Black, highly textured hair grows at an average rate of 1/2 inch per month. While there is little difference in the growth rate of highly textured and less textured hair types, lack of length retention can give the false impression that black hair cannot grow long. The truth is that black hair thrives when it is properly moisturized, strengthened and protected.

Black hair can be dry and prone to breakage due to the coily and curly structure of hair strands or daily styling abuse. Keeping dryness at bay is the foundation to growing black hair. Hair needs to be conditioned after every shampoo. In fact, the website Daily Glow recommends that you use conditioner in place of shampoo for extra moisturization. Conditioners without silicone derivatives contain enough detergent to gently cleanse the hair and scalp. Apply a leave-in conditioner to the ends daily.

Cathy Howse, author of "Ultra Black Hair," says black hair needs regular strengthening treatments to grow to its fullest potential. Increasing your daily intake of protein will provide nourishment to the hair follicles, but applying strengthening treatments to the hair's surface is also beneficial. Using mayonnaise as a homemade hair strengthening treatment is economical and effective. Thoroughly detangle highly textured hair before strengthening, then apply 2 to 3 tbsp. of mayonnaise to the hair. Place a plastic shower cap over the hair and allow the mayonnaise to sit in the hair for 20 minutes. Focus on the ends, and avoid applying the mayonnaise to the scalp. Rinse the mayonnaise from your hair with conditioner and warm water.

As long as you are healthy, your hair is growing. Whether that growth results in visible gains in length depends on how healthy you manage to keep the ends of your hair. According to Daily Glow, using chemical or thermal hair straighteners to make black hair stick straight will only destroy the ends and prevent length retention. Have a low-maintenance hair style to help preserve the ends and retain length. Always detangle highly textured black hair starting from the ends. Make sure that hair styles don't put too much tension on the scalp and hair line because this can lead to a type of hair loss called traction alopecia.