States. Need more information? You can find more specifics in the “Winter Gardening” tab here on my website, or in my book recommendations that follow.

A low tunnel opened after the Polar Vortex of January 2014, contrasted with unprotected plants (below) and an unopened tunnel (above).

A low tunnel opened after the Polar Vortex of January 2014, contrasted with unprotected plants (below) and an unopened tunnel (above).

 

What to do if you’re in zones 4 or lower? I’ve found that most all of the top 10 vegetables grow well indoors, even if you keep your home thermostat below 70F (21C), and use ordinary fluorescent shop lights.

Watercress, which tops out the PFV chart at a nutrient density score of 100, is easily grown under fluorescent shop lights in a small flat of soil; at least three cuttings can be made from a single sowing, as long as you leave a generous amount of stem behind for regrowth.

The remaining top 10 PFVs also grow well indoors, but you can pack even more of a nutrient-dense punch by growing them in winter as micro greens. More on growing micro greens indoors is coming soon, so please make sure that you subscribe to my page using the form in the sidebar.

Ounce for ounce, these Garnet Mustard and Chinese Cabbage micro greens have more nutrients than mature plants.

Ounce for ounce, these Garnet Mustard and Chinese Cabbage micro greens have more nutrients than mature plants.

 

Additional Winter Gardening Resources:

These books are in my personal library, and I highly recommend them (these affiliate links cost nothing extra to you, but generate advertising fees that help me support this blog):

 

What vegetables could you be growing this winter? Check out this extensive list: my Winter Vegetable Planting Guide. And for more winter gardening resources from me, including how to build an inexpensive low tunnel, click the winter gardening tab above.

 

Web-based Resources

Not sure about your plant hardiness zone? Find out what it is here: United States and Canada

 

5 Comments

  1. Carole

    November 29, 2014 at 7:10 pm

    I didn’t get time to plant my winter garden this fall, when would you suggest planting in spring in a high tunnel?

    • Cathy

      December 4, 2014 at 3:51 pm

      Hi Carole. I haven’t done any high tunnel growing, but I can plant as early as February in my low tunnels here in Kentucky (and winter-sow some greens in January when space becomes available in a bed). It really depends on what you’re growing and what zone you’re in, and I’d be happy to help provide some guidance if you could supply that information. 🙂

      • Carole

        December 4, 2014 at 5:28 pm

        oops…I didn’t know I typed high tunnel. I really meant low tunnel.

        I am in zone 7b….near Raleigh NC.

        I would like to grow greens (spinach, mustards and Asian greens, collards, kale…etc) and then maybe creasy greens, mache, arugula and claytonia…too.

        I would like to grow carrots and beets.

        Earlier cabbage and broccoli and snow peas would be nice too.

        Thanks for the advice!

        • Cathy

          December 8, 2014 at 9:03 am

          The mache, claytonia, and creasies could all be winter-sown right now. Germination would be slow, though, so one trick that I use is to mix the seeds in a small container of potting soil, let them sit on the counter for a few days to stimulate germination, and then sow them outside. The remaining greens, you’re better off to wait until February to sow them directly in the tunnel — day length will be getting longer by then, and these others are more sensitive to light requirements in my experience. If you’re going to go for earlier cabbage and broccoli, keep in mind that you’ll need to start your own seeds indoors by January 1, as no garden centers are going to be offering them any earlier than April (at least in my neck of the woods). Carrots and beets are too late for a winter crop, but you can plant them in the tunnel starting in late February (though you may have to do the indoor-germination trick to help speed things along). Good luck!

  2. Ric Pullen

    December 17, 2014 at 6:36 am

    Thank you for spending your time helping those of us new to winter gardening. I gardened in the past but gave it up about twenty-five years ago due to a relocation. I am now retired and ready to garden again. I have put in three new raised beds and a small 10×10 greenhouse/potting shed this summer and I am just waiting for early spring to start seeds. I still have to build some cold frames but have row cover and supports ready to use. I look forward to the next four seasons of gardening and I have you to thank for that. Thank you for teaching an old dog some new tricks. You are an inspiration.