Succulent seeds can germinate quickly, depending on the species, but that doesn’t mean that they grow quickly. Most succulent seedlings should be left in the original planter for six months to a year before being transplanted.
Depending on the species of succulent, you can generally repot after it has grown to about 2 inches (5 cm) and has a well established root system.
If you’re treating your growing container like a greenhouse, it’s best to remove the lid for good after the first month so that the seedlings get adequate airflow. Prior to that, it’s good to lift the lid every few days for a moment to let new air in, but don’t leave it off for too long.
Most seeds need to be kept at a temperature between 60° and 70° F (15° to 21° C) to germinate. Be sure to keep the seeds watered correctly; you don’t want them to dry out. After replanting, water the small succulent as you would a mature plant.