How to Grow and Care for Lemon Thyme

Close up of lemon thyme leaves in a herb garden with its typical lilac colored flowers.

Yuliia Bilousova/ Getty Images

Lemon thyme is a Mediterranean herb that has been used to treat illnesses for centuries. Once believed to be a hybrid of garden origin, between Thymus pulegioides and Thymus vulgaris, it has since received its classification after DNA analysis revealed it is its own species (Thymus citriodorus).

 The aesthetic appeal and the many uses of lemon thyme in garden design are reason enough to plant this aromatic treasure. Using lemon thyme in a garden can bring interest and appeal in various ways. Lemon thyme makes an excellent border plant in a rock garden and thrives in those conditions. If looking to xeriscape, thyme is perfect and will give a pop of color when it flowers or, depending on the cultivar, can add yellows and lime greens as well.
 

Botanical Name Thymus citroidorus
Common Name Lemon Thyme
Plant Type  Herb
Mature Size 6 - 12 in. tall, 12 - 18 in. wide
Sun Exposure Full sun
Soil Type Dry to medium, well-drained soil
Soil pH Neutral
Bloom Time July
Flower Color Lilac
Hardiness Zones USDA 5-9
Native Area  Southern Europe
Toxicity Non-toxic

Lemon Thyme Care

Whether you are growing lemon thyme for culinary, medicinal, or ornamental uses in a fixed spot in your landscape or a container, this olfactory delight is relatively carefree. Give your citrusy herb a little water, plenty of light, and some nice warm weather, and it will give you its fresh lemony leaves from spring till the first frost. What is extra special about the herb is that it can be grown indoors as long as you have bright light.

Light

Lemon thyme demands bright sunny locations that recall its origins. It will tolerate some shade, but it will never thrive and give its best foliage or aroma in anything but the full sun. If your yard lacks a location that gets full sun, lemon thyme grows wonderfully in containers and can be kept on a sunny window sill.  

Soil

When thinking of ideal soil conditions for lemon thyme, consider the native conditions of where it originally lived. In thyme’s case, this would be the dry, sandy, rocky limestone mountainsides of the Mediterranean. This environment creates the perfect dry, alkaline soil needed for growing lemon thyme. While these conditions are ideal, lemon thyme and many Mediterranean herbs will grow in
almost any soil condition since they are adapted to growing rocky, infertile soil.

Water

Watering lemon thyme is a low-maintenance affair. Lemon thyme prefers dry conditions, so watering it weekly or even every few weeks is fine. Once the soil is truly dry to the touch, water the soil until it's drenched.

Temperature and Humidity

Lemon thyme thrives in warm, dry weather, so it reaches its peak performance during the summer. This is when you will see the lovely lilac flowers bloom, as well as reap the benefit of the volatile lemony essential oils released by the warm air. It will go dormant during the cooler months but may remain green throughout the year in all but the coldest climates.

Fertilizer

Treating herbs, not just lemon thyme, with fertilizer is often a bad idea. A great way to be proactive and encourage vigorous growth is to add some organic compost when planting.

Is Lemon Thyme Toxic?

No, lemon thyme isn't toxic to humans or animals. It's an edible herb.

Growing Lemon Thyme From Seed

Growing lemon thyme from seed is possible, but it is often slow to germinate.

  1. In a seed starting tray filled with seed starting medium, place two to three seeds per cell. Keep the medium consistently moist. A domed cover will help you keep the seeds warm and the soil moist and warm. Put the trays in a bright window or under a grow light on a heating mat.
  2. When your seeds have germinated, remove the dome place a small fan beside the tray to allow indirect air to flow over the seedlings at all times. The constant pressure from the air creates more robust plants and root systems.  
  3. When your plants reach a height of three inches or so, move them into pots to allow them to mature a little before planting outdoors.
  4. Harden off the seedlings before you take them outside after the first frost.

Propagating Lemon Thyme

Once you have an established plant, you can easily propagate thyme. Cutting is a common propagation method.

  1. Cut a stem section 4 inches in length with sterile scissors or snips just below the leaf node.
  2. Remove the leaves below the node, then submerge the stem of the cutting in distilled water. Put the cuttings in a place that gets plenty of light.
  3. Within a few weeks, the plant’s roots will have begun developing. Let a good root system develop, then transplant it into a pot to grow further.

Alternatively, you can dip cuttings in a rooting hormone and push the cutting into seed starting soil. Keep the soil moist and within a few weeks the plant's roots will have begun to develop.

Potting and Repotting

If you plan to propagate thyme or want to grow thyme in a container rather than in the garden, having a great potting mix is essential. Start with a base of three parts seed mix, two parts compost, one part vermiculite, and one part topsoil. This mix will give you the suitable organics, draining, aeration, moisture retention, and texture for your herb to be happy.