Article: For indoor cacti, keep them near a window where they will receive direct sunlight from outside. For outdoor cacti, plant them in an area where there is full sun. Room-temperature will be fine until winter arrives, when you'll need to give your cacti a "resting period." During winter keep your cacti in an area that is around 50 degrees Fahrenheit (10 degrees Celsius). Do not expose your cacti to temperatures below 41 degrees Fahrenheit (5 degrees Celsius) or above 70 degrees Fahrenheit (12 degrees Celsius) during the resting period. Your cacti needs fertilizer in the summer. Use a high-potassium fertilizer to help your cacti grow faster and encourage flower growth. Look for a slow-release fertilizer at your local gardening store.

What is a summary?
Keep your cacti in direct sunlight. Keep your cacti in an area that is room-temperature if they're indoors. Add a fertilizer to your indoor and outdoor cacti every 4 weeks.