How I Grow Thyme From Seeds (a must for home cooks)

Thyme is a must for all home cooks. There, I said it again.

I use fresh thyme for meat, fish, and vegetarian dishes. And it is a given as a base in many of my spice mixes.

TL;DR: Sprinkle seeds on top of pre-moistened soil mix and cover lightly. Mist seeds lightly and cover the pot to help maintain even soil moisture. Remove the cover when you see the first leaves, and place the pot in a location with plenty of sun.

Thyme is a relatively easy herb to grow and care for. Unlike thirstier herbs like basil and cilantro/coriander, thyme will quite happily accept a mild dry-out every now and then.

And it gets better.

Thyme is a perennial herb, and even here in Zone 7, our thyme plants grow back every year.

This article will show you how I start thyme from seed and grow strong, healthy plants that deliver fantastic flavors every year.

How to grow thyme (detailed, easy-to-follow steps)

Looking for more detail or clarification? Read on to get all the deets.

1. Fresh seeds: It all starts with fresh, quality seeds. Avoid using last year’s leftovers; after all, seeds are dirt cheap.

2. Soil mix: Go soil-less or follow my lead and use quality potting soil.

3. Starter pots: Use starter pots or a seed starting tray. But avoid using large pots or containers as more soil makes it harder to control soil moisture.

Wash them carefully if you reuse pots or containers from other gardening projects. Make sure the containers have drain holes.

4. Fill the chosen pot with your potting soil. The seed contains all the energy needed to germinate, so there is no need for fertilizers. Pre-moisten the soil mix before you fill your pots. You want moist, not wet.

Premoistening the soil mix makes it easier to maintain even soil moisture and helps remove air pockets in the soil mix. 

5. Sprinkle the seeds sparingly on top of the soil mix: The seeds are tiny, but try to leave some space between each seed. Remember, one seed equals one potential plant.

6. Cover the seeds with a thin layer of soil mix: Use soil mix or vermiculite to cover the seeds lightly. Press gently with your fingers to ensure solid contact between soil and seeds. Mist with water and cover the container with a plastic film (or lid). 

7. Place the container in a warm – not hot – place: Think warm; if you are comfortable, the seeds will be fine. Keep the soil mix moist. If you see condensation forming on the inside of the cover, make some holes in the plastic to provide better air circulation. 

8. Patience, thyme seeds can be slow to germinate: After about 21 days, you should start seeing the first leaves forming. Remove the plastic film, and keep the soil moist. Keep the container in a warm place with plenty of sunlight. 

You want a warm environment of 18-22 degrees Celsius (64-70 degrees Fahrenheit) with plenty of sunlight (at least 6 hours per day). But avoid direct sunlight as you risk scorching the seedlings. 

If you are using a soil-less mix, give half the recommended dose of a balanced liquid fertilizer (NPK 10-10-10) weekly.

9. Transplanting or potting up: When the seedlings have grown at least two sets of true leaves, it is time to transplant them into larger pots or containers. Fill the new pots with nutrient-rich potting soil.

Lift the seedlings gently, taking great care not to damage the root system, and plant them to the same depth as before. Leave approximately 10 cm (4 inches) between seedlings as you plant them. If you use nutrient-rich soil, you do not have to add fertilizer.

As the seedlings grow, increase their exposure to sunlight. Mature thyme plants will thrive in full sun.

Thyme seedlings with several sets of true leaves
Thyme seedlings with true leaves

10. Transplant outdoors (optional): When there is no longer any risk of frost, you can replant the thyme plants in your herb garden or place the pots outdoors. You should always harden your plants for 1-2 weeks by gradually increasing their outdoor time.

11. Harvest continually: As the thyme plant grows, harvest continually by pinching twigs 3-6 cm (1-2 inches) above ground level. Continually harvesting your plant will create new growth and result in a bushier and healthier plant.

12. Harvesting the whole plant for re-growth: When my thyme plants flower towards the end of the season, I harvest the whole plant. Cut it back, leaving 3-6 cm (1-2 inches), and watch the plant grow back. Water thoroughly and use a standard balanced fertilizer at half the recommended dosage to boost your plant.

13. Coping with problems: Thyme is a hardy plant, and the most common problem you may encounter is root rot due to overwatering, compact soil or poor drainage.

Established thyme plants prefer a mild dry-out between waterings to constant wet and overwatering.

The more common pests include aphids and red spider mites. Early detection and treatment with Neem Oil will help save your plant.

14. Help your plant stay healthy over winter: Ensure your soil drains well and place a thick layer of mulch around the bottom of the plant as the weather gets cooler. Do not apply the mulch too early in the fall, as you may overheat the root system.

15. Giving old plants a new lease on life: Your thyme plant will develop woody branches after a few years. Cutting the plant back hard in the spring, leaving only 3 cm (1 inch), can help rejuvenate your plant.

There you have it, follow these steps and you will have success.

Thyme Varieties, Aroma And Color

Thyme is part of a large family of herbs, including varieties like English, French, Silver, Lemon, and then, of course, the most popular – common thyme or Thymus Vulgaris.

And if you want to grow thyme for the first time, I recommend you start with common thyme. 

Thyme is a low-growing perennial bush-like plant with long stems covered with small, oval green to grey-green leaves.

When thyme flowers, the plant produces small delicate white, pink, or even red flowers that are favorites among pollinators like bees.

Thyme plant with white delicate flowers
White flowers on thyme

The branches grow stiff and wooden as the plant matures. Mature thyme plants benefit from being harvested continuously throughout the growing season. 

Thyme is a very aromatic herb, and low-growing creeping varieties are known to be planted in between paving stones in English gardens. The leaves emit a wonderful scent should they occasionally be stepped on. 

Thyme is best added to your dishes early in the cooking process and provides a rich and earthy flavor with floral undertones. 

It takes a bit of patience to grow thyme from seed. You can harvest the plant the first year, but the yield will be much richer in years two and onwards.

You can also grow thyme from cuttings or divisions to speed up the process.

If you grow from seed, you start propagating indoors in starter pots in early spring. 

Harvesting Thyme

Harvesting thyme is as simple as cutting off sprigs or branches as needed.

I prefer to use fresh thyme. But, as winters are quite cold here in Zone 7, I also dry thyme for cooking and spice mixes.

Drying Thyme

It is really easy to dry thyme. You can invest in a dehydrator, but it is not a must-have to dry thyme.

My favorite method to dry thyme is really easy.

Tie branches of thyme together and place them in a brown paper bag. Hang the bag upside down in a cool, dark location with good ventilation.

The branches can take several weeks to dry depending on external factors like temperature and humidity,

When dry, remove the leaves from the branches using your fingers and store them in an airtight container. 

You can, of course, also use a food dehydrator. Depending on the model, drying your thyme in a food dehydrator can take 1-20 hours. 

Freezing thyme

You can freeze entire thyme sprigs or remove and freeze the leaves in a plastic bag or container.

Cut the amount of thyme you want to freeze.

It is optional to rinse and wash the thyme. I don’t. I shake it and brush it off using my hands.

If you wash your thyme, leave it on the branch, as it must be dry before you freeze it. 

You can remove the dry leaves from the branch or freeze the entire branch with leaves and all.

I freeze entire branches.

Place the thyme in a plastic bag or container and remove as much air as possible.

Seal the bag or container and place it in your freezer for storage. 

Summary and conclusion

Thyme is one of those herbs that can be used for almost any type of cooking. You can use it with meat, fish as well as vegetarian cooking.

Thyme growing alongside peppermint and rosemary
Peppermint, thyme, and rosemary in my herb garden

Thyme can be grown from seeds, cuttings, or by division from an established plant. You can, of course, also start by buying a small plant from your local garden store if you prefer.

Thyme is a perennial, and propagating a healthy plant can start a long and fruitful relationship. 

Thyme is very hardy and will tolerate the occasional mild dry out and even poor soil. But thyme will not tolerate overwatering or compact and poorly drained soil. 

Helpful sources:

University of Illinois Extension

Planttalk Colorado™ sponsored by Colorado State University Extension, Denver Botanic gardens, and the Green Industries of Colorado

Mattias Magnusson: Hello, I'm Mattias, a passionate and experienced gardening enthusiast. I am the creator of MattMagnusson.com, your guide to year-round herb and veggie growing. Let's simplify green living, no matter your space or location.