Horticulture Principles and Practices

648 Chapter 21 Herb Gardening
21.2.2 SOIL PREPARATION
Raised beds should be used where drainage is poor. If required, soils should be limed to
reduce acidity. Herbs may be grown in containers in the kitchen using regular potting
mixes; such herbs are readily accessible for culinary use (Figure 21–1).
21.2.3 DESIGN OF AN HERB GARDEN
Herbs, as mentioned previously, have both ornamental and culinary uses. For ornamental
purposes, and like other ornamental species, herbs may be set in a formal design in
the landscape by judiciously selecting species according to the principles of landscaping.
Herbs may be arranged in a fashion similar to bedding plants. In herb gardening,
themes are important in creating attractive designs. These themes should take into
account the adaptive characteristics, along with growth habits and other botanical features
such as flower color. A popular design is the checkerboard, in which the site is
divided into squares with walkways between squares and each square planted with one
species.
21.2.4 PROPAGATION
The most common method of propagation of herbs is by seed. Herbs have not
received the attention that vegetables and many important field crops have from the
standpoint of breeding and improvement. As such, wild characteristics may be present
in some species, making their germination unpredictable and sometimes very
poor. Species with some degree of germination problems include rosemary, lavender,
catnip, mint, and winter savoy. Instructions on seed packs should be followed with
care. Vegetative propagation (by cuttings or division) may be used in propagating certain
seed-bearing plants; it is the only method for seedless species such as French tarragon.
Mints are widely used in the confectionery industry and have received some
attention in terms of improvement. They are often propagated from division of rootstocks
and runners to make them come true to type. Tansy and bergamot are also
propagated from root division.
21.2.5 CARE
Herbs, being relatively wild, are quite hardy and can be produced on marginal soils, eliminating
or reducing the need for additional fertility in cultivation in many cases. Herbs,
such as basil, chives, and parsley, whose foliage is frequently cut benefit from moderate
fertilization. Mulching improves moisture retention and suppresses weeds.
Herbs grown in restricted areas in containers generally need more attention than
those grown in beds. They are more likely to experience moisture stress and also more
prone to danger from excessive moisture. Herbs that do best indoors are those with preference
for low light, unless artificial light supplementation is provided. They may be
grown in window boxes or hanging baskets. Few diseases and pests are a problem in herb
cultivation. Chives and mints are known to be susceptible to rust attacks. Under damp
conditions, fungal diseases such as molds, mildews, and rots may occur on some herbs,
as is generally the case in many plants in cultivation.
21.2.6 HARVESTING AND DRYING
Herbs may be used fresh or cut and dried. For culinary uses as seasonings, young
leaves should be picked. Plants attain peak flavor when flowers open, which is the
best time for harvesting for drying of stems and leaves. The plants to be dried are cut
when leaves exhibit no moisture. Slow drying at low temperatures produces the best
results. Drying is done not in the sun but in a well-ventilated dry room or in an oven
at low temperature. This drying condition helps to retain the green color, essential
oils, and aroma of the leaves and stems. Seeds are harvested when brown or black by
cutting the stems. The stems are then hung upside-down over a receptacle so that