A rosemary bush by the kitchen door and a clump of chives by the porch step look the same in July as they do in the first week of snow, and that is the whole appeal. The plants that stay put outdoors are the ones that keep a cook from buying a plastic clamshell of herbs every other week.
Oregon State University Extension, in its guide to five cold-hardy herbs to grow at home, names 5 of them: parsley, rosemary, chives, thyme and oregano. The page carries no publication date, so it reads as lasting garden advice rather than news. Each herb comes with its own catch, and a few of those catches are where other sources disagree.
Parsley Is a Biennial That Can Last Close to Two Years
Oregon State describes parsley as a biennial, a plant that completes its life cycle over two years, and says that in a protected spot it can supply leaves for close to two years. The leaves turn bitter once the plant flowers. The flowers do last well in a vase and help pollinators, the guide adds.
Starting it is the slow part. The extension says parsley seed is hard to germinate and needs patience, and the plant has a taproot that does not transplant well. After the seedling stage it is easy to grow. Wikipedia backs the biennial label and says the taproot stores food over winter, with a flowering stem arriving in the second year.
Oregon State also says parsley dries poorly and recommends freezing clipped leaves in ice cube trays. Frenz Hub has a guide on how to freeze fresh green beans to enjoy all year for anyone clearing freezer space for the trays.
Rosemary Stays Evergreen but Hates Wet Roots
Rosemary is evergreen and supplies leaves all year, according to Oregon State. The extension says older plants are especially cold-hardy and that the plant likes a sunny southern exposure, but soil has to drain well even in winter. Its warning is blunt: “wet feet” is death to rosemary. Frenz Hub’s piece on elevated garden beds for fall greens, herbs and small patios covers one way to lift roots out of soggy ground, and its 7 xeriscaping ideas cover dry-soil planting.
Here the sources split. Illinois Extension’s Garden Scoop post of Nov. 2, 2019 says rosemary will not last the winter outdoors in central Illinois and should be potted and brought inside before the first freeze, ideally to a bright spot cooler than the house. Wikipedia says the plant is reasonably hardy in cool climates and that the ‘Arp’ cultivar can survive winter temperatures down to about minus 4 degrees F. The two are not strictly in conflict, since hardiness depends on cultivar, plant age and drainage.
Oregon State notes that rosemary is hard to grow from seed, so buying a plant is advised. Its woody stems can serve as kabob skewers, and the herb is easy to dry. A potted plant is also a candidate for the things never to be left outside through the winter list on craftingyourhome.com, depending on the climate.
Chives Disappear in Winter and Return First in Spring
Chives are the honest member of the group. Oregon State says they are cut back in fall and unavailable over winter, yet they are among the first plants to show growth in early spring. Once established, the plant gives a long-term supply of mild, oniony flavor, and its edible flowers work as a garnish for salads and soups. Fall cleanup in the garden shares the calendar with other outdoor chores, such as the ones in craftingyourhome.com’s list of 5 things never to do with a winter firewood pile.
One harvesting rule matters. The extension says to cut all the way to the ground, because half-cut leaves do not regrow, while full cuts are replaced by new growth. Wikipedia classes chives as a bulb-forming perennial that regrows from its bulbs each year, and the same page places them in the genus with onions and garlic.
Thyme Hardiness Depends on the Variety
Thyme is a low-growing perennial that suits a rock garden, and it blooms in spring and fall, Oregon State says. Cold hardiness varies by cultivar, so the extension advises choosing varieties noted as hardy for the area, and it calls for well-drained soil. Easy to grow, easy to use in the kitchen and easy to dry is how the guide sums it up.
The USDA Plant Hardiness Zone Map, the 2023 edition, is the standard tool for matching a variety to a yard. It rests on the average annual extreme minimum winter temperature and divides the country into 10-degree F zones and 5-degree F half zones. Wikipedia calls common thyme the most commonly cultivated culinary species and says it tolerates drought well, which fits the extension’s call for dry, drained soil.
Oregano Goes Dormant and Wants a Warm Spot
Oregon State says oregano is similar to thyme but slightly less hardy. It needs a sunny location and benefits from the soil-warming effect of a rock garden, and it goes dormant in winter. In fall, the extension suggests cutting back the long runners and storing the cuttings in a glass jar in the fridge, where they keep for several weeks.
Other sources vary on how well oregano handles cold. Illinois Extension says oregano is hardy enough for central Illinois winters but can often use some additional mulch for strong spring growth, and it advises harvesting selectively in late fall. Wikipedia says the plant is a perennial but is usually grown as an annual in colder climates because it often does not survive winter.
Oregon State closes with a caution that covers all 5 herbs: each suits container gardening, but overwintering success in containers varies compared with plants grown in the ground. Illinois offers rough timing for one region: the median first frost in central Illinois falls between Oct. 11 and 17, the first hard freeze, below 28 degrees F, usually comes around Nov. 1, and the first snow typically arrives between Nov. 30 and Dec. 5.
This article was produced with AI assistance and edited for accuracy against the sources linked above.
Image: Christian Ferrer – CC BY 4.0/Wikimedia Commons
