Thyme’s name was derived from the Greek word thumus, or courage. In Medieval times, knights wore sprigs of thyme on their armor as a sign of courage.
Sprouts in 2-3 weeks. Harvest from Month 3+ on.
Equivalent of 5+ hours of direct sun [DLI of 15+ mol/m²/day].
Beginner friendly. You’ll sprout, thin, prune, and harvest.
How to Grow Thyme Indoors: Best Thyme Varieties to Grow Inside
So what really is the answer to the question “how to grow thyme indoors?” First, you need to consider which of its varieties you can grow indoors. Dozens of varieties are available for thyme, but I have listed the most common upright and creeping thymes, that you can grow indoors.
It plays well with all its Mediterranean pals, including rosemary, oregano, marjoram, and sage. It’s also taken by mouth for bronchitis, whooping cough, sore throat, etc.
It may be added to poultry, seafood, vegetable, marinades, stews, soups, sauces, and stuffing while fresh sprigs of this herb make a lovely garnish.
It is used as a flavoring in food. The leaves, and especially the essential oil contained in them, are strongly antiseptic, deodorant and disinfectant.
Growing Thyme Indoors: Best Setup for Thyme Plants
To start growing thyme indoors, you’ll need:
Ceramic Self Watering Planter or pot that is at least 6″ / 1 quart.
At the start: Balanced Blend. This should be equal parts nitrogen, phosphorus, and potassium (with NPK numbers like 10-10-10).
Ongoing: Herb Blend. This should be high in nitrogen (with NPK numbers like 10-5-5).
A strong grow light that can give the equivalent of 5+ hours of direct sun [DLI of 15+ mol/m²/day].
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How to Grow Thyme Indoors: Preparing your Planter & Watering Schedule for Thyme
Growing thyme indoors is relatively easy, but take note that they don’t do well in moist soil conditions. The roots are not accustomed to being too wet and will rot in boggy conditions. On the other hand, if the soil dries out completely the roots will die back and the plant won’t recover. This can catch you off guard because the plant’s not very expressive (its leaves don’t wilt) so it will look fine right up until it dies.
A Ceramic Self Watering Planter filled with a free-draining potting mix self-regulates to keep the soil on the drier side, but with a little consistent moisture (and means no watering guesswork for you). Careful of wick-based self-watering planters with Thyme – as they tend to be too wet.
To set one up:
- Fill up the planter with dry soil from the bag, gently tamping down the top.
- Dump the soil into a large mixing bowl and add water until the soil is moist, but not sopping wet (about ½ Cup)
- Mix in 1 tablespoon of the Balanced Blend Plant Food.
If you are using a regular pot instead, it should be a little bit bigger (at least 6″ / 1 quart and will need drainage holes to prevent it from being over watered. Let the top of the soil dry out between watering.
Starting your Thyme: Seed vs Cutting vs Nursery Plant
New Thyme plants can be started from seed, propagated from an established plant, or purchased live at many garden centers. When growing thyme indoors, we prefer to sprout from seed or propagate from a stem cutting, as it results in plants that are adapted to your growing conditions and limit the chances that you accidentally bring home pests.)
How to Plant Thyme seeds
Thyme grows quickly from seed. Plant 1 site in a 6″ / 1-quart container. In larger containers, space sites 4″ apart. For each site plant press 4 seeds into the surface. Keep the soil warm ( 60-70°F, ideally 65°F). Sprouts typically appear in 21 days but can be as quick as 14 days or as long as 28 days depending on your conditions. Don’t cover the seeds as light helps them sprout. To speed things up, you can soak them in water for 12-24 hours before planting.
Propagating Thyme: How to Clone from a Stem Cutting
If you’ve already got a Thyme plant you love (or a friend does!) you can easily “clone” it with just sharp scissors and a clean glass of water. First, cut a couple 6” shoots of new growth (avoid anything woody). Next, remove the lower leaves, so the bottom half is just stem. Place in a glass of 3” of water, making sure the cut leaf spots are underwater. Place the glass on a bright windowsill and change the water every few days. In a couple of weeks, roots should emerge and you can transplant them into your container. While using additional rooting hormones won’t hurt, it’s not necessary with Thyme plants.
- Cut 6” section of new growth
- Remove leaves halfway and place them in the water on a sunny window sill
- Wait 42 days for a few ½ inch roots to form and carefully transplant into it final container
How to Transplant Thyme
Live starter plants give you a big jump start on your first harvest. When you’re in a garden center – pick the bushiest plant available (tall and lanky ones will be weak growers) and give it a good inspection for pests. Leaves should be dark green without holes, spots, or curled edges. A best practice is to actually “quarantine” your plant for about a week after bringing it home to make sure it’s free and clear of ride-on pests.
Ensuring it’s pest and disease-free it’s time to transplant your seedling into its final home.
- Remove some soil from its final planter – leaving enough space for the bottom of the seedling to be just higher than the soil surface.
- Hold on to the base of the stem with one hand, and turn the pot over while gently pulling the seedling. Giving the pot a few squeezes can help dislodge it.
- Place in its final container and fill around it with soil so that it’s tight, but not compacted.
Where to grow your Thyme plants
Like all edible plants, Thyme plants need lots of light to grow and develop good flavor. Sunlight is excellent for plant growth (and free!) and you might be lucky enough to have a spot that’s got the 5+ hours of direct sun they need. Even with a bright window, it’s unlikely that you’ll have enough natural light in the winter so we recommend a grow light for anyone who wants a constant supply of flavorful produce. For an introduction to grow lights, head over to our post on grow lights for indoor gardeners. We’ve also got a buying guide for screw in types, but to keep things simple in this guide, we’ll just provide directions for the 24W Screw in Bulb by Sansi, which we think is a good middle-of-the-road option.
How bright should your grow light be?
Thyme plants need the equivalent of 5+ hours of direct sunlight [DLI of 15+ mol/m²/day] to grow their best. In order to provide an equivalent amount with a grow light, it needs to be pretty bright! The 24W Sansi bulb should be placed 6 inches away from the top of the plant. This will give your PPFD (the standard measure of brightness) of 500 μmol/m²/s.
How many hours per day do your Thyme plants need under a grow light?
Thyme plants are what’s known as “day-neutral” so can grow under a range of daylight lengths. In order for them to get enough light, we recommend setting up a timer to leave it on for 10+ hours per day.
Thyme Plants Grow Faster in Warmer Temps
Thyme plants are called “warm-weather crops” and will speed up their metabolism when temperatures are warmer. On the other hand, if things get too hot they’ll wilt and become prone to disease. Ideal temperatures are around 70°F but anything between 65 and 85°F grows well.
Week 2-3: Check for Sprouts
You could see seedlings in as little as 14 days (though 21 days is more typical). If it’s been 28 days and you still don’t have any sprouts, it’s likely that your setup is too cold.
Week 5: Thin Your Seedlings
Thin your planter to only have 1 seedling per site – leaving the largest plant. If you are using the reccomended planter (at least 6″ / 1 quart) this will mean you’ve got 1 plant after thinning. By getting rid of the smaller seedlings, you’re allowing the biggest and strongest one to flourish by reducing its competition for water, food, and space.
If your seedlings are under 1 inch, stretching out, or folding over, it’s likely that they don’t have quite enough light.
Month 2: How to Prune Thyme Plants
Once your Thyme plant has 3 sets of mature leaves you’re ready for your prune. Cut off the top set of mature leaves, leaving the bottom two (it’s best to cut right above the pair of leaves you’re keeping on the plant). Once these branches grow out (and each has a few sets of their own leaves) you can cut the tip – just as you did with the main stem. At this point your plant will be fairly well shaped, so hone your inner Bonzi master and use your thinning and heading cuts to harvest and shape your herbs as you go.
Month 3+: How to Harvest Thyme
For peak flavor, harvest right before flowers start to open by cutting the plant ~1.5″ from the ground
Year 10+: End of Life
Thyme can live for a very very long time if the conditions are right.
Shop This Blog
The right supplies can take the guesswork out of caring for your plants – and turn care from a daily to weekly routine as you also understand how to grow thyme indoors. Through our grow tests, we’ve found these products to produce the best indoor Thyme (and also have simple maintenance). Plants are adaptable and can grow in many different conditions, so they are by no means necessary if you already have other supplies.
Best Containers for Thyme: Ceramic Self Watering Planters
Plants thrive on consistent moisture but can suffer if they’re waterlogged. A semi-porous ceramic self regulates ideal conditions. Our favorite is the COSWIP planter. Runner up is XS Self Watering Planter by Wet Pot.
Best Soil for Thyme: Free Draining Mix
Thyme needs a drier environment – so you are better off using a free-draining cactus potting mix – we like this Organic Mix by Espoma.
Best Nutrients for Thyme: Balanced Blend followed by Herb & Lettuce Blend
Thyme likes to start with nutrients that are equal parts nitrogen, phosphorus, and potassium (with NPK numbers like 10-10-10). For this Balanced Blend we recommend: Dr Earth All Purpose
Once they are growing, it’s better to use plant food that is high in nitrogen (with NPK numbers like 10-5-5). For this Herb Blend, we recommend: Joyful Dirt All Purpose
Best Light for Thyme: DIY or Soltech
There is a very small chance that you have the bright windows needed to grow these without a grow light. If you are looking for a higher-end option – we love the Aspect Light by Soltech. For a more affordable option, a DIY setup using a 24W Screw-in Bulb by Sansi with a Clamp Light and Mechanical Timer works well too. Check out our complete guide on a DIY setup for less than $40 or our buying guide for screw in bulbs.