Lemon Basil: What It Is, What Makes It Lemony, and How to Use It

Lemon basil tastes like basil with lemon peel and a little lime, lighter and less peppery than sweet basil. That lemon note comes mainly from citral.¹ Western seed catalogs sell it under names like ‘Lemon’, ‘Mrs. Burns’ Lemon’ and ‘Sweet Dani’, and its parent, hoary basil, is eaten raw across Indonesia, Malaysia and Thailand. Its botanical name is a tangle, because it’s a cross between sweet basil and hoary basil. Below, we sort out the names, the chemistry and the uses.

At a glance

What lemon basil is

Kew’s Plants of the World Online treats lemon basil’s hybrid as Ocimum × africanum, with the formula O. americanum × O. basilicum, and lists Ocimum × citriodorum, the name most seed catalogs use, as a synonym. Kew gives its native range as tropical and subtropical Asia to Australia, and describes it as an annual or subshrub of the seasonally dry tropics.²

Other references draw the lines differently:

In practice, “lemon basil” covers a few closely related plants. PROSEA notes that crosses between hoary basil and sweet basil are easy to make but have badly reduced pollen fertility.³ The Herb Society guide says ‘Sweet Dani’ was developed by Dr. James Simon at Purdue University and named after his daughter, and that ‘Mrs. Burns’ Lemon’ has been grown since the 1920s.⁵

Flavor and the compounds behind it

Lemon basil tastes like basil with lemon peel and a little lime, lighter and less peppery than sweet basil.

Two studies measured its oil and got different results:

The Purdue authors concluded that citral was the predominant compound in all the lemon-scented basils, even though their own table lists linalool first for two of them.¹ The Thai study found estragole, the anise-scented compound in sweet basil, at the top of its lemon basil oil, with anise and citrus scents dominant.⁴ The two didn’t measure the same plants or use the same units, so don’t average them. Both find citral, and that’s what sets lemon basil apart from sweet basil. PROSEA notes that hoary basil contains citral, camphor and methyl cinnamate in varying proportions, giving cinnamon, clove and lemon smells.³

You’ll often read that limonene drives lemon basil’s scent. Neither study above lists limonene among the main compounds.

How lemon basil is used

• Raw, as a side vegetable. PROSEA says hoary basil is mild and widely grown in Indonesia, Malaysia and Thailand for its young leaves, eaten raw as a side dish. It adds that the fragrant leaves go into dishes with a fishy or unpleasant smell.³
• Seeds in drinks. The seeds swell in water into a jelly that goes into sweet cooling drinks.³
• Desserts and drinks. The Herb Society guide calls lemon and cinnamon basils unexpected but flavorful additions to desserts, and uses lemon basil in muffins, flavored butter, basil syrups and a pineapple-orange cooler. It recommends ‘Mrs. Burns’ Lemon’ for vinaigrettes, drinks and desserts.⁵
• Late in cooking. LSU AgCenter counts basil among the delicate herbs to add a minute or two before cooking ends, because long heating costs flavor and aroma.⁶ Lemon basil is at its best in raw dishes, salads and dressings.

Growing and buying

The Herb Society guide notes that the ‘Lemon’ cultivar sometimes flowers while the plant is still small. It lists the hybrid as needing temperatures of 50°F or higher, and names ‘Lesbos’ among the non-seeding basils, which you have to grow from cuttings.⁵ As with any basil, pinch off flower buds to keep the plant leafy.

When buying, look for perky leaves that smell strongly of lemon when you rub them. We couldn’t find a published shelf-life figure for lemon basil. The usual basil storage methods apply: see how to store basil and can you freeze basil?.

Safety and health claims

Some lemon basils, like the Thai sample above, contain estragole.⁴ The EU Scientific Committee on Food concluded in 2001 that estragole is genotoxic and carcinogenic, mainly based on studies in mice, and couldn’t set a safe exposure limit.⁷ It didn’t single out lemon basil or tell people to stop eating basil. Our basil profile covers that evidence.

The NIH’s National Center for Complementary and Integrative Health has no fact sheet on lemon basil.⁸ We couldn’t find a nutrient analysis of lemon basil itself, so don’t carry sweet basil’s vitamin figures over to it. You’ll see claims that lemon basil’s citral or limonene fights cancer or treats heartburn. No systematic review or health agency we found backs them, and we don’t make them.

Substitutes and comparisons

Sweet basil with a little lemon zest is the usual stand-in. Lemon balm or lemon verbena bring citrus without the basil. We didn’t find anyone who’s tested ratios for these, so go by taste. Related pages:

• Lemon basil vs. basil
• Basil, Thai basil, holy basil and cinnamon basil
• Lemon balm, lemon verbena and lemongrass
• Too much basil