Castor oil has been a staple in home hair-care routines for years. It’s thick, sticky and not exactly the easiest oil to work with, but plenty of people swear by it for keeping their hair feeling moisturised and their scalp nourished.The bigger question is what you can mix with it.If castor oil feels too heavy on its own, adding a few lighter, familiar ingredients can make it easier to apply and spread through the hair. Coconut oil, aloe vera, onion oil, rosemary and curry leaves are five popular choices.But there’s a catch. None of these mixtures can guarantee faster or dramatic hair growth. Hair growth depends on things such as genetics, hormones, age, nutrition and scalp health. Still, taking better care of the scalp and reducing dryness and breakage can help your hair look healthier over time.Here’s how each ingredient fits into the routine.