Propagating thyme: cuttings, seeds & division

Stephanie
Stephanie
Stephanie
Stephanie

I love to grow, particularly herbs and medicinal plants but also fruits, vegetables and plants for the home. I work as a horticulturist, specifically with plants for indoor spaces, and I study in my spare time. I live in the city but seek out green spaces and those which bring nature and growing into the community.

Favourite fruits: fresh peaches and blueberries
Favourite vegetables: leek, spinach, kale, mushrooms

Thyme makes a popular addition to any garden, windowsill or kitchen. This hardy and low-maintenance plant is also very easy to propagate in a variety of ways.

Thyme shrub growing outdoors
Propagating thyme is possible from seed, cuttings or division [Photo: Insanet/ Shutterstock.com]

Common thyme (Thymus vulgaris) is an easy to care for and robust shrub. If you would like for your thyme crop to multiply, it is quite easy to do so without buying new seedlings. Here are several methods for propagating thyme.

Propagating thyme from seed

With a little patience, it is possible to grow thyme from seed, with either those that you have collected yourself or seeds bought from a shop. Purchased seeds are much more reliable and your best choice for growing thyme from seed. Self-harvested thyme seeds may grow into plants that are quite different to the mother plant, as thyme interbreeds very easily. You can of course sow your own self-harvested seeds if you do not necessarily want a true or particular variety of thyme. Of the three ways of propagating thyme presented in this article, from seed is the least straightforward. The following steps will help you to grow thyme from seed should you like to give it a go:

  • Sowing thyme: sow seeds indoors at the end of February or in-situ from April.
  • Soil: a specialist seedling compost is required, such as our Plantura Organic Herb & Seedling Compost. Its low nutrients and good structure encourage seedlings to grow strong and healthy roots.
  • Fill a propagation tray with the compost, press the soil down well and water with a spray bottle.
  • Scatter the fine seeds evenly over the moistened soil.
  • The seeds can be gently pushed down but do not plant thyme seeds deeply or cover them with soil as thyme requires light to germinate.
  • Cover the propagation tray with see-through film or a plastic lid to create an optimal humid environment in which the seeds can germinate.
  • Place the tray in a warm light place that is protected from direct sunlight.
  • At a temperature of around 16 °C, the first seedlings should begin to appear after 2 weeks, although this can take up to 3 or 4 weeks.
  • During this time, it is important to keep the compost moist and to ventilate the propagation tray each day for a few minutes.
  • As soon as the seedlings are visible, the plastic cover can be removed. After about 4 – 5 weeks, prick out the thyme seedlings and plant three or four specimens in each larger pot.
  • The plantlets may take a little time to acclimatise to the unprotected conditions outside of the propagation tray.
Organic Herb & Seedling Compost, 20L
Organic Herb & Seedling Compost, 20L
star-placeholder star-placeholder star-placeholder star-placeholder star-placeholder
star-rating star-rating star-rating star-rating star-rating
(4.8/5)
  • Perfect for herbs as well as sowing, propagating & transplanting
  • For aromatic herbs & healthy seedlings with strong roots
  • Peat-free & organic soil: CO2-saving composition
£12.49

Tip: mix the fine seeds with sand at a ratio of 1:1. This helps to distribute them evenly when you are sowing your thyme seeds.

Propagating thyme from cuttings

Thyme propagates easily from cuttings. This method is particularly good for true-to-type propagation, as it produces clones of the mother plant. Here is our step-by-step guide for how to propagate thyme from cuttings:

  • Propagating from cuttings is possible all year. However, it is best to do so in the growing season during the spring and summer.
  • Choose a suitable growing medium, such as our Plantura Organic Herb & Seedling Compost. Mix in a third sand to make the soil even more permeable and an additional handful of composted material as a starter fertiliser.
  • Suitable cuttings are healthy, young, non-woody shoots, which have not yet flowered.
  • Using a sharp knife, cut the sprigs to a length of 5 – 8cm, directly under a leaf base or node.
  • Remove the leaves from the lower half of the shoots and plant the cuttings individually.
  • To do so, fill small planting pots with the compost and create a planting hole with a pencil, into which you can plant the cutting. Press the soil around the cutting down firmly and then water.
  • A temperature of around 20 °C, high humidity, no direct sunlight and regular watering will ensure the optimal conditions for good rooting.
  • When the cuttings have developed new roots, they can be planted out in the garden or in a larger pot. It takes around 6 – 8 weeks for new roots to form.

Tip: propagation by layering is even easier. Here, a shoot is simply bent over so that it makes contact with the ground. It is held in place there with a piece of wire or a stone. If you are lucky, roots will form after 3 to 4 months, at which time the offshoot can be separated from the mother plant and moved to a new location.

Taking thyme cuttings
Young healthy shoots are the best choice when selecting thyme cuttings [Photo: TanitJuno/ Shutterstock.com]

Dividing thyme

In the case of old and very woody thyme plants, it is best to propagate them by division. This way a plant that is no longer active or vigorously growing can be divided in order to grow into many small and healthy thyme plants. After 3 to 4 years, thyme begins to enter senescence – at this point it is time to divide it. It is best to do so in the spring, allowing the new thyme plants to establish themselves in their new location before winter. With a little luck, they will bloom right away.

First, carefully dig up the old thyme plant, including the rootstock, being careful not to damage any roots. Remove any diseased parts of the plant as well as the middle section, which is old and woody. With the help of a spade or a clean sharp knife, divide the rest of the thyme bush into smaller plants, each with its own root system. Now you can replant the thyme plants around 30cm apart from one another and water them well.

Thyme plant growing outdoors
Dividing thyme is an excellent option for large older shrubs [Photo: Ritvars/ Shutterstock.com]

Now that you know how to propagate thyme to multiply your crop, why not read our dedicated article about the benefits and uses of thyme.

Subscribe to the Plantura newsletter