When To Sow: Feb-April Harvest: August-October
Germination: 7-14 days Full Sun
Starting Indoors: Sow 6 weeks before your last spring frost. Using a well-drained seed starting mix, lightly cover and place in a bright, sunny location or supplement with artificial light. For ideal germination, soil temperatures should be between 18-21c. To aid germination, place the tray in a plastic bag or place a thin layer of plastic over the top to keep the soil moist.
Once your seedlings have 2-4 true leaves, transplant into a larger container and apply a good feed.
Transplant outside or into permanent pots once the soil has warmed—the outside temperatures should be no colder than 10c at any given time. Plant in well-drained soil, 1-2’ apart, in rows 2-3’ apart, or spaced about 14-16” apart in raised beds.
Please note the above and below content is for sowing and growing basil as a traditional crop using traditional sowing methods. Basil can in fact be sown and grown all year round. As long as you sow basil directly to pots and keep those pots on a window or in a greenhouse you can enjoy a fresh basil harvest all year.
Direct Seed: Not recommended.
Maintenance
Water daily, especially if planted outside. (It’s almost impossible to overwater basil planted outside.) For potted basil plants, water until the soil is wet to a depth of about 1½ inches. Water at the base of the plant and add mulch for water conservation.
Though it will grow in moderately fertile soil, basil tastes best if well fed. If you want your basil to keep growing and producing leaves, keep feeding it. It’s helpful to have a ready supply of worm castings and compost on hand.
For a continual supply of fresh leaves, pinch off flower heads as soon as they appear.
Harvesting
Harvesting can begin as soon as the plant is 6-8” tall. The best way to harvest is by pinching off the tips (which you will need to do anyway to prevent it from flowering). You can also harvest individual leaves.
If you’re growing basil outside, harvest all of it at even the slightest predication of a frost. You can dry basil leaves, but freezing them or using putting them in vinegar will preserve its flavor the best. You can also use it to flavor oils and pesto, both of which should be kept refrigerated or frozen. (But don’t put fresh leaves in the refrigerator! They’ll turn brown.)
Companion Planting: Basil is an especially great companion plant for tomatoes and will improve its flavour. They also help peppers, oregano, asparagus, and petunias. It will also make your tomatoes taste better.