Basil does not like the cold, and is not resistant of temperatures below 10 degrees celcius. However, in climates with very warm summers the plants will appreciate a little shade. The soil should be moist, fertile and well-drained. If planting outdoors, your basil plants will also prefer to be planted where there is shelter from the wind.
Basil is generally only grown from seeds, and is very difficult to transplant from cuttings. The seeds
can be planted at the start or middle of spring, ideally in March but if not then, any time between
February and May in the Northern Hemisphere. They will do prefer a gentle warmth in the air, so for
best results, plant the seeds in seed trays or individual pots in a conservatory or greenhouse, at a
temperature of around 20 degrees Celcius. A good soil with balanced nutrients will help your little
seeds in their early days of growth.
When the seedlings have formed more than 4 leaves, the tips should be pricked. If you have originally
used seed trays to grow multiple seeds together, separate the plants out into individual pots or boxes
and keep them in their place in the conservatory or greenhouse, or behind a warm, draught-free
windowsill until the winter and spring chills have gone from the soil outdoors and there is no expectation
of further frosts. Then, around the end of may or beginning of june when the plants look like they are
ready to make the move outside, it's time to start thinking about moving your plants outdoors. Harden
them off first, over a period of about a week or so. There are different ways of doing this, but you may
find that taking the plants outside during the day for the first few days then returning them indoors at
night is the best...then gradually increase the time they spend outdoors until they're used to being out
there all the time. Once hardened off, your plants can be transplanted into the garden outdoors. When
planting into their final outdoor home in your garden, they should be kept about a foot apart from each
To prolong the life of the plants until late in the season, the flower-stems should be cut as they rise.
Many gardeners lift their basil plants in September, pot them, and thus maintain a fresh supply of green
leaves until winter is far advanced. However, in mild areas you may be able to overwinter your basil
plants in your garden, if you protect them well against winter frost a cloche or similar covering.