|
GENUS: Stevia
FAMILY: Asteraceae
SPECIES: rebaudiana
COMMON NAMES: sweetleaf, Khaa Jee, Caa-he-e
PARTS UTILIZED: leaves
ORIGIN: Paraguay, South America
LIFE CYCLE: Perennial but grown as an annual in northerly climates
DESCRIPTION: growing two feet tall this shrub produces small white flowers
Stevia is quite
tolerant of most soil types but it does prefer a sand/loam soil. The
stevia feeder roots are close to the surface, so if using a sandy
soil, place compost around the base for extra nutrients. The soil
should be well drained so that the roots do not soak, frequent smaller
waterings is preferable. Raise the soil around the base and cover with
mulch to protect the roots from the heat of a summer sun.
It is best to
fertilize the soil before planting and again every 3 weeks with a
fertilizer low in nitrogen or releases nitrogen slowly such as organic
fertilizers. High nitrogen content or chemical fertilizer will produce
quickly grown large leaves that will have little flavour.
Stevia requires
12-16 hours per day of sunlight, but is sensitive to excessive heat or
low temperature. If wintering indoors, a grow light is usually
recommended. Wait until outside soil temperatures have risen in the
spring before planting stevia outdoors.
Propagation from cutting is
usually successful. Place plants 18" apart and rows 22" apart. To take
a cutting from the mother stevia plant, snip off 2" and strip all
bottom leaves of your cutting. You may dip the stem in a rooting
hormone or place directly in good potting soil. Make sure none of the
leaves are touching the soil. The rooting will begin at the leaf
nodes. Grow lights may be required, or keep the cutting moist and warm
with the use of plastic wrap placed loosely around it. As your plant
grows, pinch the tips monthly to encourage side branching.
The best time to
harvest stevia is just as it starts to bloom or just before the first
frost, this is when the stevioside content is the highest. Cut the
entire plant at the base and hang upside down in a warm, dry and airy
room. After 2-4 days you may run your fingers through the stems to
loosen the dried leaves. Store the leaves in a dry location and they
will last until the next harvest.
Two fungal
diseases, Septoria steviae and Sclerotinia sclerotiorum, have been
reported in stevia grown in Canada (Lovering and Reeleder 1996; Chang
et al. 1997). Septoria disease was characterized by depressed,
angular, shiny olive gray lesions, sometimes surrounded by a chlorotic
halo, that rapidly coalesce. Sclerotinia disease was characterized by
brown lesions on the stem, near the soil line, followed by wilting and
eventually by the complete collapse of affected individuals. No means
of controlling these diseases have yet been published. Since stevia is
very slow to establish and does not compete well with weeds,
herbicides or other means will be essential to control weed growth to
produce ample yield and a clean crop. The herbicide trifluralin
appears to be well tolerated by stevia (Katamaya 1979).
Click here for information on purchasing Stevia
Seeds
To read further studies completed by the Canadian Government regarding
the trial crop growing of stevia, please following one of these links:
Heritability for Yield, Leaf:Stem Ratio
and Stevioside Content Estimated from a Landrace Cultivar of
Stevia
rebaudiana
Stevia rebaudiana: Its biological,
chemical and agricultural properties
Stevia, Nature's Natural Low Calorie
Sweetener
The Cultivation of Stevia, "Nature's
Sweetener"
Medicinal Herb Garden
|
