Growing, Harvesting, and Drying Herbs

Care and How-To

Herbs, botanically, are nonwoody annuals, biennials, or perennial plants that die back to the ground each year. They are plants valued for their flavor, fragrance, and medicinal uses. In the culinary sense,  herbs differ from spices. Herbs generally are leaves of low-growing herbaceous plants native to temperate areas. Spices are primarily derived from bark, flower buds, fruit, or roots of perennial, tropical plants.

herbs in containers
When space is limited, herbs, like this mint, thyme, and rosemary, are great for containers.  

Herbs are an enjoyable group of plants to grow. They require little space and care. Herbs have few insect or disease problems and generally require only moderate soil fertility levels. They can be grown easily in an apartment-sized plot, among flowers, as part of the vegetable garden, or in containers on a patio or windowsill.

Culinary herbs are often important ingredients in savory and sweet recipes. Freshly harvested herbs have distinct flavors and aromatic qualities that often exceed those of their commercially obtained counterparts—whether fresh or dried.

Because of their distinctive and pungent flavors, herbs are needed only in small quantities to flavor foods.

Usually, three or four plants of most herbs will provide sufficient seasoning for the average family.


Growing Conditions  |  Propagation  |  Summer Care  |  Harvesting  |  Drying  |  Storage  |  Other Preservation Methods  |  Information for Specific Herbs  |  FAQs  |  More Information


Growing Conditions

Annual herbs can be grown in rows in the vegetable garden; however, perennial herbs should be planted where they will not be disturbed. Establishing a separate herb garden near the house helps make herbs easily accessible for care and harvesting, and allows perennial herbs to grow year to year without being disturbed. Many herbs can be grown as part of the landscape in perennial flower borders or mixed annual containers.  

Although most herbs will grow in partial shade, they do better if they receive at least 4 to 6 hours of sunlight a day. Herbs will grow well under a wide range of soil conditions, with the exception of extremely wet, poorly drained soils. Wet soils often lead to poor growth, root rot, and untimely death.

In general, herbs do better in soils of low to medium fertility, so additional fertilizer applications usually are not needed.  Highly fertile soils tend to produce lots of foliage that has little flavor.


Basil
Basil (Ocimum basilicum)

Propagation

Most herbs, particularly annuals and biennials, can be grown  from seed. The time required for germination varies from approximately 12 to 30 days. Seed can be sown directly outdoors or started indoors and the young plants transplanted later. This method produces usable plants earlier. Learn more about starting herbs from seed in this article: Guide to Starting Seed Indoors

Perennial herbs are propagated by cuttings or division. Divide established plants every three or four years in the early spring.  Carefully dig up the clumps and cut into sections with a sharp knife. Learn more about dividing perennials in this article: Dividing Perennials in the Spring

Four to six-inch-long stem cuttings can be taken in the summer from garden plants and rooted in perlite or sand.  Once adequate roots have formed, they can be planted in the garden.   The propagation of perennial herbs by cuttings looks much like propagating annual herbs by cuttings.  Learn more about taking cuttings in this article: How to Propagate Annuals from Cuttings

Seeds and plants of various herbs can be obtained from local garden centers or online sources The seed of the more common herbs, such as dill, basil, and parsley, are usually available from local seed dealers, while less common herb seeds may need to be purchased from companies specializing in herbs.


Sage
Garden Sage (Salvia officinalis)

Summer Care

Herbs require some attention throughout the growing season. Weed control and adequate moisture are two important cultural necessities. When rainfall is less than 1 inch per week, provide additional moisture.

Mulch can be used to control weeds and retain soil moisture. A few recommended mulches include bark chips, shredded bark, compost, coco hulls, or dried grass clippings.

Many annual herbs grown for leaves benefit from removing the flower buds. This promotes additional foliage growth, improves appearance, and allows for better flavor in some species.

Herbs that spread rapidly, such as tarragon and mint, can be controlled by planting them in a large container filled with potting soil with several drain holes. Sink the pot into the soil with an inch of the rim above the ground. This can prevent roots from spreading.


Types of Basil
Various types of Basil (Ocimum basilicum)

Harvesting

Harvest time is determined by the growing conditions of the herb, rather than by a specific date or month. Most herbs are ready to be harvested just as the flower buds first appear but before they are fully open. The leaves contain the maximum amount of volatile oils at this stage of growth, giving the greatest flavor and fragrance to the finished product.

It is best to harvest herbs early in the morning, just after the dew has evaporated and before the sun is hot.

Annuals

Leafy annual herbs can be cut back quite severely when they are harvested. Use a sharp knife or pruning shears and cut just above a leaf or pair of leaves, with approximately 4 to 6 inches of the stem remaining for later growth.

If an annual herb is grown for its seed (such as dill), do not cut it back or use the leaves. Allow the plants to mature fully and form their seeds before harvesting them. Collect the seed heads when they are turning brown. Cut them from the plants and place them in a paper bag for carrying and drying. After the seeds drop off into the bag, spread them out on a tray made of very fine wire mesh or cheesecloth until they are thoroughly dry.

Perennials

Do not cut back leafy perennial herbs as heavily as annual herbs. Remove only about one-third of the top growth at a time and, in some cases, only the leafy tips. Use caution when harvesting to carefully prune the perennial herbs so that more growth is produced and a compact growth habit is maintained. Most perennial herbs, such as tarragon and oregano, will be ready to harvest just before or during the early part of July in Iowa. A second harvest in September also can be made.


rosemary in container with lantana
Rosemary (Salvia rosmarinus, syn: Rosemarinus officinalis) in a container with lantana.

Thyme
Thyme (Thymus vulgaris)

Drying

When drying herbs, regardless of the method chosen, the herbs should be fresh and clean. To clean them, wash the stems in cold running water and then drain them thoroughly on paper towels.

Air

The easiest way to dry herbs is to allow the leaves or entire stems to air dry at room temperature.

To dry whole branches or stems, first wash and dry them as described above. Gather five to eight stems together and tie them into a small bundle. Hang them in a dark, warm place (70° to 80°F). It will take from two to four weeks for herbs to completely dry, depending upon temperature and humidity.

Tray drying is the method used most often for short-stemmed herbs or for individual herb leaves. An old window screen or smaller drying trays fashioned from two-by-two lumber and screening will work well. By placing spacers at the bottom of each tray, the trays can be stacked to allow good air circulation and to take up little space. Keep the trays in a warm, dark place until the herbs are thoroughly dry.

Silica Sand

Silica sand is often used to preserve flowers for crafting. Silica sand, available from local building supply dealers or craft stores, draws moisture out of plant tissues while maintaining their original shape. Any type of container can be used—old shoe boxes, baking pans, boxes, and the like—but they should be big enough so that the plant materials can be completely covered with sand.

First, wash and dry the leaves as described above. Place a shallow layer of silica sand in the bottom of the container; then arrange the herbs on top so that they do not overlap. Then cover them completely with more silica sand. Place the container in a warm room. It will take from 2 to 4 weeks for the herbs to dry thoroughly. When they are dry, remove them from the container, shake off all the sand, and store them in glass jars. Since it is sometimes difficult to shake off all of the sand, herbs preserved in this manner are not normally used for culinary purposes.

Fennel
Fennel (Foeniculum vulgare)

Heat

An ordinary oven, dehydrator, or microwave can be used for faster drying of herbs. Drying with heat is faster, but if the herbs are desiccated too quickly at too high a temperature, much of the flavor, oils, and color will be lost. To oven dry, place the leaves or stems on a cookie sheet or shallow pan and warm at no more than 180°F for 3 to 4 hours with the oven door open.  When using a dehydrator, follow the instructions that come with the appliance.   To dry your herbs in a microwave oven, place the clean stems or leaves on a paper plate or towel and set the control to high for 1 to 3 minutes. Turn the stems over or mix the leaves every 30 seconds.


Storage

After the herbs are completely dried, store them in airtight jars in a cool, dry place. If entire stems were dried, remove the leaves and crush or crumble them before placing them in jars. Remember that it is important to have the herbs completely dry; otherwise they may mold. Keep the jars away from light and heat since both destroy the quality of the herbs.


Other Preservation Methods

Flat-leaf Parsley
Flat-leaf Parsley (Petroselinum crispum)

Freezing

Many herbs can be successfully frozen, and they retain their freshness after being thawed. To freeze herbs, first harvest and wash them thoroughly, then blanch them in boiling water for a minute or two. Cool them quickly in ice water, drain them thoroughly, and put them in packages. Label each package and place in the freezer.

Herbs, such as parsley, chives, and basil, can be puréed with a small amount of water in a blender, then poured into ice cube trays. When the cubes are thoroughly frozen, they can be stored in labeled plastic bags and later used to flavor soups and sauces as needed.

Herb Vinegars and Oils

Herb vinegars and oils are easy to make. Depending on the kinds and flavors you want, place the herb(s) in a jar or bottle, and cover them with white vinegar or olive oil. Secure with a tight lid and store in a cool, dry place. After steeping for 4 to 6 weeks, pour off into smaller bottles and cap. Flavored vinegars and oils should be used within 4 to 6 months.

Herb Butter

Soften one-quarter pound of butter at room temperature. Add about 4 tablespoons of fresh or dried herb leaves and a dash of lemon juice. Beat with an electric blender until light and fluffy. Store in the refrigerator in a covered container.

Herb Mustard

Mix 8 tablespoons of dry mustard, 8 tablespoons of flour, 4 tablespoons of salt, and 1 teaspoon of sugar. Add enough vinegar to the mixture to make a smooth paste. Divide into four portions and into each portion mix 1 tablespoon of your favorite herb(s).

Pineapple Sage in bloom
Pineapple Sage (Salvia elegans)

Potpourri

A potpourri is a mixture of dried herbs and flower petals that preserves the aromatic fragrances of the summer months. Many different blends can be made, depending wholly upon personal preferences and the availability of ingredients.

Most potpourris start with dried rose petals and lavender flowers or leaves as a base, to which other dried herbs are added. Dried aromatic herbs often used for potpourris include sweet basil,  sweet marjoram, lemon balm, scented geranium, rosemary, thyme, and mint.

To make a potpourri, mix 4 to 6 cups of various dried petals and leaves in a large bowl. From the kitchen spice rack, add a tablespoon of whole cloves, cinnamon, or ginger. To blend the scents and to make them last, add a fixative, such as calamus root, benzoin, or orris root. Only 1 ounce of a fixative is needed per batch. Store the mixture in jars with tight-fitting lids. Shake or stir occasionally.

After 4 or 5 weeks, the potpourri mixture should be well blended and can be placed in decorative crystal canisters or other ornamental containers. To freshen a room, simply open the canister and stir up the delightful perfumes of the summer garden. Also try your potpourri mixture in sachets.


Growing, Harvesting, Preserving, and Using Specific Herbs

Herb

Scientific Name

Type

Harvesting and Preserving

Use

Notes on Growing

Anise

Pimpinella anisum

Annual

The green leaves can be cut whenever the plants are large enough. The seeds are ready to harvest when they turn brown. Wash the seeds in warm water, drain thoroughly, and allow to air dry.

The leaves can be used in salads, soups, beverages, meats, game, and poultry.

The seeds are used to flavor cakes, breads, and cookies. Leaves and seeds also add a delightful scent to sachets and potpourris.

Grows well in containers.
Sow seed directly in the garden as anise does not transplant well.

Balm, lemon

Melissa officinalis

Perennial

Fresh leaves can be picked any time. For dry or frozen leaves, harvest just before the plant flowers. Hang in bunches to dry, or place on trays.

Use in herb teas and as a garnish for iced tea. Adds a pleasant taste to lettuce or fruit salads. Primary ingredient or herb in pesto. 

Needs well-drained soils over winter.

Basil, sweet

Ocimum basilicum

Annual

For fresh use, harvest the leaves as they mature—about 6 weeks after planting. For dry use, harvest leaves just before the plant blooms can be dried or frozen.

One of the most popular herbs, used mainly with tomato and egg dishes, stews, soups, and salads, but also with many vegetable, poultry, and meat dishes.

Grows well in containers.  Remove flowers as they appear.
Sow seed indoors 4-6 weeks before transplanting.

Caraway

Carum carvi

Biennial

The seeds are harvested after they turn a gray-brown color. Scald the seeds in boiling water, then dry thoroughly.

Use the seeds in breads, cakes, cookies, potato salad, and baked fruit (apples,

for example). Also can be used in Hungarian-type dishes, coleslaw, sauerkraut, cheese spread, meat stews, and fish casseroles.

Plants do not like root disturbance and readily self-seed in the garden.
Sow seed directly in the garden as caraway does not transplant well.

Chervil

Anthriscus cerefolium

Annual

For fresh use, pick the tips of stems once a month. For dry use, harvest leaves just before the blossoms open. Dry on trays.

Use fresh leaves the same as you would parsley, such as in salads, salad dressings, soups, egg dishes, and cheese souffles.

Plant early in the growing season as it bolts readily in the warm temperatures of summer.
Sow seed directly in the garden as chervil does not transplant well.

Chives

Allium schoenoprasum;
A. tuberosum

Perennial

Leaves can be harvested any time during the growing season. Cut them off close to the ground. Can be dried or frozen

Chives add a mild onion-like flavor to dips, spreads, soups, salads, omelets, casseroles, and many kinds of vegetables.

Easily propagated through division. Deadhead to limit potential reseeding.

Coriander/Cilantro

Coriandrum sativum

Annual

The leaves (cilantro), which are used primarily fresh, can be harvested as soon as the plants are 4 to 6 inches tall. The seeds (coriander) can be harvested when the heads turn brown.

Cilantro leaves add a distinct flavor to salsa and other dishes. They smell and taste like a mixture of sage and orange and can be used in baking, poultry dressings, and French salad dressing. Much used in Chinese, Middle Eastern, and Latin American cuisine.

Easy to grow as an annual.  Readily reseeds in the garden. 
Sow seed directly in the garden as cilantro does not transplant well.

Currey

Murraya koenigii

Annual

The highly aromatic leaves are harvested any time during the growing season. 

Curry leaves are an important flavor in Indian and Asian cuisine and best used fresh in cooking vegetable dishes.  Also used to falvor meat, seafood, chutneys, coconut sauces, relishes, and marinades.  The flavor is enhanced when the leaves are fried in oil or butter. 

Plants can be grown as annuals or as tender perennials that are overwintered in containers indoors.
Propagate by stem cuttings, seed propgation is difficult and time consuming.

Dill

Anethum graveolens

Annual

The fresh leaves can be harvested as needed and used as seasoning. Seed heads should be harvested when the seeds ripen to a light brown color.

Leaves and seed heads are most commonly used in the making of dill pickles. The leaves also add a characteristic flavor to salads, cottage cheese, soups, fish dishes, omelets, sauces, and vegetable casseroles. Dill seeds are sometimes used in pastries, sauces, sauerkraut dishes, and for flavoring vinegar.

Frequently reseeds in the garden. 
Sow seed directly in the garden as dill does not transplant well.

Fennel

Foeniculum vulgare

Tender Perennial

The leaves can be harvested and used fresh.  Fennel seeds are harvested when the seed heads turn brown.  Dry in a paper bag.  Florence fennel is harvested when the bulbs are large enough.

The anise-flavored leaves and seeds of this herb are widely used in fish dishes, cheese spreads, and vegetable dishes.  The leaves and stems can be used in much the same way as celery.  Florence fennel bulbs are used in salads or roasted with other vegetables. 

Often grown as an annual in the garden.  Both green and bronze foliage types will reseed.  Bulb types require a longer growing season.
Sow seed directly in the garden as fennel does not transplant well.

Lavender

Lavandula angustifolia

Perennial

The whole flower spikes are cut just before the florets are fully open when color and fragrance are at their best.

Lavender is most often used in sachets, perfumes, and potpourris, but it also adds a floral flavor to desserts.

Select hardy cultivars like ‘Hidcote’ or ‘Munstead’.  Must be grown in well-drained soils, especially over the winter.

Lemongrass

Cymbopogon citratus

Annual

Harvest the lower leaf sections when large enough. 

Adds a lemony flavoring in Thai, Vietnamese, Laotian and Cambodian cuisine.  Use finely minced, ground, or mashed with mortar and pestle.  Fresh or dried leaves can flavor stews, soups, or teas.

The seed is difficult to find. Start new plants from transplants or rooted stalks obtained from grocery stores.

Lovage

Levisticum officinale

Perennial

Harvest young, tender leaves and use fresh. You can dry or freeze the leaves for later use.

Use the celery-flavored leaves in soups, stews, potato salads, meat, and vegetable dishes. It can also be eaten

raw like celery. Its seeds are sometimes used in salads, candies, breads, and cakes.

Plants readily reseed if not deadheaded.  Periodic cut-back will produce new leaves throughout the growing season.

Marjoram, sweet

Origanum majorana

Annual

Cut back to 1 inch above the ground just before flowering; a second crop will form for later use. Easily dried or frozen.

Use marjoram leaves with meat, poultry, vegetable dishes (especially green beans), potato salad, and egg dishes.

Works well in containers.  Grows best in sharply draining soils.
Sow seed indoors 8 weeks before transplanting.

Mint

Mentha spp.

Perennial

Aggressive spreader. Harvest before flowering and use fresh or dried. Cut off near ground level. A second cutting can be harvested later on.

Used primarily for flavoring. The leaves are often put into teas and other beverages, as well as lamb, sauces, and jellies.

Plant in a container partially sunk in the ground to prevent spreading.

Oregano

Origanum vulgare

Perennial

Harvest leaves and dry before flowering occurs. A second cutting can be harvested later on. Harvest leaves and dry before flowering occurs. A second cutting can be harvested later on.

Oregano imparts a sharper flavor than sweet marjoram. It is used to season spaghetti sauces, tomato dishes, and pizza sauce. Its flowers are attractive in summer arrangements.

Grow in well-drained soils.  Clip back periodically to promote new growth and reduce or prevent flowering (which can adversely affect the flavor).

Parsley

Petroselinum crispum

Annual

Snip young leaves just above ground level, as needed. Leaves can be dried or frozen.

Use as a garnish in soups, salads, meats, and poultry.

A biennial grown as an annual in the garden.  Flat and curly leaf types are available.
Sow seed indoors 8 weeks before transplanting.

Rosemary

Salvia rosmarinus (syn: Rosemarinus officinalis)

Tender Perennial

Harvest the young, tender stems and leaves, but avoid taking off more than one-third of the plant at one time. Small bunches of stems are often dried then the leaves are stripped, crushed, and stored in a container. 

A gourmet seasoning for meats, poultry dishes, and potatoes. Use either fresh or dried.

Can be overwintered indoors in a sunny window.
Propagate by stem cuttings as seed germination is more difficult.

Sage

Salvia officinalis

Perennial

Harvest when just starting to flower and use either fresh or dried.

A commonly used seasoning for meats, stuffings, soups, and salads.

Sage is available in green, gray, or variegated foliage types.

Sage, Pineapple

Salvia elegans

Annual

Harvest leaves or flowers any time during the growing season and use fresh.

Fresh leaves may be added to salads, fruit salads, or hot/iced teas.  Dried leaves are used in potpourris.  Flowers are added to fruit cocktails or salads.

Grows well in containers.  Bright red flowers attract hummingbirds and appear very late in the growing season.  Plants are sometimes killed by frost before flowers appear.
Sow seed indoors 6-8 weeks before transplanting.

Summer savory

Satureja hortensis

Annual

Gather young stem tips early, but when the plant begins to flower, harvest the entire plant and dry.

Used to flavor fresh garden beans, vinegars, soups, stuffings, and rice.

Grows well in containers.
Sow seed indoors 6-8 weeks before transplanting.

Tarragon, French

Artemisia dracunculus

Perennial

Harvest in June for steeping in vinegar. For drying, harvest in early to mid-July.

Often used in various sauces, such as tartar and white sauce, and for making herb vinegar.

Grow in well-drained soils.  Plants have sterile seeds and must be propagated by division or cuttings.

Thyme

Thymus vulgaris

Perennial

Cut leafy stem ends and flowers when plants are at the full-flowering stage. Use fresh, hang-dry, or freeze.

Used in combination with other herbs. Leaves can be used with meats, soups, sauces, and egg dishes.

Makes an excellent groundcover.  Many types of thyme are available.


Mint
Mint (Mentha sp.)

FAQs


More Information

Authors: 

Cynthia Haynes Professor

Dr. Haynes is a Professor of Horticulture at Iowa State University in Ames.  Her primary responsibilities are in teaching and extension.  She teaches several courses for the Department of Horticulture including Home Horticulture and Herbaceous Ornamentals.  She also has extension r...

Last Reviewed: 
January, 2023