ANR-1164 Growing Herbs
Growing Herbs
ANR-1164 Reprinted January 2006. Kerry Smith, Extension Home Horticulture Associate, Auburn University, and Wendy Ulrich, Blount County Agent Assistant.
 hether you pronounce it 'erbs or herbs, this group of plants has historically been one of the most popular to grow and has recently experienced a surge in popularity in the home garden and landscape. Why not? Herbs are among the easiest plants to grow!
Throughout time, many cultures have grown herbs primarily for their culinary and medicinal uses. Today, herbs are often classified according to their use as either culinary, medicinal, aromatic, ornamental, or household/industrial. In addition to the utilitarian uses, herbs make interesting and beautiful landscape
plants, whether they are used formally in an herb garden or informally mixed into gardens with vegetables or added to a mixed border of annuals, perennials, shrubs, and trees. Herb flowers and foliage provide a beautiful palette of color and variation in texture and form. Herbs add an element of excitement to landscaping that no other group of plants do—they evoke the senses of taste, smell, and touch.
As a group of plants, herbs can be difficult to define. From a botanical definition, an herb is herbaceous—that is, it does not form woody tissue. Most gardeners, however, take a broader view of plants grown as herbs and include plants that have roots, stems, leaves, flowers, or fruits valued for their culinary, medicinal, aromatic, household, or ornamental uses. This definition encompasses plants that have woody stems, such as cultivated varieties (cultivars) of rosemary, thyme, and lavender, as well as some shrubs, trees, and vines. Thousands of herb plants are available on the market today, some of which
have many cultivars.
Basic Herb Culture
Determining Where to Plant Herbs
Herbs are among the easiest plants to grow when given the appropriate environment. Gardeners should
choose a planting site where herbs will thrive rather than just survive. Herbs are adaptable to a wide range of soil and growing conditions; however, many do not grow well in poorly drained soil and will quickly die in a wet site.
Herbs vary in their native origin, from the Mediterranean region to Europe and Asia; therefore, consider
the plant's native habitat when determining a planting site. Most annual and perennial herbs grow best in full sun, generally 6 to 8 hours a day (see Table 2 for exceptions). Herbs preferring a cooler climate than Alabama's may simply have a shorter growing season here than in other
areas. Some examples are cilantro, dill, anise, and other members of the Umbelliferae family.
There are some special challenges to growing herbs in Alabama, including the heat, humidity, and heavy clay soils. If you want to grow herbs that don't grow well in our long, hot days, provide plants with partial or filtered afternoon shade. Space herb plants far enough apart so they get good air circulation and light.
Crowded plants do not dry quickly and may develop disease problems. Plants particularly susceptible are gray plants with fuzzy, pubescent leaves, such as lamb's ear, artemisia, sages, and others.
Because herbs must have well-drained soil to survive, Alabama's heavy clay soils should be amended with compost, peat, or other organic amendments to improve drainage and air space for root growth. Raised beds and containers are excellent environments for drainage. Regions of the state with sandy soils grow herbs easily.
Preparing the Soil
Herbs are tolerant of many soil types but grow best in a neutral (6 to 7 pH), loamy soil amended with organic matter. Perform a soil test to determine soil pH and nutritional needs. Soil testing information and
supplies are available from your county Extension office.
Incorporate organic matter and any needed lime as you break up the soil. Adding peat moss or any type of
composted organic matter will increase soil aeration and aid drainage. After thoroughly incorporating
organic material, rake the soil to remove rocks, weeds, or plant debris.
Planting Herbs
Direct Seeding
Some herbs benefit from being directly seeded into prepared garden soil. Members of the Umbelliferae
family (dill, cilantro/coriander, chervil, parsley, fennel, and anise) readily reseed themselves each year. Most perennial herbs, if directseeded, grow slowly at first. In Alabama, perennials grow best when planted in the garden as transplants during the fall. This allows the plants to establish roots before putting on new vegetative growth the next year.
When direct-seeding, sow seeds in garden furrows late March to early April or after the chance of frost has passed. Cover the seeds lightly with a shallow sprinkling of soil, or, as a rule of thumb, cover them no deeper than twice the seed diameter. Firmly tamp the soil for good seed-tosoil contact, and water using a fine mist or spray to avoid washing the seeds away. As the seedlings germinate and develop their true seed leaves, thin the plants to approximately 1 to 2 inches to avoid spindly plants that crowd one another.
Transplanting
You may want to start seeds that are expensive or have a long germination period in a greenhouse or a controlled environment indoors. Plant the seeds in mid- to late winter. Start the herbs in small containers such as peat pots, jiffy peat pellets, cell packs, or other containers designed for growing transplants. You can also use Styrofoam or cardboard cups or containers, but be sure to punch holes in the bottoms for
drainage. Start by selecting a sterile, soilless growing medium of peat mixed with perlite or vermiculite. Make sure it is well drained to reduce the chances of seedling disease problems yet able to hold
needed moisture. Make sure the seeds and seedlings get adequate light, either artificial or window
light (but not full sun), and a controlled temperature between 60 and 70 degrees F. Label the plants with their name and the planting date. Water the containers, and allow them to drain completely.
After the chance of frost has passed but before setting the plants out, harden off the young transplants by reducing the amounts of water and fertilizer. Move the transplants outside to a shaded area, and each
day, gradually expose them to a little more sunlight, wind, and normal outdoor conditions. When the plants
seem strong and healthy enough, transplant them to prepared beds or a garden. Tamp the soil and water the plants, making sure the plants are not deeper than in their original containers.
Other Methods of Propagating Herbs
If plant parts are obtained during the right season, they will respond well to and can be produced faster through propagation. These methods include dividing, taking stem and root cuttings, and layering.
Dividing
Herbs that are easily divided include chives, oregano, yarrow, mints, and other plants that spread by clumps or stolons (runners). During the winter months, when the plants begin dormancy, use a trowel or knife to pull apart or separate the plants into clumps. Before using this method of propagation, however, remember that some herbs that spread by stolons can be invasive if they are not grown in a contained area.
Taking Stem Cuttings
Some herbs can be propagated from stem cuttings at several times during the year (Table 1). In the spring,
take softwood cuttings by pruning back new shoot growth after it hardens slightly, and in the summer,
take them after flowering when the new flush of summer growth has strengthened. For softwood cuttings, use a sharp knife or pruning shears, and take 2- to 4- inch cuttings, removing a few leaves from the
bottom third of the stem. Take 4- to 6-inch semihardwood cuttings in the fall, and take 6- to 12-inch
hardwood cuttings during the dormant season or in midwinter.
Place cuttings in a propagation bed under mist or in a container that can be covered and treated like a greenhouse environment. Use a soilless peat and perlite or vermiculite medium that contains a wetting agent or is well moistened. Dip the ends of the stems into a rooting powder. Insert about one-third of this bottom end into the potting medium. Firm the medium gently to ensure contact. Make sure the cuttings are shaded and misted each day to avoid wilting until roots form.
Table 1. Herbs That Can Be Propagated from Stem Cuttings
| Rosemary |
Myrtle |
Oregano |
| Salvia varieties |
Lemon verbena |
Wormwood |
| Curry |
Scented Geraniums |
Santolina |
| Thyme varieties |
Marjoram |
French tarragon |
Taking Root Cuttings
Though this method is used less often, some herbs can be propagated from root cuttings. Cut two or three root sections of a horseradish or comfrey plant, and plant them into potting medium. That's all you need!
Layering
Herbs respond well to layering, which occurs naturally for some plants. To layer plants, place a rock on top of a branch, or dig a trench and mound the soil over part of a branch. Roots will form at the nodes having soil contact. This part can then be removed from the parent plant.
Buying Herb Plants
If you don't want to propagate your own herb plants, you can, of course, buy them. Even the most inexperienced gardener can learn how to select healthy herb plants. Follow these tips when selecting an herb plant.
- Choose a good, sturdy plant that is not in the seedling stage but is well developed for the size container in which it is growing.
- Take the plant out of its container and inspect its roots. They should be white and should fill the container but not be a solid mass, or root bound. Root bound plants have a difficult time recovering from this stunted period.
- Check the leaves for any insects or disease problems.
Remember, the best plant is not always the largest one.
Caring for and Maintaining Herbs
Fertilizing
Herbs require minimal fertilization. In fact, herbs often suffer from overwatering and overfertilizing rather than from not enough. If your soil test recommends that a complete fertilizer, such as 10-10-10, be broadcast at planting, that may be enough nitrogen for the entire season.
Slow-release fertilizers can be used to help herbs establish. Many gardeners prefer to only use organic
fertilizers such as manures. Organic fertilizers generally break down slower in the soil and have other benefits that help improve plant growth and soil.
Watering
Water herbs during dry periods. It is better to irrigate to maintain soil moisture to a depth of 6 to 8 inches than to lightly sprinkle the soil surface every day. Some herbs wilt faster than others and may require more frequent watering, particularly during hot weather and if grown in containers.
Controlling Weeds
Try to remove as many perennial weeds as possible before planting a garden. Weeds compete for nutrients and water and in some cases can harbor harmful diseases and insects. Cover newly prepared garden soil with a layer of mulch to prevent weed seeds from germinating in the sunlight. Mulches also conserve soil moisture, keep plant roots cool during summer and protect plants during winter. A layer of organic mulch, such as pine straw or leaves, will be attractive as well as functional.
Pruning
Pruning naturally stimulates plant growth. Pruning herbs can be as simple as pinching back growing tips
to encourage branching; removing, or deadheading, spent flowers; or harvesting a major portion of plant
growth for drying and preserving. Pinching back herbs throughout the growing season is the best way to
maintain healthy, vigorous, attractive plants.
Prune branches just above a leaf node or above another branch where you want to force new growth to occur. It is important to deadhead herbs to keep plants growing and to encourage more flowering.
Harvesting Herbs
The best time to harvest herbs is when you are ready to use them. Using clipped sprigs from plants throughout the growing season is the easiest way to maintain herbs, so harvest only as much as you need each time. If harvesting large amounts, follow these guidelines.
- Keep in mind an herb's growth habit to determine when and how much of the plant to prune back. With some annuals, the entire plant is often harvested to the ground at the end of the growing season. Examples of such annuals include dill, coriander (for seeds), cilantro (for leaves), and basils. Biennial herbs, including parsley, angelica, and caraway, produce leaves during the first year and flowers and seeds the second year. Perennials can have as much as half of their foliage pruned back at one time except during extreme heat or drought when the plant is under stress.
- Do not prune herbs drastically in the fall when the plants are preparing for dormancy. Pruning during the fall can stimulate plant growth, resulting in damage from freezing weather.
- Harvest herbs in the morning hours after the dew has dried but before the heat of the sun wilts the plant. Volatile plant oils are at their peak in the cooler, morning hours.
For information about drying and storing herbs, see Extension publication HE-0605, "Drying
Herbs".
References
Armitage, A. M. (1997). Herbaceous perennial plants: A treatise on their identification, culture, and garden attributes (2nd edition). Champaign, IL: Stipes Publishing, L.L.C.
Hill, M., and Barclay, G., (1997). Southern herb gardening. Fredericksburg, TX: Shearer Publishing.
Hopkinson, P., Miske, D., Parsons, J., and Shimuzu, H. (1994). Herb gardening. New York: Pantheon Books.
Kowalchik, C., and Hylton, W. H., (ed.) (1998). Rodale's illustrated encyclopedia of herbs. Emmaus, PA: Rodale Press, Inc.
Table 2. Selected Herbs for Alabama
Common Name
Scientific Name |
Family |
Plant Type |
Height |
Spacing |
Form |
Light Req. |
Bloom Time |
Foliage Color |
Flower Color |
Uses |
Maintenance |
Notes |
Aloe
Aloe spp. |
Liliaceae |
tender perennial |
up to 2' |
container |
rosette |
full sun to light shade |
mid-
summer |
green |
yellow to orange to red |
medicinal |
Cut out dead or yellowed leaves. |
Grow in a container. |
Basil
Ocimum basilicum |
Labiatae |
tender annual |
2' to 3' |
2' to 3' |
small bush, erect branching |
full sun |
July and August |
varies |
white |
culinary, aesthetic |
Cut off flower stalks for better foliage. |
Many cultivars are available. |
Bay
Laurus nobilus |
Lauraceae |
tender perennial |
up to 10' |
6' or more |
tree |
full sun to part shade |
spring |
dark green |
insignificant |
culinary |
Remove leaves from food before eating. |
May reach 15' to 30' in South. |
Beebalm
Monarda didyma |
Labiatae |
perennial |
3' to 4' |
3' to 4' |
bush, spreading (can be invasive) |
full sun to part shade |
July to August |
dark green |
pink, red, white |
ornamental, culinary |
Divide as necessary. |
Flowers are edible. |
Calendula (pot marigold)
Calendula officinalis |
Compositae |
hardy annual |
18" |
1' to 2' |
stem with basal rosette |
full sun |
fall to spring |
green |
pale yellow to deep orange |
ornamental, culinary |
Deadhead for better flowering. |
|
Catnip
Nepeta cataria |
Labiatae |
perennial |
1' to 3' |
3' to 4' |
spreading |
full sun to part shade |
July to September |
gray to green |
white with lavender |
cat toys, medicinal |
|
Cats may damage foliage. |
Cayenne Pepper
Capsicum annum |
Solanaceae |
tropical |
up to 2' |
container |
bush |
requires full sun |
summer |
bright green |
white with red, orange, or green fruits |
culinary, ornamental |
Keep well watered and well drained. |
Edible fruits range from mild to hot. |
Chamomile
Roman chamomile
Chamaemelum nobilis
German chamomile
Matricaria recutita |
Asteraceae |
perennial
hardy annual |
2" to 6" flowers on 1' stems
up to 2' |
6" to 12"
1' to 2' |
mat
weedy |
full sun to part shade |
summer |
bright green |
yellow and white, daisylike |
ornamental, medicinal |
Weed well. |
Take care not to overfertilize. |
Chives
Common chives
Allium schoenoprasum
| Liliaceae |
perennial |
1' to 2' |
1' |
grasslike clump |
full sun |
June |
green |
purple |
culinary |
|
Flowers are edible. |
Garlic chives
Allium tuberosum |
Lilacea |
perennial |
2' to 3' |
1' |
grasslike clump |
full sun |
June |
green |
white |
culinary |
Can be invasive |
|
Coneflower
Echinacea purpurea |
Asteraceae |
perennial |
2' to 4' |
1' to 1.5' |
stem with basal rosette |
full sun |
midsummr to frost |
dark green |
purple to pink |
ornamental, medicinal |
Deadhead old flowers for better blooming. |
'Bright Star' is a good choice; white cultivars are available. |
| Cilantro/Coriander Coriandrum sativum |
Umbelliferae |
hardy annual |
1.5' to 2.5' |
seed, thin to 4" |
erect with lacy foliage |
sun to part shade |
spring or mid to late summer |
bright green |
white or mauve |
culinary |
Weeding and mulching are necessary. |
This plant self-seeds; young leaves are cilantro; seeds are coriander. |
Costmary
Tanacetum balsamita (formerly Chrysanthemum
balsamita) |
Compositae |
perennial |
2' to 3.5' |
1' to 2' |
leggy, upright with staking |
sun to part shade |
late summer |
bright green |
daisylike, white rays |
culinary |
Prune to prevent flowering. |
Divide rhizome to propagate. |
Dill
Anethum graveolens |
Umbelliferae |
annual |
3' to 5' or less |
seed, thin to 6 to 18" |
erect with lacy foliage |
full sun |
spring to early summer |
blueish-green |
yellow umbels |
culinary |
Prune flowers for better foliage. |
Sow seed in early spring and fall. |
Fennel
Foeniculum vulgare
Florence Fennel
Foeniculum dulce |
Umbelliferae |
perennial or annual
annual |
3' to 5'
12" |
2' to 3'
seed, thin to 6-8" |
upright with feathery foliage bulbous stem, feathery foliage |
full sun |
June to August |
green, bronze or purple |
compound yellow umbels |
culinary |
"Bulb" may be harvested for salads, etc. |
This is the preferred host of swallowtail butterflies. |
Foxglove
Digitalis purpurea |
Scrophu-
lariaceae |
biennial |
3' to 4' |
seed indoors, transplant to 1' |
upright stem with staking, basal rosette |
part shade |
spring to late summer |
deep green |
purple with spots of white and purple |
ornamental |
This plant needs lots of water to bloom best. |
Toxic! This is the source of digitalis heart medicine. |
Germander
Teucrium chamaedrys |
Labiatae |
evergreen perennial |
1' |
2' |
bushy and clump forming |
full sun to light shade |
summer |
bright green |
pink and purple |
ornamental |
Keep moist; avoid hedge pruning. |
'Variegatum' has ivory variegation. |
Hyssop
Hyssopus officinalis |
Labiatae |
evergreen perennial |
2' to 3' |
1.5' |
upright and shrubby |
light shade |
June to August |
green |
blue spikes |
ornamental, medicinal |
Prune, deadhead for best blooms. |
This is a good bee and butterfly plant. |
Lavender
English lavender
Lavandula angustifolia
Spanish lavender
Lavandula stoechas |
Labiatae |
evergreen perennial |
2' to 2.5'
1' to 2' |
3'
3' |
shrubby
shrubby |
full sun |
June to September |
grayish green |
purple |
ornamental, medicinal |
Watch for rot if plant gets too wet.
Prune hard in July for rebloom. |
This plant is highly prized for its essential oil.
This is the best species for Southern hardiness. |
Lavender Cotton
Grey lavender cotton
Santolina chamaecyparissus
Green lavender cotton
Santolina virens |
Compositae |
evergreen perennial |
1' to 2' |
2' to 4' |
shrubby |
full sun |
June and July |
gray
green |
bright yellow |
ornamental |
Plant in light, dry soil. |
Harvest before flowering for best aroma. |
Lemon Balm
Melissa officinalis |
Labiatae |
perennial |
2' to 3' |
3' to 4' |
bushy, spreading |
full sun to shade |
July to September |
green to coppery |
white or yellow |
culinary, ornamental |
Divide every 3 to 4 years. |
Use this for its lemony taste. |
Lemon Verbena
Aloysia triphylla |
Verbenaceae |
tropical perennial |
up to 6' |
3' to 4' |
shrubby and leggy |
full sun |
late summer to fall |
lime green |
white |
ornamental, culinary |
Overwinter this herb in a container inside. |
This herb is susceptible to spider mites and whiteflies. |
Marjoram
Origanum majorana |
Labiatae |
tender perennial |
up to 3' |
4' |
rounded, spreading |
full sun |
August to September |
dark grayish green |
tiny, pink or white |
culinary, ornamental |
Pinch back before flowering to keep shape. |
This herb keeps well dried. |
Marsh Mallow
Althaea officinalis |
Malvaceae |
perennial |
4' to 5' |
3'-4' |
erect with spreading branches |
shade |
July to September |
grayish green |
pink or white |
ornamental |
Divide as needed in the spring. |
Moist soil is a must! |
Mint
Mentha spp. |
Labiatae |
perennial |
1' to 2' |
2' |
low, bushy, spreading |
full sun to part shade |
July and August |
bright green |
purple, pink, or white |
culinary, ornamental, medicinal |
Grow this herb in a container to control root growth. |
Mints are very invasive and will take over if allowed. |
Nasturtium
Tropaeolum majus |
Tropaeolaceae |
annual |
1' to 2.5' (or 6' vine) |
seed to 6" to 9" |
bushy to viney |
full sun to part shade |
February to June |
dark grayish green |
red, orange, or yellow |
ornamental, culinary |
Sun is necessary for plant to bloom. |
Flowers and leaves are edible, beautiful in salads. |
Greek Oregano
Origanum heracleoticum |
Labiatae |
perennial |
1' to 2' |
2' |
bushy, spreading |
full sun |
July to September |
green |
white |
culinary |
Prune in order to maintain shape. |
Variegated and ornamental varieties. |
Parsley
Petroselinum crispum |
Umbelliferae |
biennial |
1' to 1.5' |
1' |
rosette |
full sun |
May to September |
dark green |
greenish yellow |
culinary |
Prune old, outside leaves or harvest these first. |
Replace every year to avoid bolting. |
Rosemary
Rosmarinus officinalis |
Labiatae |
evergreen perennial |
4' to 6' |
3' to 4' |
upright and shrubby |
full sun |
early summer |
dark green |
lilac to blue |
culinary, medicinal |
Prune to desired shape. Try a hedge or topiary. |
This herb will not transplant well. |
Rue
Ruta graveolens |
Rutaceae |
evergreen perennial |
1' to 3' |
18" |
bushy |
full sun |
June to August |
bluish gray |
yellow |
ornamental |
Keep soil well drained. |
Rue causes contact dermatitis in some people. |
Sage
Garden sage
Salvia officinalis
Mealy cup sage
Salvia farinacea
Mexican bush sage
Salvia leucantha
Pineapple sage
Salvia elegans
Russian sage
Perovskia atriplicifolia |
Labiatae |
perennial |
1' to 3'
up to 4'
4' to 5'
3' to 4'
3' to 4' |
2'
2' to 3'
3'
3' to 4'
2' to 3' |
bushy
stemy
bushy
bushy
bushy |
full sun to part shade |
June
June to September
August to September
August to October
June to August |
cultivar dependent
grayish green
dark green
green
grayish green |
white to purple
light blue
purple
red
lilac |
culinary
ornamental
ornamental
culinary, ornamental
ornamental |
Keep soil dry.
Prune to keep good shape.
Prune in June so stalks can hold flowers upright. |
'Berggarten' is a good choice.
Butterflies and hummingbirds love this plant!
This is a gorgeous plant worth growing! |
Texas Tarragon or
Sweet-Scented Marigold
Tagetes lucida |
Asteraceae |
perennial |
3' to 4' |
2' to 3' |
erect and bushy |
full sun |
fall (into frost) |
bright green |
yellow |
culinary |
Prune if desired. |
Foliage has a terrific anise flavor. |
Thyme
Common thyme
Thymus vulgaris
Creeping thyme or mother-of-thyme
Thymus praecox
Lemon thyme
Thymus x citriodorus
Woolly thyme
Thymus pseudolanuginosus |
Labiatae |
evergreen perennial |
1'
2" to 3"
4" to 12"
2" |
1'
6" to 8"
1'
6" to 10" |
upright and shrubby
mat
upright and shrubby
mat |
full sun |
June to July |
green
dark green
golden edged
grayish green |
rose
purple
lilac
pink |
culinary |
Divide or replace when center dies. Frequent pruning will extend plant life. |
Silver foliage may rot if overwatered.
"Woolly" refers to the herb's fuzzy leaves. |
Wormwood
Artemisia spp. |
Compositae |
perennial |
3' to 4' |
2' to 3' |
bushy |
full sun |
July to August |
silvery green |
greenish yellow |
ornamental |
Silver varieties will rot if too wet. |
A. x 'Powis Castle' and x 'Silver King' are great choices. |
Yarrow
Achillea millefolium |
Asteraceae |
perennial |
6" to 10" |
3' to 4' |
spreading rosette |
full sun |
June to September |
grayish green |
white, pink, yellow |
ornamental, medicinal |
Divide after 3 to 5 years. |
Many cultivars are available. |
For more information, contact your county Extension office. Visit http://www.aces.edu/counties or look in your telephone directory under your county's name to find contact information.
Issued in furtherance of Cooperative Extension work in agriculture and
home economics, Acts of May 8 and June 30, 1914, and other related
acts, in cooperation with the U.S. Department of Agriculture. The Alabama
Cooperative Extension System (Alabama A&M University and Auburn
University) offers educational programs, materials, and equal
opportunity employment to all people without regard to race, color,
national origin, religion, sex, age, veteran status, or disability.
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