Sweet Basil (Ocimum basilicum L.)
All basils are tender annuals and are very susceptible
to cold weather. Basil should only be planted when there is no danger of frost.
Basil should always be grown in full sun, and in warm
well drained soil. Raised beds are highly recommended as they promote good
drainage and warm quickly. A good sandy loam soil is preferred. Basil
can be grown with a soil pH of 5.5 to 7.5 with a 6.5 average to be the
best. Basil can be planted from direct seeding or from transplants.
With direct seeding seed should be no deeper than .63
cm. From direct seed plant emergence should be between 8 to 14 days. Plant
spacing should be 30.48 cm plant to plant. Row to row spacing should be from
60.96 cm to 91.44 cm. If transplanting, plants should be 15 cm tall.
During the growth cycle, if more than one harvest is
required, pinching of the flowers is important to keep the plants growing and
bushy past its standard growth cycle.
Basil will not tolerate moisture stress. Provide a
regular and even supply of water through the crop length.
Weed control in basil is critical. Competition with
weeds decreases the quality of the fresh or dried leaves.
Although many insects enjoy basil, Grasshoppers and
Caterpillars are its main predators.
The rate of fertilizer application will depend on soil
type and prior history. It is suggested that an N/P/K ratio equivalent of 1/1/1
be used at a rate of 109/109/109 kg per hectare. It is recommended after
the first harvest an additional application of 25 kg Nitrogen equivalent be
Basil’s main disease is Fusarium. There are no
products to help control this disease. One basil variety is available with
tolerance to Fusarium. Once a field has become infested with the Fusarium wilt
pathogen, infected propagules may persist in the soil for 8-12 years. All basil
and members of the mint family are affected by this disease.
For harvesting, the terminal 5.08 – 7.62 cm long
whorls of leaves may be cut or pinched off once or twice a week. This provides
a high quality product with little stem tissue present. Basil can also be cut
and bunched like fresh parsley. A good crop of basil can yield as much as 6
tons per hectare dried or 20 tons per hectare fresh. For dried basil
temperatures below 40º C should be used, and drying should be done in darkness
to retain maximum color.