The more texture to the hair, the easier this style will be to accomplish. The nature of thicker or frizzier hair tends to make it easier to hold this style together. Naturally straight hair slips out of this style more often than textured hair, due to its more slippery nature. The minimum length of hair required for cornrows with the wearer's natural hair is about 1.75 inches. When braiding cornrows, which are braids attached to the scalp in rows, you need enough hair to grip as you braid. The hair that's added to the braid, or cornrow, should be long enough to incorporate into the braid without falling out of it. Part hair in straight rows beginning at the hairline and going back to the nape of the neck. Begin braiding a small section of hair at the front of the head and pull in hair from the section that you're braiding to affix it to the scalp, forming a cornrow. Continue braiding all the way to the ends of the hair. You may need barrettes or rubber bands to hold the ends together.
Hair should be at least two inches long when braiding hair extensions into cornrows. Besides needing sufficient length to hold the cornrow style in place, you also need enough length to hold the weight of the additional hair. For hair that's only two to three inches in length, avoid very long extensions. The heavy weight of long hair additions may pull on your short hair. Once your hair is at least four to five inches long, you can wear longer extensions without worry that they'll slip out. Begin braiding cornrows as you would without extensions, but feed in extension hair at the same time you incorporate hair from the section you're braiding. Braid the extensions at least one inch past the end of your natural hair. If you cut and burn the extensions (for synthetic hair only, not human hair), you don't want to cut or burn your hair, which is why extensions should fall past your natural hair length.
Minimum length for cornrows Cornrows FAQ