It's the end of the summer. In a month or less it will be time to look out for a frost. But that doesn't have to mean the end of your herb garden.
A number of flavorful and aromatic herbs have a good chance of surviving a Chicago winter.
Some culinary herbs, such as basil, dill and cilantro, are annuals — evolved to complete their life cycle, from seed through flower to seed, in a single year. For those plants, the end of summer is truly the end.
Others evolved to be perennial, with a root system that lives for years. But it's always tricky to talk about "perennials" in a Northern climate like Chicago's. Some plants that are perennial in milder climates, such as rosemary, will be killed by frost and the swings of winter weather here. Others, made of sterner stuff, will soldier through.
For most herbs, now is the time to make your last harvest.
You can have an herb-cooking orgy, like Father Dominic Garramone, a Benedictine monk who grows vegetables and a variety of herbs and writes cookbooks in addition to teaching religion and drama at St. Bede Academy in Peru, Ill. (st-bede.com).
"Since most of my herbs are Italian herbs, I store them in the form of pizza sauce," he says.
Or you can dry herbs. Bunches of herbs hung from the ceiling in the kitchen may be decorative, but they are more likely to fade and gather dust than be used for cooking, says Liz Fiorenza, owner of Wind Ridge Herb Farm in Caledonia, near Rockford (windridgeherbfarm.com). The farm grows about 400 varieties of herbs and plants that feed bees and other pollinating insects.
A better drying method is to gather all the stems of an herb into a bunch and place them in a paper bag, punched with holes to allow air circulation. Label the bags and put them out of direct sunlight but where air circulates freely. In a couple of weeks the leaves will be dry, and you can strip them from the stems and store them in glass jars inside a cabinet or pantry where sun won't fade them.
Those herbs that are both perennial and hardy will likely resprout in spring, if they are planted in well-drained soil so the spring thaw and rains don't cause their roots to rot in the damp.
They aren't likely to make it in containers, though: The roots are too exposed to winter's bitter cold and drying winds. Either sink the container in the ground for protection, move it into an unheated garage over the winter or transplant the hardy herbs to a garden bed.
Here are some herbs that are likely survivors in northern Illinois:
Chives: Perhaps the herb most likely to succeed, chives (Allium schoenoprasum) and garlic chives (A. tuberosum) are members of the onion family. Their grasslike stems return from underground bulbs year after year, and if they have a cover of snow they often stay green and usable well into winter.
Sage: Both common garden sage (Salvia officinalis) and the purple variety (S. officinalis "Purpurascens") are strong survivors. Many gardeners are able to harvest fresh sage leaves for Thanksgiving stuffing. Herb grower Father Dominic Garramone especially likes a variety of sage called "Berggarten," which survives winters but grows only to a manageable size with tender stems.
Thyme: Many kinds reliably come back, says Liz Fiorenza of Wind Ridge Herb Farm, including common English thyme (Thymus vulgaris and its varieties) and lemon, lime and orange thyme (varieties of T. citriodorus). The decorative woolly thyme and silver thyme are not as hardy. "It depends on the winter," she says. "In a mild winter it might survive."
Parsley: There's a curveball here: Parsley (Petroselinum crispum) is a biennial, a plant with a two-year life cycle. The flat-leaf Italian parsley may well survive the winter, but in the second year the leaves will be skinny and the flavor poor as the plant works on flowering and making seeds. So it's best to grow parsley as an annual, starting with new plants or seeds each year.
Tarragon: Fiorenza finds that French tarragon (Artemisia dracunculus) overwinters well and is one of the first herbs to resprout in spring.
Oregano: Greek oregano (Origanum vulgare hirtum) is more likely to overwinter successfully than Italian oregano (Origanum x majoricum) or the closely related sweet marjoram (O. majorana).
Lavender: Native to the south of France, lavender can be tricky. "I find it can come back well if it's rather protected and it has that good drainage," Garramone says. He recommends soil that is "almost gravelly." In a wet winter, you may lose lavender anyway, Fiorenza says. But she has had good luck with English lavender species (Lavandula angustifolia), especially the variety "Munstead."
Mint: Most plants in the mint family — easily recognized by their four-sided stems — are pretty hardy. Spearmint (Mentha spicata) is so hardy and robust that it is often a nuisance. Chocolate mint (varieties of M. x piperita) and citrus mints (Mentha x piperita f. citrata) also tend to come back well for Fiorenza. But she finds that peppermint, pineapple mint and variegated varieties are too tender.