How can I grow healthy hair?

Hi, I am a black woman. I cut my hair when I was about 15 and I am now 21. My hair is just above my shoulders and it has been the same length for a long time. What can I do to help it grow? What products do you use?How can I grow healthy hair?
If this comes out sounding racist I SO don't mean it! It's really hard for black women to grow out their hair, I have a ton of black friends and have seen them get so frustrated about it. The best thing you can do is eat A LOT of greens. Mainly Spinach, become Popeye, I'm not kidding. Green leafy veggies have been proven to make your hair healthier and shinier since it works as an anti-oxidant. I would suggest a weave, but since your hair is already to just about your shoulders, it's up to you. Try putting it into a really tight ponytail when you're at home and see if that will help. Also taking vitamins can help, something with Keratine. A really good one is Hair, Skin and Nails by Nutrilite. Hope I helped :)