Herb · Lamiaceae
Creeping Thyme
Thymus serpyllum
Give it full sun and sharp drainage and creeping thyme rewards you with a tough, fragrant carpet that takes drought in stride.
Full sun
Every 10–14 days
USDA 4–9
1–4 in · 2–10 cm
Overview
If you are nervous about your first groundcover, creeping thyme is a kind place to start. It is a low, woody member of the mint family that settles into a dense evergreen mat only an inch or two high, and the moment you brush a hand across it the leaves release that warm, herby thyme scent. You can lean on it to fill the gaps between pavers, soften a wall edge, or cover bare ground where grass keeps failing you.
What makes it so forgiving is how little it minds. After it has put down roots it copes with drought, thin stony soil, and cold winters without complaint, staying hardy right through USDA zones 4 to 9. Come early summer the whole carpet vanishes under little pink-to-purple flowers, and the bees will thank you for it.
There is really just one thing to get right, and once you do, the rest falls into place. Sharp drainage and full sun keep it happy, while rich soil or soggy roots will set it back faster than any bug. Pick a good spot at planting time and you can relax, because from there it mostly takes care of itself.
Care
The short version: give it full sun and lean, gritty, sharply drained soil. Water deeply but seldom once it has settled in, leave the fertilizer in the shed, and shear it back after it blooms to keep the mat full and happy.
Light
Creeping thyme loves full sun, and the more it gets the better it does. It will manage in partial sun, but the mat turns thin and floppy and the flowers grow scarce, so reward it with the brightest, most open spot you can offer.
Water
Once it has settled in this plant is truly drought-tolerant and would rather stay on the dry to medium side. Water deeply but seldom, only every 10 to 14 days through a dry stretch, and let the top half of the soil dry before you reach for the can. Soggy ground is the single thing it cannot forgive.
Soil
Keep it lean and you keep it happy. Plant into loose, sandy, gritty or rocky soil with sharp drainage, and the poorer the better, because rich ground softens the plant and dims its flowering. It is easygoing about pH and takes anything from 6.0 to 8.0.
Temperature
This is a wonderfully cold-hardy plant that handles a big swing, all the way from -29°F to 86°F (-34°C to 30°C). Hard winters do not trouble it, and it shrugs off summer heat just fine as long as the soil keeps draining.
Humidity
It is happiest on the dry side and has no fondness for muggy air. Good airflow does it far more good than any humidity number, since still, damp conditions are what invite rot and mites in the first place.
Feeding
Go gentle, or honestly just skip it. Creeping thyme is a light feeder, and rich soil works against it by trimming both its winter hardiness and its bloom. A small spring feed is plenty if you feel like bothering at all.
Pruning
Shear or trim the stems back after flowering to neaten the mat, keep its spread in bounds, and slow the woody buildup that thins the center as the years go by. One trim a year is all it takes to keep it dense and looking its best.
Size & spacing
Each plant stays low, just 1 to 4 inches (2 to 10 cm) tall, while it spreads into a mat 12 to 18 inches (30 to 45 cm) wide. Space your plants about that far apart and they will knit together into solid, even cover.
When to plant
Creeping thyme is a hardy perennial, which means you plant it once and it comes back to greet you every year. Start your seed indoors in late winter, move plants outside in spring once the frost has passed, and the mat will flower all summer while you pick the leaves whenever the mood strikes.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Sow: Late winter to early spring, 6-8 weeks before last frost
- Plant: Spring, after danger of frost has passed
- Harvest: Tiny deep pink to purple flowers appear early-to-mid summer (June-September) and are highly attractive to bees; aromatic leaves can be harvested anytime.
Hardiness
USDA hardiness zones: 4–9
Temperature: down to -34°C
Troubleshooting
Tucked into the right spot, creeping thyme rarely gives you grief, and nearly every hiccup comes down to too much water or simply an aging mat. Don't worry if something looks off, because the early signs below are easy to catch, and a little timely action usually puts things right before a patch gives up.
Dark, softened stem bases and a sinking patch of mat
Take heart, because this is root and crown rot and not some disease you have to spray away. Wet, badly drained soil or one too many trips with the watering can smothers the roots until they go soft and sour-smelling. Cut out the dead bits, work some sand or grit into the ground to loosen it up, and water a good deal less, and the healthy parts will pull through.
Fix:
- Remove affected sections
- Improve drainage by amending with sand or grit
- Reduce watering frequency
- Replant healthy divisions in a faster-draining site
An open, twiggy gap at the heart of the mat
There is nothing to fix and nothing wrong, because this is just the natural woody aging of the oldest central stems. The middle goes brown and leafless while the green outer ring keeps right on creeping. Shear the whole mat after it flowers to wake up fresh growth, and every few years lift and divide those vigorous outer pieces to begin again.
Fix:
- Shear back after flowering to encourage fresh basal growth
- Divide and replant vigorous outer sections to rejuvenate
Tiny pale dots and wisps of webbing on the leaves
When hot, dry summer weather settles in, spider mites sometimes move onto the undersides and sip the leaves dry. The fine speckling shows up first, and then the thin webbing as their numbers grow. A strong jet of water knocks them off, opening the planting up for better airflow keeps them away, and insecticidal soap is there only if a few cling on.
Fix:
- Rinse foliage with a strong jet of water
- Increase airflow
- Treat persistent infestations with insecticidal soap or horticultural oil
Toxicity
You can breathe easy here. Creeping thyme is non-toxic all the way around, gentle and safe for cats, dogs, horses, rabbits, livestock, birds, and people too. The fragrant leaves are even edible, so if a curious pet or a small child sneaks a taste, there is genuinely nothing to fret about.
Safe for
People · Cats · Dogs · Horses · Rabbits · Livestock · Birds
Cats None
Safe around cats, so a curious nibble of the fragrant leaves will do no harm at all.
Dogs None
Non-toxic to dogs, which means a pup pushing through the mat or tasting a leaf has nothing to worry about.
Horses Safe
Listed as safe for horses, with no toxic compounds anywhere in the leaves or stems.
Rabbits Safe
Rabbits can graze the foliage without any risk, and plenty of them enjoy the scented leaves.
Livestock Safe
Grazing cattle, goats, and sheep all get along with creeping thyme just fine.
Birds Safe
No hazard to birds, and the summer flowers mostly call in bees rather than posing any threat.
People Safe
Safe for people, leaves and all, and the aromatic foliage is edible, though it is milder than the kitchen thyme most cooks reach for.
No special handling precautions; foliage is aromatic and safe to touch and taste.
Varieties
Most creeping thyme on the shelf is the plain species, and that is a fine choice, but a couple of named selections are lovely to know for their size or their flower color.
Elfin
A tiny, tight little cushion that holds at only about an inch tall, which makes it the friendly pick to tuck between stepping stones.
Coccineus
A spirited mat that opens deep magenta-red flowers, much bolder than the soft pink-purple you get from the plain species.
How to propagate
Making more creeping thyme is a confidence-builder, since you can split an existing mat, root a few cuttings, or sow the species from seed, and all of them are within easy reach.
DivisionEasy
Spring or early fall · 4 to 8 weeks
Lift a settled mat in spring or early fall and gently tease it apart, leaving each piece with roots of its own. The replanted divisions ease in over 4 to 8 weeks, and this is the reliable, beginner-friendly way to copy a named cultivar true to type.
Stem cuttingsEasy
Late spring to summer · 3 to 6 weeks
In late spring or summer, snip softwood cuttings from shoots that are not flowering and stand them in a gritty, well-drained mix. They root with little fuss in 3 to 6 weeks and keep the parent's traits, so a favorite cultivar carries right along.
SeedModerate
Late winter to spring, indoors before last frost · Several weeks to germinate; full mat coverage over a season or more
Seed is the usual path for the plain species. Scatter the tiny seeds on the surface indoors before the last frost and keep them lightly moist, and they take several weeks to sprout and a full season or more to fill in as a mat. Cultivars will not come true this way, so save seed-growing for the species itself.
Myths
The creeping thyme in the garden is identical to the thyme in your spice rack.
They are close cousins, but not one and the same. The thyme in your kitchen is Thymus vulgaris, while creeping thyme is grown mostly as a pretty groundcover. It is edible, just milder, and it rarely finds its way into a recipe.