Basil seeds are viable for about 8 years and are tiny; about 23,000 basil seeds weigh an ounce.
Sowing Basil Seeds.
Due to their small size, basil seeds are best sown in flats with a light covering of soil. Water flats from the bottom until surface shows a wet spot. When basil seedlings are about an inch tall, thin so that each plant is two inches apart.
Don't miss our
Basil Companion Planting Guide to explore companion planting with basil.
Transplantation.
Once your basil seedlings are 3 inches tall, transplant to your garden where they should be planted a foot apart in rows separated by 15 to 18 inches. Can be also used as border plants, but this may require a bit more tending and removal of weeds between the plants. Basil prefers a sunny location with light fertile and somewhat dry soil that's as free from weeds as possible. When plants in adjoining rows meet, cultivation may stop.
Harvest.
You can begin gathering foilage in midsummer when the plants start to flower (once the basil plants flower the flavor decreases) by cutting individual basil leaves or leafy stems. If you harvest/cut the plants back every few weeks, it will encourage new growth and dealy flowering. To extend the growing season, cut plants down to within a few inches of the ground to get a second and even a third crop. A little bit of fertilizer after pruning is helpful.
Basil Propagation.
Allow some of the strongest plants to remain uncut. Seeds should be ripe by mid-autumn.
Winter/Indoor Basil Use.
Transplant from the garden or sow seeds in early September. Sow seeds two to the inch and transplant seedlings into pots or boxes. A standard 4-inch pot is the perfect size for a single plant. If grown in flats, basil plants should be spaced 5 to 6 inches apart in each direction.