Lemon Thyme: Hybrid or Species, What’s in Its Oil, and How to Cook With It

Lemon thyme smells of lemon as well as thyme, and next to common thyme it tastes softer and sweeter, with less of that sharp, medicinal edge. Use it anywhere both flavors fit: chicken, fish, vegetables, potatoes, stuffings and salads. Kew lists it as a hybrid, Thymus × citriodorus, while NC State Extension calls it a distinct species. Below: that naming question, the surprisingly variable chemistry of its oil, how to cook with it, and the few safety points that apply.

At a glance

What lemon thyme is

NC State Extension describes lemon thyme as an evergreen subshrub in the mint family, possibly native to Europe, that mounds to 6–12 inches and spreads about a foot. Kew gives its native range as southwestern Europe. Its leaves and flowers are edible, raw or cooked.²

Hybrid or species?

The sources disagree, and you’ll see the disagreement on plant labels:

NC State doesn’t name the study it relies on, and we couldn’t open one. We follow Kew’s checklist across the site, so the name here keeps the ”×”. For common thyme, see thyme.

Cultivars

NC State lists several garden cultivars, including ‘Archers Gold’ and ‘Variegata’ with variegated leaves, ‘Doone Valley’ with leaves tipped in gold in fall and winter, and ‘Silver Queen’ with silver leaves and a lemon fragrance.² We couldn’t find a source describing cultivars named for other citrus fruits, like an “orange thyme” form of lemon thyme.

Flavor and aroma

Lemon thyme adds a citrus overtone to the usual thyme flavor. Next to common thyme it tastes softer and sweeter, with less of that sharp, medicinal edge. Common thyme’s oil is marked by the phenols thymol and carvacrol.⁵ Here’s what’s been measured in lemon thyme.

What’s in the oil

Lemon thyme hasn’t been studied as much as common thyme, and the two studies we could open point in different directions:

We only had the abstracts of both papers, so we can’t give the citral or geraniol percentages from the first study. Don’t merge the two results. They describe different plants grown in different places, and they show that “lemon thyme” oil isn’t one fixed recipe.

Origin and history

Lemon thyme’s native range is southwestern Europe. The word “thyme” came into English from Latin thymum, from Greek thymon. A popular explanation ties it to Greek words for smoke or fumigation. The Online Etymology Dictionary reports that derivation, and also notes that the linguist Beekes thought it doubtful and suggested a pre-Greek origin.⁶

Stories of Dioscorides and Pliny on thyme, and of Roman legions bringing thyme to England, are about thyme in general, and we couldn’t trace them to a source we could open, so they’re left out.

How lemon thyme is used

UF/IFAS Extension says lemon thyme can be used fresh or dried, and in any recipe calling for lemon juice, lemon zest or lemon flavoring.⁷ The leaves and flowers can be eaten raw in salads or cooked.

Good places for it in the kitchen:

• Roast chicken and turkey, and the stuffing that goes with them.
• Fish and shellfish, especially baked or grilled with butter.
• Roast or boiled potatoes, carrots and green vegetables.
• Salads and dressings, using the small leaves raw.
• Shortbread, lemon cakes and fruit, where its lemon side leads.

Its citrus notes are softer than the fruit’s, and lemon thyme won’t replace the acidity of lemon juice. Add a squeeze if the dish needs sourness. It pairs naturally with oregano, basil, parsley and garlic. For more ideas, see lemon thyme uses.

Buying and quality

Fresh lemon thyme should smell of lemon when you rub the leaves. Plants and sprigs vary, and some smell more of thyme than lemon. We couldn’t find a grading standard for lemon thyme.

Storage

We couldn’t find a published shelf-life figure for fresh or dried lemon thyme from a regulator or extension service. What works for common thyme works here; see how to store thyme. For dried lemon thyme, smell is the practical test.

Safety

• US food status. FDA’s GRAS spice list names common thyme (Thymus vulgaris) and wild or creeping thyme (Thymus serpyllum).⁸ We couldn’t find a separate entry for lemon thyme.
• Contaminants. EU law caps pyrrolizidine alkaloids in dried herbs at 400 µg/kg, apart from a short list of named exceptions that doesn’t include thyme.⁹

We don’t claim lemon thyme treats or prevents anything. You’ll see claims that it relieves bronchitis, whooping cough, gastritis or gingivitis, or that it’s a rich source of vitamins, minerals, lutein or zeaxanthin. We couldn’t trace any of them to a source that backs them up for lemon thyme.

Substitutes and comparisons

Common thyme plus a little lemon zest is the closest stand-in. Lemon balm or lemon verbena bring the lemon but not the thyme. See lemon thyme substitutes.

• Thyme vs. lemon thyme
• Profiles: thyme, lemon balm, lemon verbena, lemongrass
• Related: too much thyme, cooking with thyme