Garden Guy: Herbs past summer

Herbs at the grocery store. Photo courtesy Pinterest

By Bruce Bennett

Yes. It had to happen. Fewer hours of sunshine, cooler temperatures and time spent removing brown and yellow plants from the garden. 

Welcome to Autumn! And, with the changing of seasons, I have received several reader questions concerning what to do with their herbs. 

So, let’s spend this month’s column discussing over-wintering herbs and such. While there are several different types of herbs, we, primarily, use the annual, biennial and perennial ones. 

Basil photo courtesy OsoSeeds.com

Annual herbs, such as Basil. Cilantro and Dill, sprout from seed, flower, and die in a one-year period. 

Biennial herbs, such as Caraway, Chervil and Parsley, develop leaves and sometimes flowers during the first year, go dormant in winter, flower and set seed in the second year before dying. Woody, Perennial herbs, such as Marjoram, Rosemary and Sage, tend to live for years, if not decades. 

How these herbs are over-wintered depends into which group they fit. As we typically use the herbs’ leaves, let’s focus on those plants rather than the seed producers.

Annual herbs, such as Basil, Pineapple Sage and Stevia, complete their lifecycles between March and December. Attempting to keep them past summer’s annual herbs alive and productive is an exercise in futility and waste of your time. 

Instead, grow your own new plants from seed. Use a good potting soil rather than garden soil. Potting soil drains much better than the soil and contains no possibly harmful diseases. Find pots and a water-holding tray that will fit on your south-facing window sill. Windows facing other points of the compass can be used but may need the addition of grow lights to keep the herbs healthy and growing. 

Certainly, do read the directions on the back of the seed pack, but, in most cases, sprinkling the seeds on top of the soil, adding another quarter-inch of soil over the seeds and thoroughly water-in the pot is all you will need to begin a fine batch of new herbs for use over the winter months. Start some now!

Mint photo from blog.nurserylive.com

Perennial herbs are plants that live for a minimum of three years and, generally, longer. They are categorized as either woody, such as Sweet Bay and Oregano, or herbaceous perennials, such as Chives and Mint, respectively. 

Both of these classifications can also be divided into two main groups: hardy and tender/half-hardy. In Seattle, hardy herbs usually stay in the ground over winter. 

If the weather is forecast to be worse than usual, a two-inch layer of bark mulch or leaves placed over the root zones is appropriate protection. I continue to harvest the evergreen herbs, like Oregano, Rosemary and Sage, during the cold months for use in soups, stuffing and with meats. 

Pot-sized versions of these herbs can be moved from outdoors to that sunny kitchen window without too much of a problem. Remember to water them, but, let them dry-out a bit between watering. Misting will help them in the hotter, drier indoor settings. Herbaceous perennial herbs, such as Chives and Lemon Balm, can also be brought indoors and harvested all winter.

Half-hardy/tender perennials, such as Lemon Verbena, can be productive for many years. However, the secret to their longevity is bringing them indoors before the first frost as their hardiness usually doesn’t extend much below Zone 8 (the greater Seattle-area is around Zone 7 – 8). .

Biennial herbs are the easiest ones to discuss. The second year’s foliage of these plants tend to be less vigorous and tasty than when the herb was planted. Unless you are growing them for their seed, make your life easier and, at the end of the growing season; simply pull them as you would an annual.

Herbs - Drying - Photo courtesy
web.extension.illinois.edu

With all harvested herbs, remember to wash the plants in cool water and spread them on towels. Then, pat them dry with a towel. A sunny and well-ventilated room is an excellent spot for drying. 

You could also use frames covered with cheesecloth or other netting, or metal window screens with cheesecloth laid on top for drying. Prepare the frames or screens before you cut the plants.

For larger leafed herbs, such as Lemon Verbena, Lovage, Mint, Sage, and Tarragon, strip the leaves from the stems before drying. 

Then, spread these leaves in single layers for quickest drying. Herbs with smaller leaves, such as Oregano, Rosemary, Savory and Thyme, can be dried on the stems and stripped from the stems when dried. 

Herb leaves should dry in three to four days under proper conditions. Then place them in an air-tight container.

Herbs - Market - Photo courtesy
university.upstartfarmers.com

Some herbs do not dry well at home. Instead, you can freeze them. Handle them as you would for drying. 

Then after washing, blanch them in boiling, unsalted water for 50 seconds, cool quickly in ice water and blot dry. 

Spread them in a single layer on paper or cookie sheets and place them in the freezer. 

After the herbs are frozen, place them in airtight plastic containers or bags. Other options include using herbs to flavor vinegar or oil.

Considering just how pricey herbs are at the Farmers Markets or in the grocery stores, growing and preserving your own is not only a great cost-saving effort, it also makes for tastier meals and provides you with bragging rights when with family and friends.

If you have questions concerning this article or care to suggest a topic for future columns, contact Bruce at gardenguy4u@gmail.com. Happy winter gardening all!

Bruce Bennett, The Garden Guy

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Contributing columnist, Bruce Bennett, has served as a WSU Master Gardener, WA Certified Professional Horticulturalist and gardening lecturer for more than twenty years. 

He is the managing partner of a Seattle-area garden design company and is an instructor with WSU College of Agriculture, Human and Natural Resources