Torenia needs light to germinate, so do not cover, but simply tamp the seeds firmly into the soil so as to have adequate soil contact and water gently but well. Watering from the bottom will prevent dislodging the seeds until they’ve sprouted. Not a good candidate for transplant, we suggest you start Torenia in seed trays with pots or soil plugs that can be removed and transplanted with little if any stress to the seedlings. If sowing directly into the garden, you can plant them about a week before the last expected frost date. The trick to a good germination rate is to keep the soil consistently moist and the soil temperature consistently between 70 and 72°F. Once they’ve sprouted, they can survive cooler temperatures. Pinch the new growth on the plants when they’ve reached 2 to 3-inches in height in order to encourage better branching for a bushier plant.