Aloe gariepensis will struggle to be away from its natural home to assure success it will need hot weather conditions. For an even better chance at success consider growing the succulent in a pot as this will allow you to have more control over the conditions and environment surrounding your plant.
If you want to achieve optimal flowering be sure to plant or place your plant in full sun.
Raised rock gardens that have good drainage are the best environment. Growing this aloe is best achieved with seeds, and slow integration is essential. The seeds should be sown while they are still fresh. If kept for too long they will be invaded by small crawling insects. It is best to sow in late summer and treat your seeds to a long-lasting fungicide to protect them from getting a fungus that can kill young plants.
When planting use coarse river sand and cover the seeds lightly keeping it moist.
When the plants are 20-30mm high after germination you must replant the seedlings using a sandy loam medium and feed it with an organic fertilizer once a quarter for healthy growth. Take note that mature plants can be attacked by scale or aphids. If this does happen it is best to remove the scale with a cloth. All garden pests and disease can be limited by ensuring your succulent is kept in optimal growing conditions.