Elfin thymus praecox is usually referred to as creeping thyme. It makes excellent ground cover and is relatively tolerant of soil and watering conditions. If you would like to grow creeping thyme from seeds, follow the steps listed below.
Step 1 - Make a Sprouter
To start Thymus praecox seeds, build a simple sprouter. Cut the egg carton so that you have a section which will fit inside the bottle. Lay the soda bottle on its side and cut a flap that is large enough to insert the egg carton.
Fill the sections of the carton with potting soil or sifted compost. Sprinkle seeds over the soil and very gently mix the top 1/4 inch. Moisten the soil until it is damp throughout. Close the flap on the soda bottle, and seal it with duct tape. Place this instant terrarium in a window sill where it can get direct sunlight.
Step 2 - Pick a Location
While waiting on growing seeds to be strong enough for planting, pick out the location you want to plant in. Loosen the soil thoroughly, and add sifted compost to it. Soak the soil thoroughly and wait 24 hours and loosen the soil again.
Step 3 - Thinning Your Sprouts
After 48 to 72 hours, your seeds should begin to sprout. Remove the duct tape or cut through it, and open the flap. Carefully remove the egg carton. If there are several seedlings in a single cup, thin out the weakest plants, retaining only the tallest and strongest ones. Let your selected seedlings grow in the egg carton for another four to 10 days, watering them lightly only when the soil dries out.
Step 4 - Transfer Plugs
Use a piece of broom handle or pipe to make a hole in the ground about the size of the cups of the egg carton. Cut the cups apart, and remove the seedling by placing your fingers on either side of the plant stem, and then turn the whole thing upside down, sliding the plant soil out of the cup. Place the plug in the hole, and lightly tamp the soil around it. Repeat this step for each plant.
Step 5 - Mulch
Until your plants are around six inches tall, it's not a good idea to try to add mulch. Doing so is likely to break the stems. Once they have reached six inches or so, add about 1/2 inch of sifted compost around the plants. Add two to three inches of mulch on top of that and lightly water the mulch.
Step 6 - Maintain
Check the mulch often, and replace it when necessary. Remove old mulch and add it into your compost bin for recycling. Using sifted compost, add 1/2 an inch to one inch around the creeping thyme. Cover the compost with two to three inches of mulch, and water as normal. The compost will continue to decompose, and will be naturally absorbed into the soil during rains or watering, giving the plants healthy nutrients without disturbing their soil.