A Guide to Growing Herbs

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Herbs, large or small, are a tasty and easy to grow addition to gardens, raised beds or containers. Many herbs are quite visually pleasing and can be grown alongside vegetables and flowers, in a dedicated herb garden or even in window boxes and containers. Herb plants are decorative as well as useful and are an inexpensive way to obtain many of your own flavorful seasonings.

Herbs growing

General Requirements

  • A well-drained site which receives at least six hours of sun each day. To improve an area with poor drainage, consider the following options:
  1. Double dig to loosen compacted subsurface soil layers.
  2. Work in an inch of leaf compost or peat moss to improve drainage
  3. Install raised beds
  4. Select another spot if the area is exceptionally poorly drained or located in shallow bedrock.
  • Most culinary herbs grow poorly in an acidic soil and prefer the pH to be 6.5 to 7.0. Visit the UConn Soil Nutrient Analysis Laboratory site for information on soil testing.
  • Limestone can be used to adjust the soil pH if necessary. Ground or pelletized limestone can be applied any time the soil is not frozen and will slowly raise the pH. Allow 6 months to a year for the limestone to act and the soil pH to be raised. Wood ashes can be used as a substitute for limestone. Check the pH level with a soil test before planting as over-application of limestone or wood ashes can result in a soil that is too alkaline for herbs.
  • Herbs are most flavorful when grown on the lean side so do not over-fertilize them. Excess fertilizer will promote lush green growth with little flavor. Use a synthetic fertilizer such as 5-10-10, or a natural organic one at the rate recommended on the label unless otherwise directed by a soil test.
  • To start herb seeds indoors sow seeds in a light, well-drained soil in shallow boxes in late winter. Do not cover the seeds too deeply. The finer the seed the shallower the sowing. Transplant seedlings outdoors in the spring. Water with a fine mist to avoid washing away the soil.
  • Fresh leaves should be picked as soon as the plant has enough foliage to maintain growth. Only remove about one-third of the foliage at each harvest. Early morning is best to ensure that the oils are not dried out from the sun. To dry herbs for winter use the leaves should be harvested prior to flower buds opening.
  • Container herbs will require more moisture than garden-grown herbs and may benefit from late afternoon shade.
  • Most herbs to do not have many pest problems.

Basil (Ocimum basilicum)

Description: Annual. Height 1-2 feet. An accent culinary herb that is easy to grow.
Culture: Well-drained, soil in full sun.
Propagation: Seed can be directly sown after the danger of frost has passed or started indoors 6-8 weeks before planting outside. Plants should be thinned to 6-12 inches apart.
Tips: Prune periodically to maintain growth and do not allow it to flower for the best leaf flavor but know that the flowers are very attractive to pollinators so allow a few plants to bloom if possible. Usually just the leaves are harvested but the seeds may also be used in Thai foods. Basil can be used fresh, dried (flavor will be lessened) or frozen and is the main ingredient in pesto.

Bay (Laurus nobilis)

Description: A perennial tree in more southern climates, bay plants need to be overwintered indoors in the New England area.
Culture: Typically; bay is grown as a potted plant which can be placed outdoors in the summer. Keep in mind that if plants summer outdoors they may be more susceptible to scale insects. Bay prefers a fertile potting mix with a pH of 6.2 or so.
Propagation: It is difficult to propagate from seeds or cuttings. Plants are usually purchased from a local garden center. Bay can be trained as a topiary or left as a multi-stemmed small shrub.
Tips: Bay is susceptible to white wax scale which makes the leaves sooty and retards leaf growth. The best time to treat for scale is in late May when the crawlers hatch and have not developed their waxy cover. Apply a pesticide labeled for scale in early June. Horticultural oils may be used to control adults. Repeat applications are often necessary. Bay leaves, although inedible, are used in cooking to provide flavor, in herbal wreaths or potpourris, or in bath water. Remember to remove bay leaves before serving a dish. May be dried.

Chives (Allium schoenoprasum)

Description: A culinary and ornamental hardy herbaceous perennial.  Height: 10-15 inches. An erect plant with fine green leaves and lavender flower heads.
Culture: Chives will tolerate a wide variety of soil conditions and are hardy in zones 3-9 although it will die back to the ground in colder areas. Divide when clumps get too large. Deadhead flowers before they set seeds. Many seeds will sprout the following year and they are difficult to weed out of beds.
Propagation: Chives can be propagated by seed or division in the spring or fall.
Tips: Chives are great snipped fresh onto potatoes and in salads. Chives have no usual pests or diseases and can be deer-resistant. Do not dry chives, freeze in an air-tight container.

Cilantro/Coriander (Coriandrum sativum)

Description: Cilantro and coriander are two annual culinary herbs on one plant. Cilantro is the green leaves and coriander is the seed.
Culture: Does well in any well-drained garden soil.
Propagation: Direct sow seeds into the garden. Plant the seeds one inch apart after the danger of frost has passed. Plants do not need to be thinned.
Tips: Cilantro, a main ingredient in salsa, is harvested by cutting at the base of a cluster of leaves prior to flowering. For coriander, allow the plant to flower and form seeds. Remove seed heads when they start to brown but before they shatter, about 90 days from planting. After drying, remove the seeds by rubbing the heads in your hands. Coriander seed is used in sausage, salads and bread or in potpourris.

Dill (Anethum graveolens)

Description: Annual. Height 2-3 feet. Bluish-green stems, yellow-green leaves and yellow umbrellated flowers.
Culture: Dill prefers full sun and a well-drained soil. Purchase plants and set into garden while young or sow seeds. Plants typically self-seed and once established will come back each year.
Propagation: Dill has a taproot and therefore should be sown directly into the garden. Sow seeds in the spring one to two weeks before the last frost and then make successive sowings every two weeks during the growing season. Stake the tall plants.
Tips: Both the foliage and the seeds are useful in the kitchen. The foliage and seeds can be harvested at any time, used fresh or dried.  Can attract beneficial insects such as hoverflies, predatory wasps and swallowtail butterfly caterpillars. Tomato hornworms are also attracted to dill so it should be planted at a distance from tomatoes. Dill repels aphids and spider mites. Dill is a great companion to cucumbers and onions.

Fennel (Foeniculum dulce)

Description: A culinary perennial herb with an anise-like flavor that is usually grown as an annual. Height 3-4’.
Culture: Full sun. Plants may overwinter in mild winters if mulched after the first frost, uncover when new growth appears in the spring. Prefers a soil pH around 6.5.
Propagation: Fennel grows easily from direct-sowed seed in the spring. Sow in rows 3’ apart. Thin plants to 12” apart and stake when 18” tall.
Tips: Pick seeds when ripe for use in cooking, cheese spreads and vegetable dishes. The stalks can be eaten like celery and are best before they blossom. Fennel will attract beneficial insects that feed on aphids.

Lemongrass (Cymbopogon citratus)

Description: A perennial in more southern climates but generally needs to be overwintered indoors as a pot plant in the New England area. 3-6 feet tall and 3 feet wide.
Culture: Full sun, warm and humid conditions. Lemongrass should be watered and misted regularly.
Propagation: Lemongrass should be planted 3 feet apart. After the final harvest or before the first frost save a 6-inch section of the bulbous shoot base with attached roots. Divide and pot into smaller containers that can be overwintered indoors.
Tips: Lemongrass is widely used in Asian cuisine. To harvest, cut the stems at ground level and use the tender inner core in cooking. The leaves can also be used to flavor teas, soups and sauces. Feed weekly with a half-strength solution of a balanced fertilizer from June through September. Lemongrass has few insect pests but is susceptible to leaf blight and little leaf. Both of these can be treated with a fungicide.

Mint (Mentha)

Description: Perennial. Height 1-3 feet.
Culture: Moist, well-drained soil. Does well in in shadier sites and over a wide range of soil pH.
Propagation: Divide each spring so mint does not overrun your garden.
Tips: Can run rampant over your garden and should be either placed where this habit will not be a problem or contained by annual division or some type of containment system. One option is to plant mint in a bottomless five-gallon bucket sunk into the ground with only the top couple of inches peeking out. Harvest leaves before flowering. Use fresh or dried in teas and baked goods.

Oregano (Origanum vulgare hirtum (formerly O. heracleoticum)

Description: Hardy perennial. Height 2 feet. Light green oval leaves with a downy underside, white flowers in terminal clusters.
Culture: Well-drained, medium-rich soil in full sun. Mulch after the first frost, uncover when new growth appears in the spring.
Propagation: Cuttings. Divide plant every third year.
Tips: Make several harvests in early summer. Then let plant flower to attract bees and other pollinators. For true oregano, make sure to confirm the Latin name. Can be used fresh or dried.

Parsley (Petroselinum crispum)

Description: Annual/biennial. Produces edible leaves the first year, blooms the second year, produces seed and dies. Height 8-16 inches. Bright green leaves.
Culture: Well-drained, medium-rich soil. Full sun.
Propagation: Direct sow or in peat pots, slow to germinate. One year old parsley imparts a much stronger flavor than leaves produced the second year so it can be treated like an annual and replanted each year.
Tips: Favored by swallow tail butterfly caterpillars so, if possible, leave second year parsley as host plants.

Rosemary (Rosmarinus officinalis)

Description: Tender perennial that should be overwintered indoors in New England. Height 1-3 feet. Dark green, aromatic, needle-like leaves.
Culture: Well-drained, medium-rich, alkaline soil. Full sun.
Propagation: Seed is slow to germinate, can be propagated by cuttings.
Tips: A strong culinary and aromatic herb. Can be used fresh or dried.

Sage (Salvia officinalis)

Description: Perennial. Height 18-30 inches. Gray-green oblong leaves, purple flowers on loose spikes.
Culture: Well-drained, medium-rich, alkaline soil. Full sun. Mulch after the first frost, uncover when new growth appears in the spring.
Propagation: Seeds, cuttings, division.
Tips: Harvest the leaves for culinary purposes. Other varieties such as silver, gold, purple or variegated sage are beautiful in the herb or ornamental garden but less flavorful and less hardy. Can be used fresh or dried.

Tarragon (Artemisia drancunculus)

Description: Hardy perennial. Height: 18-30 inches. Smooth olive-green, narrow leaves.
Culture: Well-drained, medium-rich soil. Full sun but will tolerate partial shade. Does not do well in hot, humid climates.  Susceptible to powdery mildew. Needs protection in harsh winter climates. Mulch after the first frost, uncover when new growth appears in the spring.
Propagation: Cuttings/divide. Does not set seed. Divide or make new plantings every 3-4 years.
Tips: Fresh leaves have the most flavor especially when steeped in vinegar. Use fresh or freeze in air-tight containers for the best flavor.

Thyme (Thymus vulgaris)

Description: Perennial. Height 6-10 inches. Leaves are small, oval and gray-green in color.
Culture: Light, well-drained, alkaline soil. Full sun. Good in raised beds. Mulch after the first frost, uncover when new growth appears in the spring.
Propagation: Cuttings, division or direct seeding. Thin plants to 8-12 inches apart. Make new plantings every 3-4 years.
Tips: Many varieties with captivating flavors. Cut leafy tops and flower clusters when first blossoms open and dry. Requires annual renewal pruning. Goes well with meats and stews. Can be used fresh or dried.

For pest and disease management please visit the UConn IPM Pest Management for Herb Bedding Plants Grown in the Greenhouse. Despite good cultural practices, pests and diseases at times may appear. Chemical control should be used only after all other methods have failed. For pesticide information please call UConn Home and Garden Education Center weekdays, in Connecticut call toll free 877-486-6271.  Out of state call 860-486-6271.

Revised by the UConn Home & Garden Education Center, 2016.