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HERBS |
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KEY CONCEPTS
III. Growing Herbs
GROWING HERBS
Most herbs, particularly annuals, can be grown from seed. Direct-sow the seeds or start them indoors. Borage, anise, caraway, chervil, coriander, cumin, dill and fennel are somewhat difficult to transplant and should be direct sown. Use the methods described in Chapter 5 on Plant Propagation to grow herbs from seed.
Following the general instructions in Chapter 5 for seed starting, sow seeds indoors the recommended number of weeks before setting out in mid-May. Some perennial seeds take 6 to 8 weeks just to germinate. Factor this into determining when to sow indoors. Instructions on the seed packet provide information on when to sow. Follow packet instructions for light or darkness to germinate (covered or uncovered) and any special treatments, such as soaking, chilling or scarifying.
Harden off seedlings when four true leaves have formed. Use a 1/4 strength water-soluble fertilizer solution when the plants are transplanted into the garden. If you are tempted to rush the transition to outdoors, remember that herbs generally do not thrive in cold soil.
Many perennial herbs can be propagated by division, layering and cuttings. Divide perennial herbs that begin to decline to maintain plant health and vigor.
Early spring is the best time to make divisions. Dividing can also be done in early fall. Dig and lift the parent plant. Depending on size, cut or break apart sections of the crown and roots. Then replant. Bulbous roots of chives and garlic can be pulled apart and replanted. Fleshy-rooted herbs, such as horseradish, ginger and lovage, should be dug up and sliced apart with a sharp knife, then replanted.
Many herbs also can be propagated easily by layering. These include rosemary, marjoram, chamomile, horehound, hyssop, sage, santolina, clove pink, winter savory and thyme. Select branches near the base of the parent plant. Pull off side branches and leaves and press the stem into the soil. Weight it in place with a stone or pin it with a wire. Keep soil moist until the layered stem roots. Sever the newly rooted plant from the parent and move it to its new location.
Many herbs can be started from cuttings. These include scented geraniums, lavender, rosemary, lemon verbena, curry plant, hyssop, clove pink, rue, santolina, artemesia, sage, myrtle and shrubby thymes.
Take 3-inch stem cuttings from healthy, nonwoody shoots. Cut below a node. Remove foliage from the bottom half of the stem and treat as outlined in Chapter 5 on Plant Propagation.
Most herbs grow and produce satisfactorily when they receive
l inch of water per week by rainfall or supplemental watering. Some herbs, such as mint, rosemary, chervil and sweet woodruff, prefer more moisture. Others, such as lavender, artemesia, sage, thyme and oregano require less moisture. Use a 1 to 2 inches of organic mulch to conserve soil moisture.
Fertilization of most herbs should be done sparingly. Many herbs will produce poor quality aromas and flavors if heavily fertilized. Apply fertilizer based on soil test recommendations. Apply inorganic fertilizers once in midsummer. Use well-rotted manure early in the season as a slow-released source of nutrients. Lavender, thyme, rosemary and rue do best in an alkaline soil. Follow the recommendations of a soil test when adding lime.
Since many herbs develop their best aromas or flavors just before or at bloom time, removing flower buds maintains peak quality. For those herbs that are annuals, deadheading is necessary to maintain plant growth. When annuals form seeds, they usually stop producing new growth. Remove blossoms prior to bloom to maintain quality. Basil and mint are examples of herbs that must be continually deadheaded to maintain leaf production. The exceptions are herbs raised for their seed, like caraway and coriander. Coriander is also called cilantro. Its leaves are used in Hispanic cuisine.
Certain herbs, such as dill and fennel, will self-seed. Gardeners may find seedlings throughout the garden if plants are not deadheaded before seeds ripen and scatter.
Herb aromas and flavors come from combinations of chemicals that are affected by preserving. Some chemicals are lost while others become more prominent. Coriander seed is a good example of this "ripening." It is picked slightly green when it smells spicy-waxy. When fully ripe and ready for use as a seasoning, it has changed to sharp, spicy-sweet.
Time of harvest is critical to capture peak flavor. It is difficult to judge when an herb is ready for harvest by looking at it. Test each plant by smelling or tasting. Your own senses will tell you if the flavor level you want has been reached.
There are some general rules for harvesting herbs for preserving. Harvest for fresh use is not dependent on these rules.
1. Never harvest when wet from either dew or rain. Harvest in the morning on a dry, sunny day, after the dew has dried. Foliage, petals, pods and bark must be dry.
2. Harvest herbs by early afternoon. Transpiration occurs late in the day, lowering levels of the aromatic chemicals as moisture leaves the plant.
3. Harvest leaves just before flowers bloom. Fragrances that attract insects for pollination will be at their peak. Harvest flowers, such as roses and lavender, before blooms are fully open. Gather seeds as color begins to change from green to brown or gray.
The flavors and aromas in herbs are volatile. This means they are readily released as gases into the air. Store herbs so their volatile nature is protected. If herbs are stored carelessly, they lose their flavor or aroma and become useless.
Freezing in airtight containers can retain the flavor of many herbs up to 6 to 8 months. Freezing methods retain more flavor than other methods.
Drying is the most popular method of preserving herbs. However, drying will reduce some of the desired flavor or aroma. An oven or microwave can speed the drying process, but this method must be done carefully or much of the flavor and aroma may be lost.
Air-drying is the simplest method of all to preserve herbs. To dry leaves, choose disease-free foliage and cut stems with leaves attached. To dry smaller amounts, place stems in a single layer on paper toweling or cheesecloth in a well-ventilated room out of direct sunlight. Stir or turn once or twice a day until dry and crumbly. Exposure to moist air and crushing will reduce the quality of herb essences. Generally, the more SUCCULENT the plant, the longer it will take to dry.
To dry larger amounts, tie bunches of stems together with string or rubber bands. Hang the bunches in a warm, dark, dust-free, well-ventilated area. Herbs grown for seed, such as dill, fennel, coriander and caraway, can be dried on screens or inside brown paper bags.
[illus. of drying herbs in bunches, and inside paper bags]
When leaves are dry and crisp, strip them from stems and store in appropriate containers. Seeds are dry when they fall from the seed head. All plant tissues must be thoroughly dry before storing. Store herbs in opaque or dark glass containers with tightly fitting lids. If containers are clear, store out of direct sunlight. Store all herbs in a cool place, not next to the stove.
Herbs seem to be less susceptible to pests and disease infection. The fragrance and flavor of herbs have evolved over the years to defend or perpetuate the life of these plants. Chemicals in herbs may attract or repel insects, or warn animals not to nibble.
However, herbs are not immune to insects and disease problems. Protect new seedlings from cutworms. Damping-off is a problem when seeds are sown in unsterile soil. Use the same methods of protection for these problems as you would with flower and vegetable transplants.
Follow good sanitation practices to maintain disease- and pest-free herbs. Maintain a weed-free garden. Mulch with 1 to 2 inches of organic matter, such as humus or grass clippings, to control weeds, as well as to retain moisture. Native Mediterranean herbs, such as rosemary, thyme, sage and lavender, may grow better when mulched with a layer of gravel or small pebbles.
Many herbs are susceptible to aphids, whiteflies and spider mites. Certain herbs may be eaten by slugs. Handpick, trap, and spray with water to control these insects. If herbs are to be eaten, special care must be taken in pesticide use. Use pesticides only if the herb is listed on the label. Wait the number of days specified between application and harvest.
Rots, mildews and wilts will attack herbs, especially if plants are spaced too closely or grown in poorly drained soil. Poor ventilation and soggy soils promote fungal and bacterial growth above and below ground.
Rusts also attack many herbs.
Good cultural practices reduce the chance of infection by disease-causing organisms. Prompt cleanup of debris will reduce the populations of disease-causing organisms in the garden. Practice crop rotation of annual herbs to avoid growing the same herbs in the same place year after year.
For successful herb growing, know the particular cultural requirements of each plant you choose. Fact Sheet 1627 provides specific growing instructions garlic, Reference Herbs.2.
How do you know if you are using an herb or a spice in cooking? Herbs grow in TEMPERATE regions, and spices come from TROPICAL regions. Generally herbs are fresh or dried leaves, while spices involve seeds, roots, fruits, flowers and bark. Herbs are green and have a milder flavor. Spices tend to be brown, black and red, with a stronger, pungent flavor. However, the terms herb and spice are artificial categories and not of major concern.
A non-culinary, general definition of an herb is any useful plant.
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