Basil, the common name forOcimum basilicum, is a popular sweet herb of the Mint Family esteemed for flavoring and formerly used for medicinal purposes. An annual of the tropics, it is tender and should not be attempted outdoors until the weather is warm.
Basil grows easily from seed which may be sown in the garden or started indoors. Basil also grows well indoors under fluorescent and HID plant growing lights.
The small flowers are white or purple, but the plant is grown for its sometimes purple tinged leaves, which are cut during the growing season and used fresh or dried in bundles.
Plants should be transplanted or thinned to stand 6 to 10 inches apart; they prefer a quick draining, light soil in a warm location.
Although basil will grow best outdoors, it can be easily grown indoors in a container or hydroponic planter and, like most herbs, will do best on a south-facing windowsill (in the Northern Hemisphere). It should be kept away from any drafts, and must have plenty of sunlight, therefore a greenhouse or cold frame is ideal if available.
Basil plants whose leaves have wilted from lack of water will normally recover if they are watered thoroughly and immediately placed in a sunny location.
Basil can also be propagated very reliably from cuttings.
Leaf production slows or stops on any stem which flowers, so you should pinch off any flower stems to keep the plant in production, or pinch off some stems while leaving others to bloom for decoration or seeds. Once you do let the plant flower, it will produce seed pods containing small black seeds which you can save and plant the following year. Picking the leaves off the plant helps promote continuouse growth, largely because the plant responds by converting pairs of leaflets next to the topmost leaves into new stems.
Outdoors, containers (sow direct in final pots, or in plugs and later transplant to final pots), hydroponics. Nighttime temperature must not go below 10°C.
Basil usually grows to a height of 12 to 18 inches (30 - 45cm).
Basil plants should be spaced between 9 and 12 inches (22 and 30 cm) apart.
Preferred pH Range
Basil will grow in a very wide pH range between 5.1 (strongly acidic) and 8.5 (alkaline) with a preferred range of 5.5 (strongly acidic) to 6.5 (mildly acidic).
Sow seed indoors before last frost or direct sow outdoors after last frost. Basil is easily propagated through herbaceous stem cuttings.
Seed Germination Period
5 to 10 days.
Seeds Per Gram (Approximate)
500 - 1000.
Well drained, average to rich soil.
Alternative Growing Media
Soilless potting mixes, perlite, vermiculite, rockwool, coco peat, Oasis foam.
Time From Seed to Saleable Plant
Seeds to finished plugs, 8 weeks; plugs to saleable plants, 5 weeks.
Sun & Lighting Requirements
Basil grown outdoors prefers full sun.