Grow cacti in full light with some shelter from the hottest sun. An average temperature of 10- 23°C (50-75°F) is ideal. Many Cacti can tolerate lower temperatures down to a minimum of 5°C (40°F).Sowing InfoSow seeds in to good, freedraining, potting soil. Place in a well-lit room with an average room temperature of 10-23°C - (50-75°F) are preferable. Requires a bright but lightly shaded spot, away from the direct glare of the sun.Growing InfoGrow cacti in full light with some shelter from the hottest sun. An average temperature of 10- 23°C (50-75°F) is ideal. Many Cacti can tolerate lower temperatures down to a minimum of 5°C (40°F).