Is Basil a Perennial or an Annual?

Basil (‌Ocimum‌ spp.) is a widely used herb that can be grown in the home garden. Native to Southeast Asia, India and Africa, it is easy to grow and is usually cultivated as an annual plant. It is primarily grown for its leaves, but the flowers of basil are edible too.

Can You Grow Basil as a Perennial?

In its native habitat, basil is a perennial that can survive for more than one growing season. However, these plants are only hardy in U.S. Department of Agriculture plant hardiness zones 10 to 12. Therefore, ‌in most places, basil is treated as an annual.‌ This means that you should plan on replanting it each spring.

Types of Basil

Let's take a look at some of the different kinds of basil.

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Sweet Basil

By far the most widely grown and used type of basil is sweet basil (‌Ocimum basilicum‌), which is known as common basil. There are many cultivars of sweet basil from which to choose that vary in the size and color of the leaves as well as in flavor.

• ‌Genovese:‌ This cultivar can grow up to 2 feet tall and has large, 2-inch leaves. It is the go-to basil for making pesto.
• ‌Sweet Broadleaf:‌ A smaller plant than Genovese, it has a height of up to 18 inches. The leaves are medium-size.
• ‌Purple Ruffles:‌ This kind of basil is grown for its ornamental purple leaves, which are also edible.
• ‌Cinnamon:‌ This cultivar gets its name from its flavor, which is spicier than that of other sweet basils.
• ‌Thai:‌ This popular cultivar grows up to 18 inches, is slightly spicy and is more stable under high or extended cooking temperatures than other cultivars of sweet basil.

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Holy Basil

Holy basil (‌Ocimum tenuiflorum‌) is a variety of basil used in Asian cuisine that has a spicier taste than sweet basil. This type of basil is more commonly cooked into dishes rather than eaten raw. Holy basil grows in shrub form. Shrubs quickly reach a height of about 3 feet.

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African Blue Basil

African blue basil (‌Ocimum kilimandscharicum x basilicum‌) is a hybrid version of basil that, according to the University of Florida IFAS Extension, is grown primarily for its flowers, which are attractive to pollinators, like bees and wasps. It is edible but has a much stronger taste than sweet basil.

The pink flowers of the African blue basil do not produce seeds. This variety of basil can therefore only be propagated by cuttings.

Growing Basil in the Garden

You can sow basil seeds directly into the garden bed in spring after the last frost of the season. According to the University of Minnesota Extension, basil plants perform best in soil that has a pH between 6.0 and 7.5 and drains well.

When planting basil, choose a location where the plants will receive between six and eight hours of sunlight a day. Basil plants also need about an inch of water a week.

Basil can be harvested on an ongoing basis, as that plant will continue to produce leaves from the point where the cut was made. For the best quality and flavor, harvest basil leaves when you are ready to cook with them.