Valerian is valued for its many culinary and medicinal uses. Although valerian is most commonly grown outdoors in a herb garden or flower bed, growing valerian as a houseplant is no more difficult than growing it outdoors. Like most herbs, the secrets to success are well-draining soil and plenty of bright sunlight. For the best chance of success, start with fresh, high-quality valerian seeds.
Fill a planting tray with commercial potting mixture that has been pre-moisted. To moisten the potting mixture, put the mixture in a bowl or bucket, and add warm water until the potting mixture is moist, but not dripping wet. Excessive moisture will prevent the valerian seeds from germinating.
Sprinkle a few valerian seeds on the top of the potting mixture and press the seeds lightly into the potting mixture with your fingers. Valerian seeds are tiny, and covering the seeds will block the sunlight.
Spray the top of the potting mixture lightly to settle the seeds. Cover the tray with clear plastic and put the tray in a warm, sunny spot. Avoid putting the valerian seeds directly in a sunny window, because the sun will magnify through the plastic and burn the seeds.
Check the potting mixture often and mist inside the plastic when the potting soil feels dry to the touch. The environment inside the plastic must be warm and humid in order for the valerian seeds to germinate.
Loosen the plastic when the valerian seeds emerge from the soil. When the valerian seedlings are 1 to 2 inches tall, remove the plastic and repot the healthiest seedlings in a 3- or 4-inch container. Move the seedlings into a sunny spot. If sunlight is limited, supplement available light with a grow light.
Repot the valerian plants to containers one size larger when the plants outgrow their containers. Be sure the container has good drainage holes in the bottom, as the bottom of the pot should never be allowed to stand in water.