A few steps from my back porch, close to my kitchen and in a sunny spot of the yard, I’m growing herbs outdoors — in January. I use a simple season-extension device known as a low tunnel to harvest fresh herbs even in the coldest, darkest months of my Kansas climate.
Rather than digging up all the summertime herbs and transplanting them into pots for wintering over indoors (where herbs begin to look anemic after about a month), I use a low tunnel to protect the plants in my existing kitchen herb garden. My low tunnel is a rectangle of 3-mil heavy-duty plastic held above the herbs by a few hoops of CPVC pipes with their ends stuck into the ground. The edges of the plastic are held down with sticks and old bricks. Learn more about this easy DIY project in Low Tunnel Construction: How to Build a Mini Hoop House.
My low tunnel for herbs measures just 3 feet wide by 6 feet long. Inside are sage (only marginally hardy when unprotected in Zone 5b), parsley, marjoram, sorrel, two varieties of thyme and a few rogue seedlings of garlic chives. Often, in late fall, small dill plants will sprout inside the low tunnel. These short seedlings can survive all winter there, but typically last only a few weeks until I harvest them — and fresh dill from the kitchen herb garden in December is a luxury. Parsley plants started from seed in late summer can be transplanted into the tunnel in September, giving the roots time to establish before the first freeze. Other savory plants that can be harvested all winter from my low tunnel are sorrel and Egyptian walking onions. (I also supplement the tunnel-protected plants with rosemary grown in a container and moved indoors before the first frost.)
Any given winter, I save about $65 by growing herbs outdoors under a low tunnel’s layer of plastic. Here’s how I figure the savings: Small packages of fresh herbs cost $2.50 apiece at the grocery store. Every batch of homemade stock incorporates the equivalent of a packet of thyme plus a bunch of parsley. My homemade omelets are garnished with what amounts to a packet of sorrel. One of my household’s favorite dishes, pasta tossed with acorn squash, is dressed with a “packet” of butter-fried sage leaves. Christmas dinner alone can easily use up 4 or 5 packages of fresh herbs. If I had to buy all of this at a grocery store, it would cost $5.00/week, averaged out over 13 weeks of winter. Doing the math, that’s $5.00 x 13 weeks = $65.00.
Another benefit to growing herbs outdoors in the garden is the lack of the plastic waste from individually packaged store-bought herbs. Any waste from home-grown herbs ends up in the compost heap — and the heavy-duty plastic cover protecting my kitchen herb garden is reusable.
By growing my own herbs, I can also count on having varieties, such as lemon thyme, that aren’t available in many stores. Pungent flat-leaf parsley can be hard to find at the local shop, but it’s always on hand in my garden. Plus, store-bought herbs are often of poor quality compared with fresh herbs from the garden — even in the short days of January.
I encourage you to try growing herbs outdoors in low tunnels. You may have to experiment for a couple of winters to discover what works in your climate. Stick to herbs that are reasonably cold-hardy and that suit your cooking style and tastes. If you don’t use sage in your kitchen, don’t bother growing this herb inside a low tunnel — unless you want to impress your friends with garden-grown sage on your homemade pasta in the coldest season of the year.
(Top) My kitchen herb garden had a head start in spring after being protected by a low tunnel from record-breaking cold temperatures during winter 2013-2014 — eleven days were at or below 0 degrees Fahrenheit. Clockwise from top left: tarragon, turnip greens, chives, thyme, sorrel, parsley and sage.
(Middle) A simple sheet of plastic held up by hoops will keep herbs fresh and ready for your kitchen despite sub-freezing temperatures. From left: marjoram, thyme, sage and sorrel.
(Bottom) Store-bought herbs cost as much as $2.50 for a small packet weighing less than 1 ounce.