How to Plant, Grow, and Care for Lemon Thyme

Lemon thyme is a must for any herb garden. This versatile, zesty herb has all the savory notes of common thyme with an added sweet citrus aroma and taste!

Its versatility extends to ornamental gardening, with a range of upright and low-growing ground cover and variegated varieties to choose from, with lavender-pink flowers attracting beneficial insects and adding pops of color.   

Used fresh, lemon thyme should be added at the end of cooking to retain flavor. Add leaves to salads, herbal teas, and sweet dishes such as cakes, cookies, and ice cream. It is delicious infused in marinades or vinegar and used in herb rubs for chicken, fish, and potatoes. It also retains its flavor when dried for longer-term storage.

Lemon thyme is cultivated in exactly the same way as common garden thyme. Learn how to grow this versatile plant here.

What is Lemon Thyme?

Lemon thyme, also commonly known as citrus thyme, is a member of the mint family, (Lamiaceae).

It was thought to be a hybrid of Thymus vulgaris (common thyme) and Thymus pulegioides (broad-leaved thyme). However, recent DNA testing has proven lemon thyme to be a separate species and not a hybrid. Due to these new findings, the botanical name for lemon thyme remains Thymus citriodorus as opposed to Thymus × citriodorus. 

Characteristics

Native to mountainous regions of the Mediterranean, thyme is an evergreen, woody shrub-like herb that thrives in arid climates and poor soils. Lemon thyme has its origins in the garden, but is cultivated

Clusters of tiny aromatic lance-shaped leaves a quarter of an inch long grow along young plant stems and vary in color from mid to dark green, streaked with silver, white, and yellow. Lavender-pink two-lipped flowers appear from late spring or early summer and draw in pollinating insects. 

Lemon thyme has an upright growth habit, growing to around 12 inches in height and 12 to 24 inches across depending on variety.

Lemon thyme is grown for leaves, but the flower has the same lemon scent and makes an attractive garnish. The thyme-lemon aroma and flavor are at their best before flowering and when harvested in the morning.

The small size and preference for poor, free-draining soils make lemon thyme plants a natural choice for container gardening. Grow alongside other Mediterranean herbs such as sage and rosemary that enjoy the same conditions. Lemon thyme plants have many uses in the garden as an ornamental and culinary herb.

Cultivars

There are so many lovely cultivars to try, each with unique characteristics that add to a garden’s diversity. These are just a few of our favorites:

‘Archers Gold’

This is a low-growing lemon thyme plant that looks great in rockeries and as a ground cover between pavers. Excellent culinary flavor.

‘Silver Queen’

A stunning ornamental lemon-scented thyme plant with silver-white leaf margins that stand out from other varieties. It grows upright to 12 inches in height. Good culinary flavor.

‘Golden Lemon’, ‘Golden Queen’, and ‘Aurea’

All three of these lemon thyme cultivars are similar in appearance with variegated golden lemon-scented foliage. Similar to ‘Silver Queen’, they stand out from other herbs in the garden and are attractive as an ornamental as well as providing excellent flavor.

‘Lime’

Lime-scented upright thyme plant with bright green leaves growing to 12 inches high. Very citrusy in its aroma.

Planting

Growing lemon thyme from seed may test your patience! Germination can take up to a month and is often sporadic. Sourcing seeds of a specific cultivar can also prove difficult. The best method to propagate lemon thyme is through plantings of vegetative cuttings. These will provide an exact clone of the parent plant.

The best time to plant shop-bought plants and transplants in the ground is after the last spring frost. Prepare a planting hole deep enough to accommodate the root ball but not too deep to cover the main stem as this may cause stem rot. Space plants 12-18 inches apart.

For planting in containers, choose a pot filled with a mix of horticultural grit and compost. Lemon thyme plants grow well indoors on a south-facing windowsill or in a well-ventilated greenhouse.  

How To Grow

Are you new to gardening? If so, lemon thyme is a great herb to start with. Lemon thyme plants thrive in full sun and well-drained soil and will tolerate a bit of neglect.

Light

Grow lemon thyme plants in full sun with at least six hours of sunlight daily. Plants grown indoors as houseplants need a sunny windowsill to grow well. A south-facing window is ideal to get the most sunlight.

If you don’t have enough light, consider adding a grow light to increase the luminosity. Leave it on for 12 hours at a time.

Water

Lemon thyme plants should be watered in the morning when the soil has completely dried out. Watering over the winter is not necessary unless thyme plants are showing signs of drought stress.

Once established, these plants are drought-tolerant. Avoid overwatering which could cause root rot. For indoor potted plants, water only once a week or even every second week. Test the soil before watering to ensure it is completely dry.

Soil

Plant lemon thyme in free-draining sandy soils with a pH ranging from 6.0 to 8.0. Amend heavy clay garden soils with compost and horticultural grit to improve drainage. If the roots are left to sit in soggy water, they will begin to rot and ultimately kill the plant.

Temperature & Humidity

Lemon thyme prefers temperatures ranging from 70 to 85°F (21-29°C). Surprisingly, most thyme plants can survive freezing temperatures and are hardy in USDA zones 5 to 8.

If growing lemon thyme in zones lower than 5, consider planting it in a pot so that you can bring it indoors to overwinter. If growing indoors, maintain low humidity levels and good air circulation.

Fertilizing

Lemon thyme is native to arid mountainous regions with poor, thin soils. It does not require a fertilizer.

A light mulch of compost or leaf mold in autumn and spring will protect roots from frost and provide adequate nutrients for the growing season. For an extra boost, provide liquid fertilizer in spring.

Maintenance

Regular harvesting keeps your lemon thyme in shape and encourages new growth. Prune out any flowers as they appear to prolong maximum citrus flavor and keep the plant productive. 

Unharvested plants may require a hard prune in late fall to prepare them for winter, as frosts can damage soft growth. Prune branches with a sharp pair of pruning shears by a third, saving any clippings for drying.

Perennial lemon thyme plants can become woody with age and need replacing. Regular harvesting and pruning will keep your plants in good condition for longer.

Harvesting

Lemon thyme is simple to harvest and one of the easiest herbs to dry for long-term storage. It’s a must to keep on hand for cooking!

As an evergreen perennial herb, lemon thyme plants have a long harvest season. For the best lemon flavor, harvest in the morning and before a plant flowers in late spring. Plants propagated from seed or cuttings should be ready for harvest around three to six months. 

Snip off as many stems as required and wash thoroughly under running water to remove any bugs and dirt that can be caught in the clusters of tiny leaves. 

Storage

Fresh lemon thyme will store in the fridge for up to a week, wrapped in damp paper towels. For longer-term storage, they need to be dried.

Place leaves in a dehydrator or a low oven or hang stems up in a cool, dark room until dry. Once completely dry, strip the tiny leaves from the stems and store them in an airtight container.

The best flavor will be in the first year for your thyme as lemon notes will fade first as it ages. Unlike other spice varieties, you will find this will last a smidge longer in your spice cabinet while still retaining flavor.

Common Problems

Lemon thyme is usually problem-free. However, incorrect growing conditions may result in weak plants at risk from pests and diseases. Plants will deteriorate if grown in shade. For healthy plants, grow lemon thyme in full sun and well-drained soil.

Pests

Aphids (Aphidoidea), are small, sticky flies that feed on the sap of new plant growth. Treat biologically by encouraging beneficial insects that feed on aphids, such as ladybug larvae (Cococinella septempunctata). Plantings of yarrow, coreopsis, and dill are sure to provide them with habitat.

A quick spray of organic insecticidal soap or neem oil will kill aphids. Squishing them with fingers or a quick blast of water can help reduce numbers. 

Spider mites (Tetranychidae) are reddish-brown, living in large colonies on the underside of foliage. They thrive in hot, dry environments and feed on plant juices. Look out for fine webbing between stems and plants showing signs of decline. 

Spider mites can be resistant to insecticides. Remove and destroy the worst affected parts (and entire plants if necessary) to prevent spread to unaffected areas of the garden. 

Diseases

Botrytis cinerea, commonly known as grey mold, is an airborne disease prevalent in mild, damp weather. It targets weak, damaged, or stressed plants. Symptoms include wilting stems, brown discoloration of foliage, and grey furry fungal growth. 

High air humidity creates the perfect environment for botrytis. Remove and destroy affected plants to prevent further spread. Good plant husbandry methods such as harvesting carefully, keeping the ground clear of decaying debris, watering only when necessary, and providing adequate spacing to allow good air circulation will reduce the risk.

Wet, heavy soils can cause root rot. Plant in well-draining soil that mimics the plant’s natural environment, preferably a sandy blend that allows excess water to flow through. Ensure that potted plants have adequate drainage holes for water to run through and don’t allow pots to sit in trays of water.

Frequently Asked Questions