Holy basil grows up to 0.5-1 m high, depending on growing
conditions. Tulsi is a perennial in tropics but is best treated
as a half-hardy annual here as northern European light levels
are insufficent during winter for it to keep growing. It has
long purple flowers and smooth green foliage with a spicy
fragrance. Harvest young shoots in early morning for maximum
flavour and scent. Half-hardy annual, usually best under cover
on a sunny windowsill or a greenhouse, even during the summer,
but can be grown in a sheltered place outdoors in mild areas.
Minimum temperature 18ºC. Sow in moderate heat, 18-20ºC/65-70ºF,
during April-May using any good seed compost with added 1/3
extra sharp grit for best results. Cover seed very thinly with
sieved compost or vermiculite. If plants are very well
established and growing in a greenhouse, you may be able to save
seed to keep for next year, which may be easier to germinate
than bought seed. Otherwise, remove spent flowers to prolong the
life of plant. As seedlings are large