Growing and using herbs
February 1, 2011 - Author: Gretchen Voyle, Michigan State University Extension
People around the world have used herbs for centuries in cosmetics, fragrances, medicines, dyes and cooking. Today, herbs are more popular than ever for cooking.
The part of the plant that is being used defines it an herb or a spice. For example, Chinese parsley is an herb called cilantro when its green leaves are used for flavorings. When the seeds are used, it is called coriander and it is a spice.
Herbs are defined as annual or perennial plants whose leaves, stems and flowers and sometimes seeds and seed heads are used for flavor or fragrance.
Spices are usually roots, bark, fruits, berries and sometimes seeds of plants (including trees) that often grow in tropical climates.
Most herbs will be either perennial or annual in growth:
- Perennial herbs will die to the ground at the end of each growing season and return next year from the roots.
- Annual herbs will die with the first frost. New plants or seeds need to be put in the garden each spring.
Herbs for the garden can be purchased as seeds or plants from nurseries or plant catalogs. It will take longer for seeds to produce edible parts than it will for plants. Gardeners have the option of growing an herb garden or mixing the herbs in with plantings of vegetables or flowers. A small garden outside the kitchen door is convenient to quick seasoning excursions. It is also possible to grow some herbs on a sunny windowsill in your house over the winter.
How to plant herbs
Generally, herbs can be grown in sunny, well-drained areas in the garden. Wet or heavy soil is not suitable. These areas need to receive eight or more hours of full sunlight a day. Some herbs may grow in partially shaded areas but will not have the flavor of full-sun locations. Avoid windswept areas.
Get a soil test to determine nutrients and soil pH. A soil pH of 6.5 would be ideal. Many herbs do not need to be fertilized. Many will do well with just compost. Some herbs benefit from winter protection, which means covering them with straw or other mulch.
Most are relatively disease and insect free. Be very careful about the use of pesticides (insecticides or fungicides) on herbs that are intended to be eaten or used for beverages. Most pesticides are not suitable for plants that are to be consumed.
What to plant
This a partial list of culinary or beverage herbs for Michigan gardens. Many others are available as plants or seeds.
Perennial herbs that can be grown in Michigan:
- Bergamot - The “Earl Grey” tea flavor; used in dry tea mixes
- Chamomile - sweet apple-scented leaves; usually grown as an annual
- Chives - Mild onion taste; use uncooked
- Garlic chives - mild garlic flavor; use uncooked
- French tarragon* - peppery scent and anise-like flavor
- Garlic - plant in the fall for next year’s crop; may be strongly flavored and small
- Lavender - ‘Hidcote’ and ‘Munsted’ relatively hardy; prune in spring
- Lemon balm - dried lemony leaves used in teas, self-seeds prolifically
- Oregano* - bold, spaghetti sauce or pizza sauce flavor
- Peppermint - leaves and oil extracts used; may be invasive
- Sage - use fresh and dried leaves; green sage may be hardier than variegated or flavored varieties
- Spearmint - leaves and oil used as flavoring; rampant, aggressive spreader
- Sweet cicely - sweet, licorice flavored seeds; leaves and roots
- Sweet woodruff - sweet clover scent; used to flavor drinks
- Thyme - mild lemon-clove flavor
- Winter savory - leaves have a peppery, spicy flavor
* Need winter protection (cover with straw or other mulch); often not hardy.
Some perennial herbs become invasive; spearmint and many mints fall into that category. If the plants become invasive, they can be surrounded with a 10 to 12 inch strip of edging buried into the soil. Allow about an inch or more to protrude above ground. This will prevent the spread of roots under and over.
Annual herbs that can be grown under Michigan conditions:
- Anise - licorice like flavor
- Basil - warm, somewhat spicy flavor; used in many pesto recipes
- Chervil - parsley/anise flavor
- Cilantro - leaves give a fresh, clean taste to dishes
- Coriander - seeds have a mild, lemony taste
- Dill - fine, fern-like leaves used fresh or dry, flavor of dill pickles
- Fennel - mild licorice flavor; seeds, leaves, stems and bulb edible
- Marjoram - mild,oregano-like flavor
- Rosemary - very bold flavor; for best results, use fresh leaves in foods
- Summer savory - minty thyme flavor
Two are classified as biennial herbs which will live for two years. The first year, they produce some leaves and the next year, they grow to maturity. (1) Parsley, flat leaf or Italian, is best for culinary uses and is semi-hardy; and (2) Caraway, the flavor of rye bread; has seeds, leaves and roots that are used.
Many herbs have been historically used as medicines. This carries a risk today because of possible drug interactions with prescription medicines the person may be taking. Also, it is not possible to gauge the strength of herbs or spices so this makes dosing difficult.