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Time
Therapeutic efficacy
varies during different times or seasons of the year. The constituent
and active principles vary quantitavely at different seasons of
the year and the majority of plant materials are usually best
collected during the dry season, when the herbs are at peak maturity
and concentration. Dry as quickly as possible, away from bright
sunlight, to preserve the ingredients and prevent oxidation.
Roots and rhizomes: Best collected October to February,
when the plants are more vigorously storing food in their underground
organs.
Leaves: The most opportune time is when the plant is about
to bloom.
Flowers: Buds are preferred, best collected
in the morning after the morning dew has evaporated; flowers,
just before or shortly after opening. Dry the herbal materials
as quickly as possible.
Bark materials and stems: Generally, best gathered in summer
time. When the climate is warm and humid, the bark of any plant
usually contains richer nutritive substances including the medicinal
metabolites. Preferably, barks and stems should be removed only
from fully grown plants. Do not remove all the bark or a band
of surrounding bark.
Fruits and seeds: Fully ripened fruits and mature
seeds are preferred. Collection of pod fruits is done in the morning
to avoid unnecessary opening up of the fruit wall to the detriment
of losing the seeds. Turn the fleshy fruit frequently for even
drying.
Whole plant: When the whole plant is desired,
it is advisable to harvest the plant at the time when the flowers
are all in bloom. Old and withering plants are less effective
when used as a source of drugs.
Habitat
Information about
the whereabouts of the plants, especially the rare ones, can facilitate
the search for them. It saves both time and energy. Low altitudes
probably range from sea level to about 300 meters; medium altitudes
from about 310 meters to about 1000 meters; and high altitude
from about 1000 meters and up.
Storage
Many medicinal plants
are seasonal, some not easily accessible, available only in deep
forests or mountain peaks. Such restrictions necessitate ways
and devices to store them for future use. Dirt and other foreign
substances should be removed. If washing is needed, it should
be done quickly to minimize deterioration and loss of active substances.
As a rule, all parts of the plant collected should be dried as
soon as possible to avoid unnecessary waste of the drug materials
through natural processes of denaturation, decay and fungal attacks.
Some commonly used storage methods used buy the Chinese are as
follows:
Sun-drying method: Spread the herbs over the dry
beaches, patio or benches that are under the direct scorch of
the sun until the materials turn dry and brownish.
Shade-drying method: Some plant materials are preferably
dried under shade at room temperature by wind action- because
of heat-labile substances that they contain. As such, free circulation
of air is important. Drying processes should be shortened, if
higher drug contents are to be sought for. Floral and fruit materials
should be dried by this method.
Heat-drying method: Some materials may be placed over
an oven and dried under the intense heat released or under regulated
soft heat. Plants that contain high sugar and starch are best
preserved by this method. In places where the rain falls throughout
the year, this method is strongly recommended.
Other Special Methods: Succulent materials are usually
washed first in boiling water or steam-cooked in a container before
actually drying it. For spiny and hairy materials, remove the
unwanted appendages. Some plant materials (ex. succulent materials)
may require cutting or sectioning before drying. In general, the
moisture content of the dried plant materials should be less than
10% before storage. Moisture content higher than 10% usually leads
to growth of microorganisms and pest infestation with consequent
drug deterioration.
The dried plant materials should be placed in plastic containers or tightly covered bottles; brown colored bottles are preferred as they minimize deterioration due to sunlight. Dry charcoal (separated from the medicinal plant) may be placed inside the bottles to absorb moisture. The storage place should be dry, well-ventilated, and spacious, lest fungi and insects may invade rampantly. Drug materials (dry ones) after proper processing can be kept in large open wooden shelves. The humidity of the storehouse should then be as low as possible. Materials rich in volatile oils are advised to be kept in airtight containers. Otherwise, their efficacy will decrease as time passes by. If all factors are favorable, the prepared drugs can be used even after years of storage.
Preservation
and Conservation
Know how to preserve
and conserve plant sources. Complete depletion of all medicinal
plants founds in an area should be avoided. Once collected, all
the materials should be processed at once for long storage. Well
planned activity in the collection of plant materials will always
prove to be economical and advantageous in the long run. Cultivation
of these medicinal plants should be tried in places where conditions
favor because cultivated plants contain higher percentages of
the medicinal principles desired.
