Growing Culinary Herbs in the Piedmont

My chive bed this past April.

If you like to cook, you really need to grow your own culinary herbs. Even the stuff you buy “fresh” at grocery stores is a sad imitation of the real thing picked from your garden minutes before it adds zest to your latest dish. We are lucky in the southeastern Piedmont region of the US, because most of our winters are mild enough to prevent root kill to traditional perennial culinary herbs like rosemary, oregano, thyme, and sage. However, you need to remember a few key points to keep these herbs growing happily from year to year.

Growing herbs outdoors

Purple basil in bloom.

As with flowers, some herbs are annuals and some are perennials. Annuals die at the end of the growing season when the first freeze kills them. Common culinary herbs in this category include basil and dill. Most of the oft-used culinary herbs are perennials, which means the plants survive and expand from year to year. Herbs in this category include rosemaries, sages, thymes, and oreganos. True culinary tarragon is categorized as a tender perennial, meaning it is much more likely to die during a cold spell than a sage or a rosemary.

Even within the perennial herb group, some varieties are more tender than others. You didn’t think there is only one kind of sage or rosemary or oregano, did you? Rosemary cultivars alone number probably in the thirties or forties. Thymes come in a stunning array of growth forms and flavors, and even the sages and oreganos offer several distinct varieties.

Culinary sage in bloom this past spring.

Culinary sage today.

Regular culinary sage is indestructible in my garden. However, tricolor sage — a gorgeous plant with leaves sporting cream, pink, and purple leaves — never seems to handle our winter wet spells, no matter what I try. Purple sage has lovely lavender leaves with a milder taste than traditional green culinary sage. Some winters it survives for me; other years I lose it.

Greek oregano today. Note the late-blooming flowers to the left. Flower stalks are tall in spring, and draw every pollinator in the county.

Traditional culinary oregano is downright subtle compared to the in-your-face aroma and zing of Greek oregano. I recommend growing both. Greek oregano rocks home-made pizza. Both varieties survive winters well for me.

Rosemary ‘Salem’ in my front garden.

Happy rosemary plants grow into large sprawling shrubs in the Piedmont. This one in my front garden is about ten years old, and I hack it back regularly to keep it from overwhelming its neighbors. Some rosemary forms and varieties are much hardier than others in our climate. Prostrate rosemaries look fabulous draping over rock walls, but wet spells in winter always seem to kill mine when I try them. Some rosemaries have blue flowers, some pink, and some white. The leaves of some varieties smell like turpentine to my nose, but many are wonderfully sweet and resinous. The two varieties that survive best for me are Salem and Tuscan Blue.

An October rosemary flower.

My rosemary plants bloom at least a bit almost every month of the year, including mild spells in January. Pollinators adore the flowers, as they do the flowers of all culinary herbs.

You really need to see many of the rosemary cultivars growing together to appreciate their diversity. If you are near Chapel Hill, NC, visit the Mercer Reeves Hubbard Herb Garden at the North Carolina Botanical Garden.  They are the keepers of one of the Herb Society of America’s National Rosemary Collections, which means they — along with botanical gardens in other parts of the US — grow every distinct variety of rosemary known and keep records of bloom time, growth rates, etc. In late spring when all the rosemaries are in bloom, you can really appreciate their diversity.

Lemon thyme in bloom this past spring.

Like the rosemaries, thymes come in zillions of forms and flavors — everything from nutmeg thyme to orange thyme to traditional culinary thyme — and many others! Some are much easier to keep alive in the Piedmont than others. Of those varieties I’ve tried, lemon thyme and traditional English culinary thyme are the two that survive well with no help from me. I love them both.

This post is growing lengthy, so I’ll close with a few tips on growing these culinary necessities.

  • The herbs I’ve described today all originated in the Mediterranean region of the world. To keep them happy here, give them full sun and excellent drainage.
  • Never pamper these herbs. Fertilizer and extra water make them grow fast and leggy, and the essential oils that provide their flavor are diluted. A zingy herb plant in the Piedmont grows in hot, dry, unfertilized soil.
  • Don’t try to grow culinary herbs in unamended clay soil. Mediterranean soils are sandy/gravelly. Think rock garden. If your soil is red clay, build a raised bed and amend the clay with sand and a bit of compost to create a fluffy, fast-draining bed.
  • Mediterranean herbs hate our humid summers. Lower branches that touch the ground often develop fungal problems that sometimes kill the plants. My successful strategy to combat this is mulching with white pea gravel beneath the plants. The white gravel prevents branches from touching soggy ground, and the rocks reflect sunlight back up from the ground deep into the middle of plants, keeping them hot and happy.
  • Besides the white gravel, prune up branches near the ground, especially if they start looking sickly. This is especially important with rosemary plants. Don’t be afraid to prune herb plants. They just branch out and grow more.

Growing herbs indoors

Briefly, the secret here is to stop overwatering them. Really, everyone I talk to at the help desk at the NC Botanical Garden and anywhere else always seems to be doing this to their indoor herbs. Let them dry out completely between waterings, and keep them in your sunniest window away from drafts from doors or heating/AC vents. In other words, approximate Mediterranean growing conditions as closely as you can.

This goes for growing them in pots on decks and patios too. Don’t let them sit in large pots full of wet soil. They will not last long that way. Whenever possible, grow them in the ground, preferably near your house, so that you’ll remember to run out and pick fresh cuttings when you’re cooking dinner.

I’ll write more about growing herbs soon. I still need to cover the myriad basils and dills, not to mention parsley, bronze fennel, savories, garlic chives — and the list goes on and on.

Fresh pasta sauce with rosemary, basil, and oregano from the garden anyone?

Lemon basil blooming in the October vegetable garden.

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  1. #1 by MIke on October 19, 2012 - 3:15 pm

    The dogs came in yesterday morning, reeking of rosemary. Easy to tell which part of the yard they’d been running around in. The house smelled of it all day. Nice.

    • #2 by piedmontgardener on October 19, 2012 - 3:57 pm

      How nice for you, Mike! I’ve read that strongly resinous herbs like rosemary are supposed to repel fleas too. Perhaps your dogs were giving themselves a flea treatment. Then again, they may just appreciate the fragrance as much as we do. Thanks for stopping by.

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